On this day in 1801 – January 1st – Giuseppe Piazzi discovered Ceres.Ceres was the first object discovered in what's now known as the asteroid belt. It was at first considered a planet, then an asteroid, and is now classed as a dwarf planet.
On this day in 1925 - January 1st - Edward Hubble read to the American Astronomical Society what would be a ground-breaking paper.He showed that the Andromeda "nebula" wasn't an object in the Milky Way, but a galaxy in its own right. Here is picture of the glass plate on which Hubble discovered a Cepheid variable - marked VAR! - in the Andromeda galaxy. From this he determined that it was too far away to be located in our own galaxy.
On this day in 1959 - January 2nd - the Soviet Union's Luna 1 was the first spacecraft to leave the Earth's gravitational field.
Luna 1 passed to within 6000 km of the Moon, and ended up in orbit around the Sun.
On this day in 1920 - January 2nd - American author and scientist Isaac Asimov was born.
Asimov was a chemistry professor, but also a prolific writer on many subjects. He's best remembered for his works of science fiction and of popular science, including astronomy.
On this day in 2004 - January 3rd - NASA's rover Spirit landed on Mars.Along with the Opportunity rover, the rovers' mission was designed to last for just over three months. Spirit was active until 2010.
On this day in 1643 - January 4th - Isaac Newton was born.Newton was born on Christmas Day 1642, according to the Julian Calendar then in use. When nearly a century later England adopted the Gregorian calendar, the equivalent date was ten days later.
On this day in 1797 - January 4th - German astronomer Wilhelm Beer was born.
Beer was an amateur astronomer, who with Johannes Heinrich Maedler, published the first map of the Moon (Mappa Salenographica). They also made a map of Mars and calculated the planet's rotation period to within 0.1 second of today's figure.
On this day in 1892 - January 5th - the first successful photograph was taken of an aurora.Early cameras couldn't catch the dim light of an aurora, and long exposures didn't capture the movement. German physicist Martin Brendel and a fellow scientist, on an expedition in northern Norway, took the first successful image, and revolutionized the study of the northern lights.
On this day in 2005 - January 5th - Mike Brown's team at Palomar Observatory discovered ErisThe discovery of this distant object that originally appeared to be bigger than Pluto ignited the debate about the definition of a planet. For a time, NASA referred to Eris as the "10th planet", but in the end, both Eris and Pluto became dwarf planets.
On this day in 1998 - January 6th - NASA's Lunar Prospector was launched.
The mission was designed to investigate the Moon from low polar orbit. This would include mapping the surface composition, locating lunar resources, and measuring magnetic and gravity fields.
On this day in 1610 - January 7th - Galileo wrote the first letter in which he described his observations of the Moon through a telescope.
In his time the Moon was assumed to be a perfectly smooth sphere. However Galileo saw that the surface was uneven with mountains, plains and valleys.
On this day in 1610 - January 7th - Galileo first saw three of Jupiter's moons.The three objects he saw in his telescope are now known as Callisto, Io and Europa, three of the four Galilean moons.
On this day in 1942 - January 8th - English theoretical physicist Stephen Hawking was born.
For thirty years he was the Lucasian Professor at the University of Cambridge, a prestigious post once held by Isaac Newton. Hawking also wrote books on cosmology for the general public, the most famous of which was A Brief History of Time. He was most closely with his work on black holes.
On this day in 1587 - January 8th - Johannes Fabricius was born.
Fabricius was a German/Frisian astronomer, eldest son of David Fabricius who was also an astronomer. In their solar observing, they discovered sunspots about the same time as, and independently of, Galileo.
On this day in 1839 - January 9th - Thomas Henderson published his determination of the distance to Alpha Centauri.Henderson had actually been the first person to calculate the distance to a fixed star by using stellar parallax. However he had delayed publishing his results, and the credit for being first went elsewhere.
On this day in 1946 - January 10th - the US Army Signal Corps had the first successful echo detection of a radar signal bounced off the Moon.
It was part of the first experiment in radar astronomy, a technique used decades later to map the planet Venus.
On this day in 1787 - January 11th - William Herschel discovered the Uranian moons Oberon and Titania.It would be almost five decades after Titania and Oberon were discovered that an astronomer other than Herschel would observe them.
On this day in 1907 - January 12th - Sergei Korolev was born.Korolev was the mastermind of the Soviet space program, and a state secret referred to, if at all, as the Chief Designer.
On this day in 2005 - January 12th - NASA's Deep Impact spacecraft was launched.
Deep Impact was the first space mission to study the interior composition of a comet.
On this day in 1610 - January 13th - Galileo discovered a fourth satellite of Jupiter.
This was the moon we now know as Ganymede, the biggest moon in the Solar System.
On this day in 1978 - January 13th - NASA selected its first women astronaut candidates.In 1983 Sally Ride became the first American woman in space.
On this day in 2005 - January 14th - the European Space Agency (ESA) probe Huygens landed on Saturn's moon Titan.It was the first time a spacecraft had been landed on a moon other than our own. Here is footage of the Huygens landing on Titan.
On this day in 2008 - January 14th - NASA's MESSENGER spacecraft made its first flyby of Mercury.
MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) was the second spacecraft to reach Mercury, the first having been Mariner 10 in 1975.
On this day in 1916 - January 14th - the Royal Astronomical Society in London, founded in 1820, finally admitted the first women to full membership in the society.
On this day in 2006 - January 15th - NASA's Stardust spacecraft completed its mission by returning its samples to Earth.
Stardust was robotic space probe whose primary mission was to collect dust samples from the coma of comet Wild 2, as well as samples of cosmic dust.
On this day in 1969 - January 16th - the first docking of two manned spacecraft occurred.
The Soviet Soyuz 4 and Soyuz 5 docked in space and transferred crew from one vehicle to another by a space walk.
On this day in 1969 - January 16th - the UK Space Agency announced that the remains of the probe Beagle 2 had been located on Mars.The probe had been lost on Christmas Day 2003 after successful insertion into orbit by Mars Express. It was finally identified in images from the HiRise camera on the Mars Reconnaissance Orbiter (MRO).
On this day in 1647 - January 17th - Elisabetha Hevelius (née Koopmann), the second wife of Johannes Hevelius, was born.She is considered to be one of the first European female astronomers, and is often called 'The mother of Moon charts'. Elisabetha helped her husband manage his observatory, and published two of his works after his death.
On this day in 2002 - January 18th - the Gemini South Observatory was dedicated.
Gemini South in Chile and Gemini North in Hawaii together constitute the Gemini Observatory. The twin telescopes provide almost complete coverage of the skies with two of the largest and most advanced optical/infrared telescopes available.
On this day in 1747 - January 19th - Johann Bode was born.Although his name lives on in "Bode's Law", he was, more importantly, a celestial cartographer who created two influential sky atlases.
On this day in 1851 - January 19th - Jacobus Kapteyn was born.
Kapteyn was a Dutch astronomer best known for his studies of the Milky Way. He was the first to discover evidence that galaxies rotate.
On this day in 2006 - January 19th - NASA's New Horizons spacecraft was launched.
The spacecraft made a flyby of the Plutonian system in the summer of 2015, and on New Year's Day 2019, followed it up with a flyby of the Kuiper Belt object informally called Ultima Thule, but later renamed Arrokoth.
On this day in 1930 - January 20th - Edwin "Buzz" Aldrin was born.The second man to step onto the Moon has been not only an astronaut, but also an Air Force combat pilot, aerial gunnery instructor and flight commander. His doctoral thesis at MIT was on techniques for manned orbital rendezvous.
On this day in On this day in 1573 - January 20th - German astronomer Simon Marius was born.Marius claimed he had seen Jupiter's moons before Galileo. Galileo's documentation was more extensive and published first, so he got the credit. However, the suggestions Marius made for naming the four large moons were eventually adopted.
On this day in On this day in 2014 - January 20th - ESA's Rosetta spacecraft awoke from a deep space hibernation of over thirty months.Rosetta's historic mission saw her then catch up with a comet, go into orbit around it, put a lander on its surface, and follow the comet as it went around the Sun.
On this day in 1908 - January 21st - Danish astronomer and astrophysicist Bengt Strömgren was born.
He applied quantum mechanics to understanding stars, produced pioneering work in the chemical composition of stars, and discovered vast shells of ionized hydrogen around stars, now known as Strömgren Spheres.
On this day in 1592 - January 22nd - Pierre Gassendi was born.Gassendi was a French philosopher, priest, astronomer, and scientific observer, experimentalist and chronicler. He was the first person ever to see a planet transiting the Sun when he observed the 1631 transit of Mercury.
On this day in 2003 - January 22nd - Pioneer 10's last signal was received.
Pioneer 10 was the first spacecraft to pass through the asteroid belt, and later the first to pass the orbit of Pluto. Originally designed for a 21-month mission, it lasted more than 30 years.
On this day in 1986 - January 24th - Voyager 2 flew past Uranus.This fly-by was the first and only visit of a spacecraft to Uranus.
On this day in 2004 - January 25th - the Mars rover Opportunity landed on the red planet.
The mission was designed to last 90 Martian days, but it was operational until the summer of 2018 when an exceptionally severe dust storm blanketed Mars for three months. The rover didn't recover from the loss of power, and the mission was officially brought to an end in February 2019.
On this day in 1994 - January 25th - Clementine was launched.
Over a period of nearly four months the US spacecraft Clementine made scientific observations of the Moon. In addition, the craft was used to test the effects on sensors and components of extended exposure to space.
On this day in 1736 - January 25th - French mathematician Joseph Lagrange was born.
Lagrange was one of the great minds of the 18th century, and his work included major contributions to physics and astronomy. He's best known now for his identification of equilibrium points between the gravity of the Earth and that the Sun. NASA's SOHO (Solar and Heliospheric Observatory) sits at one of these points.
On this day in 1983 - January 25th - the Infrared Astronomical Satellite (IRAS) was launched.
IRAS, a joint project of NASA (USA), NIVR (Netherlands) and SERC (UK), was the first space telescope to carry out a survey of the whole night sky at infrared wavelengths.
On this day in 1978 - January 26th - the International Ultraviolet Explorer (IUE) was launched.
The IUE was a joint effort by ESA, the UK Science Research Council and NASA. It was switched off in 1996, after it had worked 14 years beyond its planned lifetime.
On this day in 1967 - January 27th - the crew of Apollo 1, Virgil "Gus" Grissom, Edward White and Roger Chaffee, died when fire swept through the command module during a preflight test.They are commemorated at the Astronaut Memorial at the Kennedy Space Center in Florida.
On this day in 1941 - January 27th - New Zealand astrophysicist Beatrice Hill Tinsley was born.Beatrice Tinsley began her career late, and died in 1981, but in the intervening years she revolutionized our view of galactic evolution. Her pioneering work continues to be regularly cited by researchers.
On this day in 1829 - January 27th - pioneering astrophotographer Isaac Roberts was born.Roberts was a Welsh amateur astronomer, and a fellow of the Royal Geological Society. He developed a photographic technique which made it possible to capture faint objects. Roberts's photograph of the Andromeda Nebula actually showed the spiral structure of M31.
On this day in 1986 - January 28th - NASA's space shuttle Challenger exploded soon after launch, killing the seven crew members.They are commemorated at the Astronaut Memorial at the Kennedy Space Center in Florida.
It's one of those memories that stays with you for eternity.
I agree, Monika. It's always so heart-wrenching to think of it. And instantly see in your mind the launch footage where suddenly the spacecraft breaks up. The anniversary of the third of the trio of NASA disasters is on Saturday.
On this day in 1611 - January 28th - Polish astronomer Johannes Hevelius was born.Johannes Hevelius studied sunspots, produced a lunar chart, discovered several comets, and compiled an important star atlas. He was one of the most influential astronomers of the 17th century.
On this day in 2003 - February 1st - NASA's space shuttle Columbia broke up during re-entry, killing the seven crew members.They are commemorated at the Astronaut Memorial at the Kennedy Space Center in Florida.
On this day in 1995 - February 3rd - the first space shuttle mission with a woman pilot was launched.
Eileen Collins was the first woman to pilot a space shuttle. Four years later she became the first woman commander of a space shuttle.
On this day in 1966 - February 3rd - the Soviet spacecraft Luna 9 made the first successful soft landing on the Moon.
Luna 9 also sent back the first pictures taken on the Moon's surface.
On this day in 1906 - February 4th - Clyde Tombaugh was born.Tombaugh was the American astronomer who discovered Pluto. He died in 1997, and a portion of his ashes were on the New Horizons spacecraft that journeyed to Pluto.
On this day in 1963 - February 5th - Dutch astronomer Maarten Schmidt had a sudden insight that provided the clue to solving the mystery of quasars.Schmidt realized that a quasar wasn't an object in our Galaxy, and its unusual spectrum wasn't full of unknown elements. It was mostly composed of hydrogen that was redshifted because of its enormous distance away in an expanding Universe.
On this day in 1974 - February 5th - NASA's Mariner 10 took a historic gravity assist from Venus in order to make its flyby of Mercury.
It was the first spacecraft to turn the theoretical possibility of such a gravity assist into a reality, and it enabled the first visit of a spacecraft to Mercury.
On this day in 1971 - February 6th - Alan Shepard hit the first golf balls on the Moon.
The Apollo 14 lunar module landed on the Moon on February 5th with lunar module pilot Ed Mitchell and commander Alan Shepard. Shepherd hit the golf balls on their second exploration of the Moon.
On this day in 1999 - February 7th - NASA's Stardust comet probe was launched.
Stardust was the first sample return mission to collect samples of cosmic dust, and of dust from a comet's coma, then return them to Earth.
On this day in 1984 - February 7th - NASA astronaut Bruce McCandless made the first untethered spacewalk during space shuttle mission STS-41B.
On this day in 1826 - February 8th - Jules Verne was born.
The French author was a major European literary figure best known in the English-speaking world for his exciting and influential adventure stories, many of which are considered early science fiction. Ray Bradbury said "We are all, in one way or another, the children of Jules Verne."
On this day in 1974 - February 8th - the last crew to occupy NASA's Skylab left it.
Skylab, the first US space station, was launched in May 1973. The Skylab 4 crew was the last to occupy it.
On this day in 2010 - February 11th - NASA's Solar Dynamics Observatory (SDO) was launched.The SDO observes the Sun in order to understand the ways in which it affects the Earth, such as space weather.
On this day in 2001 - February 12th - NASA's NEAR Shoemaker spacecraft landed on the asteroid 433 Eros.
NEAR (Near Earth Asteroid Rendezvous) Shoemaker was the first spacecraft to make a soft landing on an asteroid.
On this day in 1852 - February 13th - Johan Dreyer was born in Copenhagen.
Dreyer was a prominent astronomer and writer. He was born in Denmark but became a British citizen. Dreyer is best remembered for his New General Catalogue of Nebulae and Clusters of Stars (based on the Herschel catalogues of nebulae). The catalogue numbers are still in use, prefixed by NGC.
On this day in 2011 - February 14th - NASA's Stardust-NExT spacecraft made a close flyby of comet Tempel 1.
It was NASA's second visit to Tempel 1, because the Deep Impact mission had visited it in 2005, sending an impactor in order to learn about the comet's interior.
On this day in 1980 - February 14th - NASA's Solar Maximum mission was launched.
Solar Max was designed to investigate solar phenomena, particularly solar flares.
On this day in 2000 - February 14th (Valentine's Day) - NASA's NEAR-Shoemaker spacecraft went into orbit around the asteroid Eros.
The asteroid was named for Eros, the Greek god of love, son of the goddess of love Aphrodite.
On this day in 1990 - February 14th - NASA's Voyager 1 took a Family Portrait, looking towards the Sun from 6 billion km away.Earth is only one pixel of the image, christened by Carl Sagan "the pale blue dot".
On this day in 1564 - February 15th - Galileo Galilei was born in Pisa, Italy.Galileo was one of the first to use a telescope to observe the heavens. He's known for his astronomical discoveries, his experimental physics, his astronomical discoveries, and, of course, his getting in trouble with the Church.
On this day in 2013 - February 15th - a meteor explosion occurred over Chelyabinsk in Russia causing around 1500 injuries.The meteoroid was about 20 meters across with a mass of 12,000-13,000 metric tonnes. Fortunately, the explosion occurred high in the atmosphere and the atmosphere absorbed much of the energy. However the shock waves caused a lot of damage, and many of the injuries were from flying glass.
On this day in 1973 - February 15th - Pioneer 10 became the first ever spacecraft to cross the asteroid belt.
Pioneer 10 was launched in 1972, and is is now over three times as far away from the Sun as Pluto.
On this day in 1948 - February 16th -Gerard Kuiper discovered Miranda, a moon of Uranus.
On this day in 1996 - February 17th - NASA's NEAR Shoemaker spacecraft was launched.
The spacecraft went on to do a fly-by of asteroid Mathilde and then studied asteroid Eros from orbit.
On this day in 2018 - February 17th - it was the 5000th sol for NASA's Mars rover Opportunity on the red planet.
Opportunity's mission was originally planned for 90 sols. A sol is a Martian day, and it's just over 39.5 minutes longer than an Earth day. A severe planet-wide dust storm in the summer would finally end Opportunity's amazing mission.
On this day in 1723 - February 17th - German cartographer and astronomer Tobias Mayer was born.
Mayer's chart of the full moon was the standard for half a century, but he's best known for his lunar tables. The accuracy of the lunar positions (and the theory behind them) enhanced the lunar distance method for determining longitude at sea. It enabled navigators to find longitude accurately to half a degree.
On this day in 1930 - February 18th - Clyde Tombaugh discovered Pluto.
Pluto was considered to be the ninth planet for many years. It's now the largest known Kuiper Belt object, and is classified as a dwarf planet.
On this day in 1677 - February 18th - Jacques Cassini was born at the Paris Observatory.
He was the son of the director of the observatory Jean Dominique Cassini, with whom he made numerous astronomical observations. Eventually, he took over his father's duties as head of the Paris Observatory and continued the astronomical work.
On this day in 1986 - February 19th - Mir was launched by the Soviet Union.
Mir was the first modular space station and was assembled in orbit. It was the first continuously inhabited long-term research station in orbit. The failing station was deorbited in March 2001.
On this day in 1473 - February 19th - Nicolaus Copernicus was born in Torun, Poland.His work De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres) set out his arguments for a heliocentric (sun-centered) system instead of a geocentric (Earth-centered) system.
On this day in 1965 - February 20th - John Glenn became the first American to orbit the Earth.
Glenn's space capsule Friendship 7 took him around the Earth three times before its splashdown.
On this day in 1965 - February 20th - NASA's Ranger 8 ended its mission by a crash landing on the Moon.
Ranger 8 was the first NASA spacecraft to take high resolution close-up images of the Moon's surface. It transmitted over 7000 images, intended to help choose landing sites for Apollo missions, before its own mission ended.
On this day in 1744 - February 21st - Dutch astronomer Eise Eisinga was born.
He built the Koninklijk Eise Eisinga Planetarium at his house in Franeker, Netherlands. The orrery still exists and is the oldest functioning planetarium in the world.
On this day in 1978 - February 22nd - the first Navstar GPS satellite was launched.
What is now called the Global Positioning System (GPS) was originally called Navstar GPS.
On this day in 1945 - February 23rd - Ukranian astronomer Svetlana Gerasimenko was born.
Gerasimenko's name is well known because she was the co-discoverer of comet 67P/Churyumov-Gerasimenko. This was the comet explored by the Rosetta mission. Both the Rosetta spacecraft and the lander Philae are on the comet as it continues to orbit the Sun.
On this day in 1990 - February 23rd - Pioneer 11 crossed the orbit of Neptune on its way out of the Solar System.
Although on that date the spacecraft went beyond the most distant planet, since there are dwarf planets and many other objects beyond Neptune, the spacecraft still hasn't left the Solar System. It's now over 100 times farther from the Sun than the Earth is.
On this day in 1987 - February 23rd - the light from supernova SN 1987A reached Earth.
The supernova occurred in the Tarantula Nebula in our neighboring galaxy the Large Magellanic Cloud. It was the closest supernova seen in nearly four hundred years, visible to the unaided eye in the southern hemisphere. It has greatly increased our understanding of this spectacular phenomenon.
On this day in 1968 - February 24th - the discovery of the first pulsar was announced.A pulsar is a fast-rotating neutron star that emits a beam of electromagnetic radiation. We can only detect it when it's pointing towards us, rather like a lighthouse, so it seems to pulse. A neutron star is the remnant of a massive star following the collapse of its core in a supernova explosion.
On this day in 1842 - February 26th - Camille Flammarion, French astronomer and popular author, was born.
On this day in 1897 - February 27th - French astronomer Bernard Lyot was born.
Bernard Lyot's work brought him major international awards. His most important contributions to astronomy were in solar observing, especially the invention of the coronagraph which makes it possible to observe the Sun's corona without waiting for a total eclipse.
On this day in 2007 - February 28th - the New Horizons spacecraft flew past Jupiter en route to Pluto.
New Horizons made over 700 observations of the Jovian system, but the main reason for the flyby was to carry out a gravity assist maneuver. That boosted the speed of the spacecraft to get it to Pluto five years earlier than it would have otherwise.
On this day in 1966 - March 1st - the Soviet probe Venera 3 landed on Venus, the first Earthly craft to land on another planet.
Unfortunately, when the probe entered the atmosphere, ground control lost contact with the orbiting spacecraft. Therefore any data it may have collected couldn't be transmitted.
On this day in 1965 - March 1st - the first foundation piles were laid for ESTEC (European Space Research and Technology Centre) at Noordwijk in the Netherlands.
ESTEC is the European Space Agency's main technology development and test centre for spacecraft and space technology.
On this day in 1982 - March 1st - the descent stage of Soviet probe Venera 13 landed on Venus.
It was the first Venusian probe to transmit color pictures from the surface of the planet. Designed to survive for half an hour, it transmitted data for over two hours.
On this day in 1927 - March 1st - American astronomer George Abell was born.
Abell's catalogue of galaxy clusters from the Palomar Sky Survey remains an important piece of work. But in addition to being an active professional astronomer, he was a teacher, administrator, writer and science popularizer.
On this day in 2004 - March 2nd - the European Space Agency (ESA) launched the Rosetta spacecraft.Rosetta would travel for ten years and billions of miles in order to rendezvous with comet 67P/Churyumov-Gerasimenko, accompany it as it moved through the inner Solar System past the Sun, and also deploy a lander.
On this day in 1972 - March 2nd - NASA's Pioneer 10 was launched.
Pioneer 10 was the first spacecraft to cross the Asteroid Belt and to complete the first mission to Jupiter. It's now over 123 AU from the Sun, heading out of the Solar System in the direction of the constellation Taurus.
On this day in 1979 - March 4th - Jupiter's rings were discovered by theVoyager 1 spacecraft.The rings are dark and made up mainly of dust, so had not been seen from Earth.
On this day in 1923 - March 4th - Sir Patrick Moore, English amateur astronomer, writer and broadcaster, was born.He was best known as the enthusiastic and knowledgeable presenter of the BBC TV program The Sky at Night, which he began in 1957. Although Sir Patrick is no longer with us, the program goes on and is the world's longest-running television series.
On this day in 2005 - March 5th - the European Space Agency (ESA) officially inaugurated its first deep space ground station.
The New Norcia facility in Western Australia was the first, but it's since been joined by stations in Spain and Argentina. Deep space tracking stations are essential for missions such as Rosetta and Mars Express.
On this day in 1512 - March 5th - Gerardus Mercator was born.
Mercator was a German-Flemish cartographer, geographer and cosmographer. He created the 1569 world map based on a new projection that represented sailing courses of constant bearing as straight lines - an innovation that is still employed in nautical charts.
On this day in 1937 - March 6th - Valentina Tereshkova was born.Valentina Tereshkova was the first woman in space. She was a Soviet cosmonaut who spent three days orbiting in Vostok 6.
On this day in 1787 - March 6th - Joseph Fraunhofer was born.
Fraunhofer was a German optician who was known for the quality of his optical glass and excellent telescope objectives. His name is still known today for his discovery of the dark absorption lines - known as Fraunhofer lines - in the Sun's spectrum.
On this day in 2015 - March 6th - NASA'S Dawn spacecraft went into orbit around dwarf planet Ceres.Dawn had already orbited the asteroid Vesta before becoming the first spacecraft to visit a dwarf planet.
On this day in 1792 - March 7th - John Herschel was born.Son of the discoverer of Uranus, John Herschel was one of the 19th century's most distinguished individuals. He was a brilliant mathematician, chemist and astronomer, as well as an accomplished artist, musician and linguist.
On this day in 1837 - March 7th - Henry Draper was born.Henry Draper was a pioneer of astrophotography. Following his early death, his wife Anna donated money to Harvard College Observatory to complete his catalogue of stellar spectra. If you see a deep sky object named with an "HD" prefix, it refers to this catalogue.
On this day in 1831 - March 7th - King William IV signed a Royal Charter for the Astronomical Society of London, and it assumed the name Royal Astronomical Society.
William IV also agreed to be the Society's Patron; every subsequent British monarch has followed suit.
On this day in 2009 - March 7th - NASA launched its planet-hunter Kepler.
During its two missions the space telescope found 2700 confirmed exoplanets and 3000 possibles for further investigation.
On this day in 1979 - March 9th - astronomer Linda Morabito discovered evidence of volcanic activity on Jupiter's moon Io.She found the picture of the first active volcano known outside Earth among the images sent back by Voyager 1.
On this day in 1564 - March 9th - German pastor and amateur astronomer David Fabricius was born.
Along with his son Johannes, David Fabricius discovered Mira, the first known periodic variable star. They also made the first confirmed observations of sunspots.
On this day in 1934 - March 9th - Yuri Gagarin was born.Soviet pilot and cosmonaut Yuri Alekseyevich Gagarin was the first person to orbit the Earth.
On this day in 1977 - March 10th - rings were discovered around the planet Uranus.
The rings were found by a team of astronomers who were using the occultation by Uranus of star SAO 158687 to study the planet's atmosphere.
On this day in 1811 - March 11th - French mathematician and astronomer Urbain LeVerrier was born.LeVerrier's calculations enabled the Berlin Observatory to discover the planet Neptune.
On this day in 1835 - March 12th - Canadian-American mathematician and astronomer Simon Newcomb was born.
Newcomb made important contributions to international timekeeping and other fields in applied mathematics such as economics and statistics. He was a professor at the United States Naval Observatory and at Johns Hopkins.
On this day in 1781 - March 13th - William Herschel discovered the planet Uranus.He was the first person in history to discover a new planet.
On this day in 1885 - March 13th - Percival Lowell was born.
Lowell was an American businessman, author, mathematician, and astronomer. He founded the Lowell Observatory in Flagstaff, Arizona and began the effort that led to the discovery of Pluto 14 years after his death.
On this day in 1879 - March 14th - Albert Einstein was born.
Einstein is definitely a man who needs no introduction.
On this day in 1855 - March 14th - Italian astronomer Giovanni Schiaparelli was born.
Schiaparelli produced the most detailed map of Mars ever published, and it became a standard reference in planetary cartography. When he referred to canali (channels) on Mars, it was translated into English as canals, and Percival Lowell and others were convinced that there was an advanced civilization on Mars.
On this day in 1935 - March 14th - Apollo astronaut Eugene Cernan was born.
Cernan, the commander of Apollo 17, was the last man on the Moon.
On this day in 2016 - March 14th - Part 1 of the joint ESA/Roscosmos ExoMars astrobiology mission was launched.
The launch of the spacecraft containing ExoMars Trace Gas Orbiter (TGO) and Schiaparelli lander was successful. (TGO is now in orbit around Mars, but the lander crashed.)
On this day in 1932 - March 15th - Apollo astronaut Alan Bean was born.
Bean was the Apollo 12 lunar module pilot, and the fourth person to walk on the Moon.
On this day in 1713 - March 15th - French astronomer Nicolas-Louis de Lacaille was born.Lacaille was one of astronomy's greats. He surveyed nearly 10,000 stars in the southern hemisphere, and invented fourteen new constellations still in use today.
On this day in 1750 - March 16th - Caroline Herschel was born.Caroline Herschel was an assistant to her brother William. She also discovered eight comets and a number of deep-sky objects. She was the first woman to be awarded a Gold Medal by the Royal Astronomical Society.
On this day in 1930 - March 17th - Apollo astronaut Jim Irwin was born.
Irwin was the Apollo 15 lunar module pilot and eighth person to walk on the Moon.
On this day in 2011 - March 17th - NASA's Messenger spacecraft went into orbit around Mercury.
Messenger was the first craft ever to orbit Mercury.
On this day in 1965 - March 18th - the Soviet spacecraft Voskhod 2 was launched.
On this mission, cosmonaut Alexei Leonov became the first person to leave a spacecraft for a "spacewalk".
On this day in 1865 - March 21st - Antonia Maury was born.The American astronomer was best known for her work at Harvard College Observatory.
On this day in 1997 - March 22nd - Comet Hale-Bopp made its closest approach to Earth.The two-tailed comet was probably the most widely observed comet of the twentieth century. It's also known as the Great Comet of 1997.
On this day in 1749 - March 23rd - Pierre-Simon Laplace was born.
Laplace was a brilliant French mathematician, astronomer, and physicist who is sometimes called "France's Newton". He accounted for the observed deviations of planets from their theoretical orbits by applying Newton's theory of gravitation to the problem.
On this day in 2001 - March 23rd - the Soviet/Russian space station Mir was deorbited.
Mir was the first space station assembled in orbit and the first continuously inhabited long-term orbital research station.
On this day in 1840 - March 23rd - American polymath John William Draper produced the first detailed photograph of the Moon.It was the first astrophotograph taken in North America.
On this day in 1893 - March 24th - German astronomer Walter Baade was born.
Baade, who worked at Mt Wilson Observatory in California for many years, defined two distinct populations of stars, and his discovery that there are two types of Cepheid variable star meant that his recalculation of the known universe doubled the size calculated by Hubble.
On this day in 1665 - March 25th - Christiaan Huygens discovered Saturn's moon Titan.The European Space Agency (ESA) Titan lander was named for Huygens, a prominent 17th century Dutch mathematician and scientist.
On this day in 1972 - March 27th - the Soviet probe Venera 8 was launched.Venera 8 made the first completely successful landing on Venus, and sent data from the surface for fifty minutes before succumbing to the intense pressure and searing temperature.
On this day in 1802 - March 28th - Heinrich Olbers, German physician and astronomer, discovered Pallas.
Pallas was the second asteroid to be discovered, and it was counted as a planet at the time, as Ceres had been.
On this day in 1807 - March 29th - Heinrich Olbers, German physician and astronomer, discovered Vesta.
Olbers discovered Vesta almost five years to the day after his discovery of Pallas. Vesta was the third asteroid to be discovered, and it was also counted as a planet at the time. Like Ceres, it's been visited by NASA's Dawn mission.
On this day in 1974 - March 29th - NASA's Mariner 10 spacecraft made what was the first ever flyby of Mercury.
On this day in 1997 - March 31st - The Pioneer 10 mission officially ended.
NASA's Pioneer 10 was the first spacecraft to go through the asteroid belt and the first to fly by Jupiter. After the end of the mission, for a time there was still contact with the spacecraft to record telemetry as it headed out into the Kuiper Belt. It's currently about 126 AU from Earth.
On this day in 1997 - April 1st - Comet Hale-Bopp made its closest approach to the Sun.
The comet was dubbed the Great Comet of 1997 and was probably the most widely observed comet of the 20th century.
On this day in 1845 - April 2nd - French physicists Leon Foucault and Louis Fizeau took the first successful photograph of the Sun.
On this day in 1867 - April 3rd - German astronomer Wilhelm Tempel, observing in Marseilles, discovered Comet 9P/Tempel 1.
in 2005 the comet was the target of NASA's Deep Impact probe.
On this day in 2014 - April 3rd - ESA satellite Sentinel 1-A was launched from Europe's Spaceport in French Guiana, the first in the Copernicus EU programme.
Copernicus is the world's largest Earth observation programme, monitoring many aspects of the environment.
On this day in 1693 - April 3rd - English clockmaker John Harrison was born.
Harrison invented the marine chronometer, solving the problem of calculating longitude while at sea. It revolutionized navigation and greatly increased the safety of long-distance sea travel.
On this day in 1966 - April 3rd - the Soviet spacecraft Luna 10 was inserted into orbit around the Moon.
It was the first spacecraft to go into orbit around the Moon, and the first human-made object to orbit any body beyond the Earth.
On this day in 1973 - April 5th - NASA launched Pioneer 11.
Pioneer 11 was the first spacecraft to encounter Saturn and it followed Pioneer 10 into the far reaches of the Solar System.
On this day in 1965 - April 6th - Intelsat I became the first commercial communications satellite to be placed in geosynchronous orbit.
It was nicknamed Early Bird from the proverb "The early bird catches the worm." Although the satellite remains in orbit, the last time it was activated was in 1990.
On this day in 1991 - April 7th - the Compton Gamma Ray Observatory (CGRO) was deployed by astronauts on the Space Shuttle Atlantis.
It was the second of NASA's "Great Observatories" and it transformed our knowledge of the high-energy sky, producing the first ever all-sky survey in gamma rays.
On this day in 2001 - April 7th - NASA's Mars Odyssey orbiter was launched.
The orbiter was designed to look for evidence of past or present water and ice, as well as study the planet's geology and radiation environment. Its primary mission was meant to last 32 months, but It's still in service.
On this day in 1964 - April 8th - NASA's Gemini 1 was launched - it was an unmanned test flight.
The Gemini program was the bridge between NASA's Mercury program - its original ventures in manned spaceflight - and the Apollo moon program.
On this day in 1968 - April 9th - Europe's spaceport, the Centre Spatial Guyanais (CSG) or Guiana Space Centre, became operational.
The first launch was of a sounding rocket from the French Veronique series.
On this day in 1921 - April 9th - Mary Jackson was born.
Mary Jackson was NASA's first black female engineer. She began as a computer for NASA's predecessor organization, but went on to take advanced engineering classes. She worked at Langley Research Center in Hampton, Virginia, for most of her career.
On this day in 1959 - April 9th - NASA selected its first group of astronauts, known as the Mercury Seven.
They were the pioneers of the US manned space program: Scott Carpenter, Gordon Cooper, John Glenn, Gus Grissom, Wally Schirra, Alan Shepard, and Deke Slayton. None of the Mercury Seven are still alive.
On this day in 1919 - April 10th - John C. Houbolt was born.
Houbolt, an American aerospace engineer, is credited with leading the team behind the lunar orbit rendezvous (LOR) that was used to land humans on the Moon and return them to Earth. Using LOR, NASA saved time and billions of dollars by efficiently using existing rocket technology.
On this day in 1960 - April 11th - Project Ozma began.
Cornell University astronomer Frank Drake initiated this project. It was a pioneering SETI (Search for ExtraTerrestrial Intelligence) experiment that searched for signs of life in distant planetary systems by monitoring interstellar radio waves.
On this day in 1970 - April 11th - NASA's Apollo 13 Moon mission was launched.
This was the ill-fated mission that didn't make onto the Moon, but with the assistance of a lot of smart people the astronauts made it safely back to Earth.
On this day in 1984 - April 11th - the space shuttle Challenger redeployed the Solar Max satellite following their retrieval and repair of it.
On this day in 1986 - April 11th - Halley's Comet was at its closest to the Earth.
On this day in 1980 - April 11th - NASA's Viking 2 lander astrobiology mission ended.
The lander operated on the surface for 1316 days, and was turned off on April 11, 1980 when its batteries failed.
On this day in 2006 - April 11th - ESA's Venus Express was inserted into orbit around Venus.
The mission provided an enormous amount of data on the Venusian atmosphere until the European Space Agency concluded it in December 2014. In addition to helping to understand the atmosphere of Venus, it also contributed to an a general understanding of atmospheric dynamics in general, including climate change on Earth.
On this day in 1961 - April 12th - Soviet cosmonaut Yuri Gagarin became the first spaceman.Gagarin made the historic first orbit of the Earth in the Vostok 1 craft.
On this day in 1597 - April 13th - Giovanni Battista Hodierna was born.
Hodierna was a Sicilian astronomer at the court of the Duke of Montechiaro. Pre-dating Charles Messier by over a century, he compiled a sky catalog that included a number of nebulous objects that might be confused with comets.
On this day in 1629 - April 14th - Dutch scientist and mathematician Christiaan Huygens was born.
Huygens was a prominent scientist in his day, his varied contributions including the invention of the pendulum clock, and the discovery of Saturn's moon Titan. NASA named its Titan lander after him.
On this day in 1972 - April 16th - Apollo 16 was launched.
It was crewed by Commander John Young, Lunar Module Pilot Charles Duke and Command Module Pilot Ken Mattingly.
On this day in 1598 - April 17th - Italian astronomer Giovanni Riccioli was born.
Riccioli's best known for his Almagestum Novum published in 1651. It included his Moon map and over 1500 folio pages densely packed with text, tables and illustrations. The work became a standard technical reference book for astronomers all over Europe and included the names of prominent lunar features still in current use.
It's amazing to think that with all the advances in technology that we enjoy, back in ancient times the technology our ancestors had and what our ancestors accomplished. They laid the ground work for what we do today.
On this day in 2014 - April 18th - NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE) was intentionally crashed into Moon at end of its mission.
LADEE, orbiting the Moon's equator, studied the lunar exosphere and dust in the Moon's vicinity. It was crashed on the far side of the Moon to ensure that it didn't damage historically important landing sites on the near side.
On this day in 1971 - April 19th - Salyut 1 was launched.
Salyut 1 was launched by the Soviet Union, and was the first ever manned space station.
On this day in 1967 - April 20th - NASA's Surveyor 3 unmanned probe landed on the Moon.
In November 1969, Apollo 12 astronauts Charles Conrad and Alan Bean would land near the probe and remove some parts to return them to Earth.
On this day in 1858 - April 23rd - Max Planck was born.
Planck was a German theoretical physicist best known as the originator of quantum theory. His work won him the Nobel Prize in Physics in 1918. The European Space Agency (ESA) named a space observatory for him - it mapped the cosmic microwave background from 2009-2013.
On this day in 1970 - April 24th - China became the fifth nation to launch its own satellite.
On this day in 1990 - April 25th - the Hubble Space Telescope was deployed.
The STS-31 mission of the shuttle Discovery launched the telescope.
On this day in 1920 - April 26th - the Shapley-Curtis debate took place on the nature and distance of "spiral nebulae".
Even a century ago, we didn't know what the "spiral nebulae" were. Were they objects in our Milky Way galaxy and therefore comparatively close? Or were they "island universes", i.e., other galaxies, and therefore at a great distance?
On this day in 2017 - April 26th - the Cassini spacecraft made the first dive of the Grande Finale of its 13-year study of the Saturnian system.
It was the first of a series of close orbits that involved Cassini diving between Saturn and its rings. Astronomers collected data to learn more about the origins, mass, and age of Saturn's rings, as well as the mysteries of the gas giant's interior.
On this day in 2003 - April 28th - NASA's Galaxy Evolution Explorer (GALEX) was launched.
GALEX, which operated until early 2012, was an orbiting space telescope observing galaxies in ultraviolet light. Its observations provided data about how galaxies, the basic structures of our Universe, evolve and change.
On this day in 1900 - April 28th - Dutch astronomer Jan Oort was born.Oort made major contributions to the understanding of the Milky Way and was a pioneer in radio astronomy. He realized that the orbits of comets "implied there was a lot more solar system than the region occupied by the planets." The Oort cloud of comets that surrounds the Solar System was named for him.
On this day in 1906 - April 28th - Dutch-American astronomer Bart Bok was born.He's best known for his work on the structure and evolution of our Galaxy and the dark nebulae named for him. Click here to learn more about Bok globules.
On this day in 1928 - April 28th - American geologist and planetary scientist Gene Shoemaker was born.
Shoemaker was one of the founders of the study of planetary science. And along with his wife Carolyn and David Levy, he was co-discoverer of Comet Shoemaker-Levy 9 which hit Jupiter.
On this day in 2003 - April 28th - NASA's Galaxy Evolution Explorer (GALEX) was launched.
GALEX, which operated until early 2012, was an orbiting space telescope observing galaxies in ultraviolet light. Its observations provided data about how galaxies - the basic structures of our Universe - evolve and change.
On this day in 2013 - April 29th - ESA's Herschel Space Observatory mission ended.
The European Space Agency's infrared observatory was named after William Herschel, who discovered infrared radiation, and his sister and collaborator Caroline Herschel. The observatory was able to see the coldest and dustiest objects in space, but it needed liquid helium to cool its instruments. When that ran out, the mission ended.
On this day in 1949 - May 1st - Gerard Kuiper discovered Neptune's moon Nereid.Nereid was the second known moon of Neptune. It was discovered over a century after William Lassell discovered the first one, Triton.
On this day in 1682 - May 1st - the Paris Observatory was inaugurated by Louis XIV.It's one of the oldest (and the oldest still active) astronomical centres in the world.
On this day in 1996 - May 1st - Comet Hyakutake made its closest approach to Sun.
It's known as The Great Comet of 1996. its passage near the Earth was one of the closest cometary approaches of the previous 200 years.
On this day in 1989 - May 4th - the Magellan spacecraft was released by Space Shuttle mission STS-30 Atlantis, the first interplanetary mission to be so launched.
The spacecraft, often referred to as the Venus Radar Mapper, successfully mapped the surface of Venus using synthetic aperture radar which is able to penetrate the planet's thick clouds.
On this day in 2002 - May 4th - NASA launched the Aqua scientific research satellite.
It was the second major component of the Earth Observing System (EOS), and was designed to study the precipitations, evaporation and cycling of water.
On this day in 1961 - May 5th - Alan Shepard became the first American in space, making a suborbital flight in Freedom 7.Ten years later Shepard walked on the Moon as the commander of Apollo 11.
On this day in 2003 - May 9th - the Japanese mission Hayabusa ("peregrine falcon") was launched.
Hayabusa was the first mission to return a sample of material from an asteroid.
On this day in 1900 - May 9th - Cecilia Payne-Gaposchkin was born.Cecilia Payne, in her PhD thesis, was the first to propose that stars stars were composed mainly of hydrogen and helium.
On this day in 1915 - May 11th - Einstein's General Theory of Relativity was published.Einstein's theory has often been tested and has passed every test - it's changed the way we viewed the cosmos.
On this day in 2009 - May 11th - space shuttle mission STS-125 was launched.
STS-125 was the fifth and final servicing mission for the Hubble Space Telescope.
On this day in 1930 - May 12th - the Adler Planetarium opened in Chicago.
It was the first planetarium in the western hemisphere.
On this day in 1978 - May 12th - ESA's VILSPA ground station (now the European Space Astronomy Centre) in Spain was officially opened by their Majesties King Juan Carlos and Queen Sofia.
VILSPA was one of European Space Agency's original tracking stations and has been responsible for providing telemetry, tracking and command support to ESA as well as non-ESA satellites.
On this day in 2009 - May 14th - the European Space Agency (ESA) launched the Herschel Space Observatory.Launched along with the Planck Space Observatory, from 2009-2013 Herschel observed the cosmos in infrared.
On this day in 2009 - May 14th - the European Space Agency (ESA) launched the Planck Space Observatory.
Launched along with the Herschel Space Observatory, from 2009-2013 Planck made high resolution studies of the cosmic microwave background radiation left over from the very early Universe.
On this day in 1973 - May 14th - NASA launched Skylab.
It was the first US space station, and it included a workshop, a solar observatory, and several hundred life science and physical science experiments.
On this day in 1857 - May 15th - Scottish-American astronomer Williamina Fleming was born.Fleming, a computer at Harvard College Observatory, was a pioneer in the classification of stellar spectra. During the course of her career, she also discovered 10 novae, 52 nebulae, and 310 variable stars.
On this day in 1718 - May 15th - Johannes Kepler discovered the simple mathematical rule governing the orbits of the solar system's planets, now recognized as Kepler's Third Law of planetary motion.Kepler's three laws described the orbital motions of the planets in a solar system where they orbited the Sun, not the Earth.
On this day in 2011 - May 16th - STS-134 Endeavour was launched, the final space shuttle mission.
On this day in 1925 - May 16th - American astronomer Nancy Grace Ronan was born.
One of the first female executives at NASA, Ronan is known to many as the "Mother of Hubble" for her role in planning the Hubble Space Telescope.
On this day in 1974 - May 17th - NASA launched the first ever geostationary satellite.
SMS-1 (Synchronous Meteorological Satellite) was the first satellite in the first series of geostationary meteorological satellites. (A geostationary satellite is in an orbit that keeps it above the same part of the Earth all of the time.)
On this day in 1968 - May 17th - the first ESRO satellite was successfully launched.
The European Space Research Organisation (ESRO) was a precursor to the European Space Agency (ESA). ESRO-2B was the first mission controlled by teams at the European Space Operations Centre in Darmstadt, Germany. It was mainly intended to study X-ray and particle emissions from the Sun.
On this day in 1836 - May 17th - English scientist and astronomer Norman Lockyer was born.
Lockyer and French scientist Pierre Janssen independently discovered the gas helium in the light spectrum of the Sun decades before any was found on Earth.
On this day in 2009 - May 18th - the final spacewalk to service the Hubble Space Telescope took place.
Amongst other things the astronauts installed some new instruments, made repairs to two instruments, replaced old batteries, and added new gyroscopes.
On this day in 1990 - May 20th - the Hubble Space Telescope sent back its first image, that of several stars, captured with its Wide Field/Planetary Camera.
Unfortunately, they then discovered there was a flaw in the main mirror which meant fuzzy images for three years until the first shuttle servicing mission. Interestingly, the images were still much better than the ones from ground-based telescopes of the time.
On this day in 1991 - May 18th - Helen Sharman became the first Briton (and first European woman) in space.
She was launched with crew mates Anatoli Artsebarsky and Sergei Krikalev on a Soyuz spacecraft, orbiting Earth for two days before docking with the Mir space station where she performed a number of experiments.
On this day in 1990 - May 20th - the Hubble Space Telescope sent back its first image, that of several stars, captured with its Wide Field/Planetary Camera.
Unfortunately, they then discovered there was a flaw in the main mirror which meant fuzzy images for three years until the first shuttle servicing mission. Interestingly, the images were still much better than the ones from ground-based telescopes of the time.
On this day in 2010 - May 21st - the Japanese experimental aircraft IKAROS was launched.
IKAROS (Interplanetary Kite-craft Accelerated by Radiation Of the Sun) is the first spacecraft to successfully demonstrate solar sail technology in interplanetary space.
On this day in 2008 - May 25th - NASA's Phoenix lander landed on Mars.
Phoenix was expected to spend 90 Martian sols searching for environments suitable for microbial life. It carried out its mission for 157 Martian sols. (A sol is a Martian day - it's about 40 minutes longer than an Earth day).
On this day in 1961 - May 25th - President John F. Kennedy challenged the USA to "commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to the Earth."
Sadly, Kennedy didn't live to see it happen.
On this day in 1983 - May 26th - ESA's X-ray observatory, Exosat, was launched.
Exosat was the first European Space Agency mission to study the Universe at X-ray wavelengths, and one of the first unmanned satellites to feature an onboard computer. The spacecraft was operational from May 1983 to April 1986.
On this day in 1951 - May 26th - physicist, engineer, educator and astronaut Sally Ride was born.
Ride was the first American woman in space, her first flight almost twenty years to the day after cosmonaut Valentina Tereshkova became the first woman in space.
On this day in 1931 - May 27th - Swiss physicist and explorer Auguste Piccard, with Paul Kipfer, became the first persons to travel into the stratosphere.
They reached a record altitude in a balloon with a pressurized aluminum gondola designed by Piccard. Piccard wanted to measure the activity of cosmic rays and investigate Einstein's theory of relativity.
On this day in 1919 - May 29th - Einstein's General Theory of Relativity was tested during a total solar eclipse.By comparing the apparent distance between stars in the constellation Taurus, with and without the Sun between them, British astrophysicist Arthur Eddington confirmed the theoretical predictions about gravitational lensing.
On this day in 1794 - May 29th - German astronomer Johann Heinrich von Mädler was born.
Von Mädler, along with Wilhelm Beer, published Mappa Selenographica. It was the most complete map of the Moon at that time, and it remained unsurpassed for over forty years.
On this day in 1963 - May 30th - English chemist, astronaut and science communicator, Helen Sharman, was born.
Chosen to train as a cosmonaut, Sharman was the first Briton in space and the first woman to visit the Mir space station.
On this day in 1934 - May 30th - cosmonaut Alexi Leonov was born.
Among Leonov's many accomplishments, he was the first person to carry out a spacewalk.
On this day in 1975 - May 30th - nine countries signed the convention to establish the European Space Agency (ESA).
The convention came into force on 30 October 1980 with the deposit of the last instrument of ratification.
On this day in 1959 - May 30th - Claudia Joan Alexander was born.
Alexander, a geophysicist and planetary scientist, was the last project manager of NASA's Galileo mission to Jupiter and until her death was the project manager and scientist of NASA's role in the European Rosetta mission.
On this day in 1858 - June 2nd - Giovanni Battista Donati first observed the comet that bears his name.
Comet Donati, formally designated C/1858 L1 and 1858 VI, was one of the most brilliant comets of the 19th century. It inspired artists and poets and was also the first comet to be photographed, though the photograph has apparently been lost.
On this day in 1930 - June 2nd - Apollo astronaut Charles "Pete" Conrad Jr. was born.
Conrad was the commander of the Apollo 12 mission and the third person to walk on the Moon.
On this day in 2003 - June 2nd - ESA launched Mars Express and Beagle 2.Mars Express is still an operational orbiter. The British lander Beagle 2 was damaged as it landed on Mars and never became operational.
On this day in 1977 - June 2nd - 14 delegates from nations around the world plus the UN Secretary-General recorded greetings for the Voyager space probes' golden record.Voyagers 1 and 2 were launched a month apart later in the year. Decades later Voyager 1 became the first probe to cross the heliopause into interstellar space.
On this day in 1955 - June 2nd - the Baikonur Cosmodrome in Kazakhstan became operational and is still the world's largest space launch facility.It was from here that the first satellite to orbit the Earth was launched, and that Yuri Gagarin, the first man to orbit the Earth, was launched into space.
On this day in 1948 - June 3rd - the 200-inch Hale telescope was dedicated at Palomar Observatory in California.The telescope was a marvel of design and precision engineering and the largest in the world for several decades.
On this day in 2000 - June 4th - the Compton Gamma Ray Observatory reentered the atmosphere.
The observatory, part of NASA's Great Observatories series, detected high energy photons. It reentered the atmosphere in a controlled deorbit.
On this day in 1819 - June 5th - British mathematician and astronomer John Couch Adams was born.His most famous achievement was predicting the existence and position of Neptune, using only mathematics. But Urbain LeVerrier had independently made the calculations and the planet was discovered using LeVerrier's calculations. (Who discovered Neptune?)
On this day in 1971 - June 6th - Soyuz 11 was launched with the first crew to occupy the Salyut 1 space station.
Salyut 1 was the very first space station - it was launched into low earth orbit by the Soviet Union in April 1971.
On this day in 1971 - June 6th - Soyuz 11 was launched with the first crew to occupy the Salyut 1 space station.
Salyut 1 was the very first space station - it was launched into low earth orbit by the Soviet Union in April 1971.
On this day in 1992 - June 7th - the Extreme Ultraviolet Explorer (EUVE) was launched.
This NASA space telescope was the first one designed especially for the short-wave ultraviolet range. It went on to compile an all-sky survey of 801 astronomical targets.
On this day in 1625 - June 8th - Italian-French astronomer Giovanni Domenico (Jean-Dominique) Cassini was born.Cassini was one of the most important astronomers of the 17-18th centuries, and was the first of four Cassinis to direct the Paris Observatory. The NASA/ESA/ASI Cassini-Huygens mission to Saturn bore his name because of his study of Saturn, which included the discovery of four of Saturn's moons.
On this day in 1812 - June 9th - German astronomer Johann Gottfried Galle was born.Galle is best known for his being the first person to see the planet Neptune, knowing what he was seeing. This followed his search for the planet using the calculations Urbain Le Verrier had sent him. (Who discovered Neptune?)
On this day in 1975 - June 9th - the Soviet Union launched the Venera 9 mission.
It consisted of an orbiter and a lander. The orbiter was the first spacecraft to orbit Venus, while the lander was the first to return images from the surface of another planet.
On this day in 2003 - June 10th - NASA's Mars rover Spirit was launched.The original plan was for a three-month mission, but the mission wasn't finally terminated until May 2011
On this day in 1985 - June 11th - the descent module of the Soviet Vega 1 arrived on Venus.
After releasing the descent module, the probe Vega 1 got a gravitational assist from Venus and continued its journey to intercept Comet Halley.
On this day in 1967 - June 12th - the Soviet Union launched the Venera 4 mission to Venus.
Venera 4 was the first probe to successfully perform in-place analysis of the environment of another planet. It may also have been the first probe to land safely on another planet, since the fate of its predecessor Venera 3 was uncertain.
On this day in 1831 - June 13th - Scottish scientist James Clerk Maxwell was born.
Maxwell showed that electricity, magnetism, and light are all aspects of the same phenomenon, electromagnetism.
On this day in 1611 - June 13th - the first documented report in Europe on the phenomenon of sunspots was published.
Narration on Spots Observed on the Sun and their Apparent Rotation with the Sun was the work of Frisian/German astronomer Johannes Fabricius.
On this day in 2010 - June 13th - the Japanese spacecraft Hayabusa ("Peregrine Falcon") returned the first ever samples from an asteroid.
Hayabusa studied asteroid 25143 Itokawa from orbit and then landed on the asteroid to collect small grains of material.
On this day in 1983 - June 13th - Pioneer 10 crossed the orbit of Neptune, our outermost planet.
Pioneer 10 was the first human-made object to leave the proximity of the major planets of the Solar System.
On this day in 1983 - June 13th - Pioneer 10 crossed the orbit of Neptune, our outermost planet.
Pioneer 10 was the first human-made object to leave the proximity of the major planets of the Solar System.
On this day in 1963 - June 16th - Valentina Tereshkova in Vostok 6 became the first woman in space.With a single flight, she logged more flight time than the combined times of all American astronauts who had flown before that date. She's the only woman ever to make a solo space flight.
On this day in 1714 - June 17th - French astronomer and cartographer Caesar-François Cassini de Thury was born.
He was the grandson of Jean Dominique Cassini - after whom the Cassini mission to Saturn was named - and the third Cassini to be the director of the Paris Observatory.
On this day in 1799 - June 18th - English merchant and astronomer William Lassell was born.
Lassell was known for his improvements to the reflecting telescope and his discoveries, e.g., two of the moons of Neptune.
On this day in 1983 - June 18th - physicist and astronaut Sally Ride became the first American woman in space.Ride was a crew member of STS-7 Challenger which was launched 2 days after the 20th anniversary of Valentina Tereshkova's space flight.
On this day in 2009 - June 18th - NASA's Lunar Reconnaissance Orbiter (LRO) and the Lunar Crater Observation and Sensing Satellite (LCROSS) were launched.
The LCROSS mission confirmed the presence of water in a shadowed crater on the Moon. LRO is still mapping the Moon.
On this day in 2004 - June 21st - SpaceShipOne was launched.
It was the first privately-funded human space flight.
On this day in 1710 - June 21st - Scottish telescope maker and astronomer James Short was born.
Short produced the first telescopes with nearly distortionless mirrors, and was the principal British collator and computer of the 'Transit of Venus' observations made throughout the world on 6 June 1761.
On this day in 1667 - June 21st - the meridian line of the Paris Observatory was engraved.It was decided that the observatory should be built so that the Paris meridian passed through the center of the building, dividing it into two symmetrical parts. Built by order of King Louis XIV, the Paris Observatory was the first national observatory.
On this day in 1675 - June 22nd - the Royal Observatory Greenwich was founded.The Prime Meridian (0 degrees of longitude) goes through Greenwich.
On this day in 1999 - June 24th - NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) was launched.
Operated by the Johns Hopkins University Applied Physics Laboratory, for eight years, it detected light in a part of the electromagnetic spectrum which is mostly unobservable by other telescopes.
On this day in 1915 - June 24th - British mathematician and astronomer Sir Fred Hoyle was born.
Hoyle was the first to formulate a theory that explained the creation of chemical elements by nuclear fusion reactions in stars.
On this day in 1894 - June 25th - German physicist and engineer Hermann Oberth was born.
Oberth is considered one of the founding fathers of rocketry and astronautics.
On this day in 2013 - June 27th - NASA's IRIS (Interface Region Imaging Spectrograph) was launched.
IRIS was deisgned to investigate the physical conditions of the solar limb, particularly the chromosphere of the Sun.
On this day in 1914 - June 26th - American theoretical physicist and astronomer Lyman Spitzer, Jr. was born.
His major contributions to astronomy included his studies of star formation and the interstellar medium. The Spitzer Space Telescope is named in his honor.
On this day in 2013 - June 27th - NASA's IRIS (Interface Region Imaging Spectrograph) was launched.
IRIS was designed to investigate the physical conditions of the solar limb, particularly the chromosphere of the Sun.
On this day in 1912 - June 28th - Australian radio astronomer Ruby Payne-Scott was born.
Payne-Scott was a pioneer in radiophysics and radio astronomy, and was the first female radio astronomer.
On this day in 1995 - June 28th - the first docking between the Soviet space station Mir and the American Space Shuttle took place.
Daniel Goldin, chief of NASA, called it the beginning of “a new era of friendship and cooperation” between the U.S. and Russia. It helped to pave the way for the creation of the International Space Station.
On this day in 1868 - June 29th - George Ellery Hale, American solar astronomer, was born.
Hale was a key figure in the realization of three major telescopes, the 40-inch refractor at Yerkes Observatory, 60-inch Hale and 100-inch Hooker reflectors at Mount Wilson Observatory, and the 200-inch Hale reflector at Palomar Observatory
On this day in 2001 - June 30th - the Wilkinson Microwave Anistotropy Probe (WMAP) was launched.
This spacecraft operated from 2001 to 2010. Across the sky it measured tiny temperature differences in the cosmic microwave background (CMB) - the radiant heat left over from the Big Bang.
On this day in 1990 - June 30th - the joint ESA/NASA Ulysses mission came to an end after 18 years in service.
Ulysses was the first ever spacecraft to explore space above and below the Sun's poles. When it was launched it had a nominal lifetime of five years.
On this day in 1908 - June 30th - an asteroid impact leveled hundreds of miles of Siberian forest around Tunguska.
The event is classified as an impact even, but is thought to have been caused by a meteoroid exploding above ground. No impact crater has ever been found.
On this day in 1917 - July 1st - the 100" mirror for the Hooker telescope arrived at Mt Wilson Observatory.
This telescope was the biggest in the world for three decades. Edwin Hubble calculated the distance to Andromeda from a Cepheid variable he discovered there with the telescope. It showed Andromeda was a separate galaxy. Hubble and Milton Humason also observed the redshifts of a number of galaxies and found that they were moving away from us.
On this day in 1985 - July 2nd - the European Space Agency (ESA) launched the Giotto probe to study Halley's Comet.
Giotto would be the first spacecraft ever to make close up observations of a comet.
On this day in 1935 - July 3rd - geologist and Apollo 17 astronaut Harrison Schmitt was born.
Schmitt is the only scientist to have gone to the Moon.
On this day in 2005 - July 4th - NASA's Deep Impact probe collided with comet Tempel 1.
The Deep Impact mission was designed to study the interior composition of the comet Tempel 1 (9P/Tempel) by releasing an impactor into it.
On this day in 1054 - July 4th - Chinese astronomers observed the supernova explosion that created the Crab Nebula (Messier 1) in the constellation Taurus.The supernova would have occurred some 6500 years before it was observed on Earth, since it's around 6500 light years away.
On this day in 1997 - July 4th - NASA's Mars Pathfinder landed on Mars.
The robotic spacecraft consisted of a lander, renamed the Carl Sagan Memorial Station, and a wheeled robotic Mars rover named Sojourner. It was the first successful Mars rover.
On this day in 1868 - July 4th - American astronomer Henrietta Swan Leavitt was born.Her discovery of the relationship between the period and the luminosity of Cepheid variable stars made possible Edwin Hubble's work on galactic distances.
On this day in 2016 - July 5th - NASA's Juno mission went into polar orbit around Jupiter.
Juno's mission is to explore Jupiter, seeking to unlock secrets of the giant planet and our solar system.
On this day in 1687 - July 5th - Edmond Halley published the Principia of Isaac Newton.Philosophiæ Naturalis Principia Mathematica (Latin for 'Mathematical Principles of Natural Philosophy') states Newton's laws of motion and of universal gravitation. It's regarded as one of the most important works in the history of science.
On this day in 2003 - July 7th - NASA's Mars rover Opportunity was launched for a three-month mission.
Opportunity was still at work on the red planet until the summer of 2018 when it was unable to recover after a massive planet wide dust storm.
On this day in 2011 - July 8th - STS-135 Atlantis was launched, the final space shuttle mission.
By the end of that mission, Atlantis had orbited the Earth a total of 4,848 times, traveling nearly 126,000,000 mi (203,000,000 km) or more than 525 times the distance from the Earth to the Moon.
At one time we all watched and kept up with all of NASA's doings. I miss reading about the accomplishments.
On this day in 1962 - July 10th - Telstar 1 was launched.It was the beginning of a revolution in global communications.
On this day in 1992 - July 10th - ESA's Giotto spacecraft flew past comet Grigg-Skjellerup.
Having successfully returned images and data from Halley's Comet in 1986, the flyby of Grigg-Skjellerup was the completion of Giotto's mission.
On this day in 1732 - July 11th - French astronomer Jérôme Lalande was born.
He held the chair of astronomy in the Collège de France in for nearly half a century and a number of his pupils became distinguished astronomers. As well as being an observer, Lalande also gave popular lectures and wrote about astronomy.
On this day in 1979 - July 11th - NASA's Skylab re-entered the atmosphere.Skylab had orbited for seven years and provided valuable data for human space flight.
On this day in 2000 - July 12th - the Zvezda Service Module was launched to the International Space Station (ISS).
It was the third module launched to the station, and provides all of the station's life support systems, as well as living quarters for two crew members. It's the structural and functional center of the Russian Orbital Segment.
On this day in 2019 - July 13th - the Russian Spektr RG X-ray Observatory launched.
The satellite is a Russian–German high-energy astrophysics space observatory.
On this day in 2015 - July 14th - NASA's New Horizons mission made a historic fly-by of Pluto and its moons.
The data that came home has revolutionized our conception of the dwarf planet.
On this day in 1965 - July 15th - NASA's Mariner 4 completed the first successful flyby of the planet Mars, returning the first close-up pictures of the Martian surface.
The images were the first images of another planet ever returned from deep space.
On this day in 1943 - July 15th - Northern Irish astrophysicist Jocelyn Bell Burnell was born.As a graduate student she first noted what turned out to be rotating neutron stars. Until then neutron stars were only theoretically an endpoint of the evolution of massive stars.
On this day in 1975 - July 15th - the Apollo-Soyuz Test Project was launched from Baikonur Cosmodrome and the Kennedy Space Center.
This was the first joint U.S.-Soviet space flight, a symbol of detente between the superpowers - it involved the docking of an Apollo Command/Service Module with the Soviet Soyuz.
On this day in 1969 - July 16th - Apollo 11 was launched.
Neil Armstrong, Buzz Aldrin and Michael Collins set off for the Moon. They weren't the first to visit our satellite, but Armstrong and Aldrin would be the first to land on it.
On this day in 2011 - July 16th - NASA's Dawn spacecraft entered orbit around the asteroid Vesta.
The spacecraft later moved on to dwarf planet Ceres where it was active until November 2018.
On this day in 2000 - July 16th - the first pair of the ESA Cluster satellite fleet lifted off on a Russian Soyuz rocket from Baikonur, Kazakhstan.
Cluster is a set of four spacecraft flying in formation around Earth, relaying in three dimensions the most detailed-ever information about the effects of the solar wind on our planet.
On this day in 1894 - July 17th - Belgian priest, astronomer and physicist Georges Lemaître was born.
Lemaître made the first definitive formulation of the idea of an expanding universe, and what was to become known as the Big Bang theory of the origin of the universe.
On this day in 1850 - July 17th - John Adams Whipple took the first stellar photograph.
The photo was of the star Vega, taken at the Harvard College Observatory in the USA.
On this day in 1921 - July 18th - NASA astronaut John Glenn was born.
Glenn was the first American to orbit the Earth. He had a distinguished military career before becoming an astronaut, and was a US senator afterwards. In 1998 he took part in a space shuttle mission, making him oldest person ever to go into space.
On this day in 1846 - July 19th - Edward Pickering was born.Pickering was the director of Harvard College Observatory who hired women assistants (computers), and who modernized the observatory's work in astronomy by the use of photography.
On this day in 1969 - July 20th - Apollo 11 astronauts became the first humans to set foot on another world.
Neil Armstrong, followed by Buzz Aldrin, stepped out of their lander and walked on the Moon, taking photographs, collecting rocks and setting up experiments.
On this day in 1976 - July 20th - NASA's Viking 1 became the first spacecraft to land successfully on Mars and perform its mission.
Part of its mission was a biology experiment whose purpose was to look for evidence of life.
On this day in 1620 - July 21st - French astronomer Jean Picard was born.
Picard collaborated and corresponded with many fellow scientists, including Isaac Newton, Christiaan Huygens, Ole Rømer, and Giovanni Cassini, among others. He was a founding member of the French Academy of Sciences.
On this day in 1784 - July 22nd - German astronomer and mathematician Friedrich Bessel was born.
Bessel was the first to publish a reliable value for the distance from the Sun to another star using parallax.
On this day in 1928 - July 23rd - American astronomer Vera Rubin was born.
Rubin's pioneering work on galaxy rotation rates uncovered a discrepancy between the predictions and the observations. This was early evidence for the existence of dark matter.
On this day in 1999 - July 23rd - NASA's Chandra X-ray Observatory was deployed by STS-93 Columbia.
Columbia was under the command of Eileen Collins, the first woman commander of s space shuttle mission.
On this day in 1972 - July 23rd - the US launched Landsat 1.
The near-polar orbiting spacecraft served as a stabilized, Earth-oriented platform for obtaining information on Earth resources of all kinds, meteorology, pollution, etc. Over the lifetime of the satellite it provided around 300,000 images.
On this day in 1950 - July 24th - the first rocket was launched from Cape Canaveral, Florida.
Cape Canaveral - which for a time was called Cape Kennedy - became the launch site for the manned space program. Until May 30, 2020, the USA could only put astronauts into space via Russian launches.
On this day in 1969 - July 24th - the crew of Apollo 11 returned safely to Earth.
President John F. Kennedy's goal "of landing a man on the moon and returning him safely to the earth" had been achieved "before this decade is out", though he didn't live to see it.
On this day in 1975 - July 24th - the last Apollo crew returned to Earth after docking and working with a Russian Soyuz crew.
The end of the Apollo Soyuz mission was the final flight of the Apollo program and the last US splashdown.
On this day in 2009 - July 24th - the Gran Telescopio Canarias (GranTeCan or GTC) was dedicated.
Located on La Palma in the Canary Islands of Spain, it's the world's largest single-aperture optical telescope.
On this day in 1982 - July 25th - Svetlana Savitskaya became the first woman to walk in space.
The Soviet cosmonaut was the first woman to go into space after Valentina Tereshkova's initial flight nineteen years earlier.
On this day in 2000 - July 25th - the Zvezda Service Module docked with International Space Station.
It was the first fully Russian contribution to the International Space Station and served as the early cornerstone for the first human habitation of the station.
On this day in 1971 - July 26th - Apollo 15 was launched.
This would be the first mission to use the lunar rover to explore the Moon.
On this day in 1609 - July 26th - English astronomer and mathematician Thomas Harriot looked at the Moon through a telescope, and made a dated sketch of what he saw.It's the oldest known drawing of a telescopic body - it was made nearly four months before Galileo's first drawing.
On this day in 1801 - July 27th - English mathematician and Astronomer Royal Sir George Biddell Airy was born.He's known for his work on planetary orbits, measuring the mean density of the Earth and, in his role as Astronomer Royal, for establishing the meridian in Greenwich in London that became the prime meridian of the world.
On this day in 1638 - July 28th - the English polymath Robert Hooke, often called "England's Leonardo", was born.Hooke contributed to astronomy, geology, structural engineering, chemistry and physics, helped rebuild London after the Great Fire, and was a renowned experimenter, inventor, musician and artist.
On this day in 1851 - July 28th - the first successful photographic image of a solar eclipse, showing the Sun's corona, was made.
The eclipse image was a daguerrotype made by J. Berkowski at the Royal Observatory in Königsberg, Germany (now Kaliningrad, Russia).
On this day in 1919 - July 28th - The International Astronomical Union (IAU) was founded.
Its mission is to promote and safeguard the science of astronomy in all its aspects, including research, communication, education and development, through international cooperation.
On this day in 1999 - July 31st - NASA's Lunar Prospector mission ended.
The probe investigated the Moon from low polar orbit, among other things mapping surface composition and possible polar ice deposits. The orbiter was deliberately crashed into a crater near the lunar south pole in the hope that it would create a plume in which water could be detected. (It didn't.)
On this day in 1971 - July 31st - the first vehicle was driven on the Moon.
By using the lunar rover, astronauts Dave Scott and Jim Irwin were able to explore more widely than anyone had before.
On this day in 1818 - August 1st - American astronomer Maria Mitchell was born.She was the first American woman to discover a comet, the first to be a college professor, and the first woman to be elected to scientific societies in the USA.
On this day in 1786 - August 1st - German astronomer living in England, Caroline Herschel, discovered her first comet.In the years from 1786 to 1797 she discovered eight comets.
On this day in 2004 - August 3rd - NASA launched the MESSENGER spacecraft to Mercury.
MESSENGER's mission was to study Mercury's chemical composition, geology, and magnetic field.
On this day in 2007 - August 4th - the Phoenix Mars Lander was launched.
The program was a partnership of universities in several countries directed by NASA's Jet Propulsion Laboratory. Its purpose was to look for environments suitable for microbial life on Mars.
On this day in 2011 - August 5th - NASA's Juno spacecraft was launched to Jupiter.
Juno is currently getting amazing close-up pictures of Jupiter.
On this day in 1930 - August 5th - Neil Armstrong, Apollo 11 astronaut and the first human to set foot on another world, was born.
On this day in 2014 - August 6th - ESA's Rosetta became the first spacecraft to rendezvous with a comet.Rosetta finally met up with Comet 67P/Churyumov-Gerasimenko after a decade-long journey chasing it.
On this day in 1961 - August 6th - the Soviet Vostok 2 was launched, the first full day mission.
Cosmonaut Gherman Titov became the second man in space and the first person to sleep in space.
On this day in 2012 - August 6th - the Mars Science Laboratory rover Curiosity landed on Mars.
Curiosity, currently the only active Martian rover, continues to carry out the mission of searching for signs of habitable environments, past and present, on the red planet.
On this day in 1989 - August 8th - the European Space Agency (ESA) satellite Hipparcos was launched.
It was the first space experiment devoted to the accurate measurement of the positions of celestial objects in the sky. It operated until 1993.
On this day in 2001 - August 8th - NASA's Genesis spacecraft was launched.
Genesis was a sample-return probe designed to collect a sample of solar wind and return it to Earth for analysis.
On this day in 1576 - August 8th - Tycho Brahe laid the cornerstone for Uraniborg.
Uraniborg, built on the island of Hven between Denmark and Sweden, was a custom-built observatory and research center, the most advanced that had ever been seen at that time.
On this day in 1948 - August 8th - Soviet cosmonaut Svetlana Savitskaya was born.
She was the second woman in space and the first to carry out a spacewalk.
On this day in 2000 - August 9th - the European Space Agency (ESA) launched the second pair of Cluster satellites.
They completed the four-satellite constellation of the Cluster II mission, which is still making the most detailed investigation yet of how the Sun and Earth interact.
On this day in 1675 - August 10th - the first Astronomer Royal John Flamsteed laid the cornerstone for the Royal Observatory in Greenwich.
By the end of the 19th century most of the world's shipping was using navigation charts based on the Prime Meridian at Greenwich.
On this day in 1966 - August 10th - NASA's Lunar Orbiter 1 was launched.
It was the first American spacecraft to orbit the Moon.
On this day in 1990 - August 10th - NASA's Magellan spacecraft entered orbit around Venus to begin radar mapping of the surface.
It had been launched on May 4, 1989, the first interplanetary mission to be launched from the Space Shuttle.
On this day in 1919 - August 12th - Anglo-American astronomer Margaret Burbidge (nee Peachey) was born in Cheshire, England.
She made notable contributions to the theory of quasars, to measurements of the rotation and masses of galaxies, an was the lead author on a groundbreaking paper describing how chemical elements are formed in the depths of stars through nuclear fusion. She was the first woman director of the Royal Greenwich Observatory and the first woman to be president of the American Astronomical Society.
On this day in 1877 - August 12th - American astronomer Asaph Hall discovered Deimos, moon of Mars.Moons had long since been found for all the other planets beyond Earth, so Hall's discoveries were quite a sensation.
On this day in 2005 - August 12th - NASA's Mars Reconnaissance Orbiter (MRO) was launched.
Since 2006, MRO has been conducting reconnaissance and exploration of Mars from orbit.
On this day in 2018 - August 12th - NASA's Parker Solar Probe (PSP) was launched.
Its mission is to observe and probe the Sun's outer corona. At closest approach, Parker Solar Probe will be hurtling around the Sun at approximately 430,000 miles per hour! That's fast enough to get from Philadelphia to Washington, D.C., in one second.
On this day in 1970 - August 17th - the Soviet probe Venera 7 was launched.
When it landed on the Venusian surface, it became the first spacecraft both to land on another planet and to transmit data from there back to Earth.
On this day in 2006 - August 17th - Voyager 1 was the first spacecraft to be 100 AU from the Earth.It went on to become the first spacecraft to leave the heliosphere, the bubble that the solar wind makes in space.
On this day in 1936 - August 17th Margaret Hamilton was born.Hamilton was the lead developer for the Apollo flight software, and her rigorous systems approach was essential to its success.
On this day in 1877 - August 18th - American astronomer Asaph Hall discovered Phobos, a second moon of Mars.Moons had long since been found for all the other planets beyond Earth, so Hall's discoveries were quite a sensation.
On this day in 1868 - August 18th - during a total solar eclipse French astronomer Pierre Janssen observed an unknown line in the spectrum of the Sun, which turned out to be a new element, helium.
The same result was found independently by British astronomer Norman Lockyer, and both Janssen's and Lockyer's communications were presented to the French Academy of Sciences on October 26, 1868.
On this day in 1646 - August 19th - English astronomer John Flamsteed was born.Flamsteed was the first Astronomer Royal at the Royal Observatory Greenwich, and his star atlas was the standard for a nearly a century.
On this day in 1891 - August 19th - American astronomer Milton Humason was born.
Humason's careful measurement of the radial velocities of several hundred galaxies underpinned the work of Edwin Hubble.
On this day in 1982 - August 19th - Soviet cosmonaut Svetlana Savitskaya became the second woman to go into space.
Her flight on the Soyuz T-7 took place 19 years after that of the first woman in space Valentina Tereshkova.
I really don't have a desire to travel to outer space. I guess a quick trip to see our Earth from afar but not to spend much time there.
Angie, I agree. And overall I'd rather be on the Earth looking up rather than the other way around.
On this day in 1977 - August 20th - NASA's Voyager 2 was launched.It visited all four of the Solar System's gas giants and is the only spacecraft to have visited either Uranus or Neptune. In November 2018 it crossed into interstellar space.
After I read this I came on an article about space hotels coming in the next decade or so.
Angie, I agree. And overall I'd rather be on the Earth look up rather than the other way around.
On this day in 1975 - August 20th - NASA's Viking 1 was launched.
Viking 1 was the first of two spacecraft (along with Viking 2) sent to Mars as part of NASA's Viking program. A year after its launch it became the first spacecraft to land successfully on Mars and perform its mission.
On this day in 1976 - August 22nd - The Soviet Luna 24 mission returned soil samples from the Moon.
These samples were different from the previous sample return missions because they were collected from 2.5 meters below the surface.
On this day in 1966 - August 23rd - NASA's Lunar Orbiter 1 took the first picture of the Earth ever taken from the Moon.The spacecraft's primary mission was to photograph smooth areas of the lunar surface for selection and verification of safe landing sites for the Surveyor and Apollo missions.
On this day in 2006 - August 24th - a vote by the General Assembly of the International Astronomical Union changed the classification of Pluto from planet to the new category dwarf planet.Pluto's small size - smaller than the Moon - and highly elliptical tilted orbit which overlaps with that of Neptune were two of the main reasons.
On this day in 2003 - August 25th - NASA's Spitzer Space Telescope was launched.
Spitzer was an infrared telescope whose mission ended on January 30, 2020.
On this day in 1609 - August 25th - Galileo Galilei made the first recorded demonstration of a telescope.
He demonstrated one he had made to Venetian lawmakers - it had a magnification about 8 or 9.
On this day in 1609 - August 25th - Galileo Galilei made the first recorded demonstration of a telescope.
He demonstrated one he had made to Venetian lawmakers - it had a magnification about 8 or 9.
On this day in 1989 - August 25th - NASA's Voyager 2 spacecraft flew past Neptune.Voyager 2 is still the only spacecraft to have visited Neptune.
On this day in 1918 - August 26th - Katherine Coleman Goble Johnson was born.
Katherine Johnson was an African-American mathematician whose calculations of orbital mechanics as a NASA employee were important for the success of the first and subsequent U.S. manned spaceflights.
On this day in 1962 - August 27th - NASA's Mariner 2 spacecraft was launched.
This space probe to Venus was the first robotic space probe to conduct a successful planetary encounter.
On this day in 1789 - August 28th - William Herschel discovered Enceladus, moon of Saturn.
On this day in 1993 - August 28th - NASA's Galileo spacecraft did a flyby of asteroid Ida.
Galileo was an unmanned spacecraft that probed the planet Jupiter and its moons, as well as some other Solar System objects on its way to the Jovian system.
On this day in 1745 - August 30th - German astronomer Johann Hieronymus Schröter was born.
He built his own observatory and devoted himself primarily to solar and planetary astronomy. His two volumes on lunar topography reached levels of detail that were to remain unsurpassed for many years.
On this day in 1913 - August 31st - English radio astronomer Bernard Lovell was born.Lovell was a pioneer of radio astronomy and founded the Jodrell Bank Observatory in Cheshire, England in 1945. When the telescope was built there - later named the Lovell Telescope - it was for many years the largest steerable radio telescope in the world.
On this day in 1979 - September 1st - NASA's probe Pioneer 11 became the first spacecraft to fly past Saturn.
Pioneer 11 is now over 126 times farther away from the Sun than Earth is - its final signal was received in 2003.
On this day in 1979 - September 3rd - NASA's Viking 2 landed on Mars.
Viking 2 was one half of NASA's first astrobiology mission to the red planet.
On this day in 1970 - September 3rd - NASA cancelled the last two planned lunar landings.
Apollos 18 and 19 were officially cancelled following cuts to NASA's budget for 1971. The Cold War political point had been made and the public had also lost interest after the excitement of Apollo 11.
On this day in 2006 - September 3rd - ESA's SMART-1 spacecraft ended its mission when it was deliberately crashed into the Moon's surface.
SMART-1 spent 16 months testing testing innovative and miniaturised space technologies. It also produced detailed maps of the Moon's chemical make-up, to help refine theories about its birth.
On this day in 2008 - September 5th - ESA's Rosetta Mission made its closest approach to asteroid (2867) Steins at a distance of 800 km.This was Rosetta's first encounter with an asteroid and it produced data about the asteroid that couldn't have been obtained from Earth.
On this day in 1977 - September 5th - NASA launched the Voyager 1 spacecraft.Voyager 1 is now over 150 AU from Earth - that's 150 times farther away from us than the distance from the Earth to the Sun. It's in interstellar space.
On this day in 1908 - September 5th - Edoardo Amaldi, Italian cosmic-ray physicist, was born.
The reconstruction of the Italian scientific environment after World War II was due almost entirely to Amaldi, and he was one of the founding fathers of the European Space Research Organisation which would later become the European Space Agency (ESA)
On this day in 2013 - September 7th - NASA launched the Lunar Atmosphere and Dust Environment Explorer (LADEE).
The orbiter explored the lunar exosphere and dust in the Moon's vicinity.
On this day in 2004 - September 8th - NASA's Genesis probe that had collected bits of solar wind, crash-landed when it returned to Earth.
Some samples were salvaged, as some of the contamination could be dealt with. The mission's major science objectives were achieved.
On this day in 2016 - September 8th - NASA launched OSIRIS-REx, an asteroid study and sample return mission.
The spacecraft arrived at asteroid Bennu in December 2018, has carried out detailed reconnaissance of the asteroid, and has been preparing for its first sample collection, which is scheduled for October 2020.
On this day in 1789 - September 9th - American astronomer William Cranch Bond was born.
Bond was the first director of the Harvard College Observatory, and a pioneer of astrophotography.
On this day in 1975 - September 9th - NASA launched the Viking 2 mission.
It was an orbiter and lander like Viking 1, the other half of the first astrobiology mission to Mars.
On this day in 1892 - September 9th - American astronomer E.E. Barnard discovered Jupiter's moon Amalthea.
On this day in 2011 - September 10th - NASA launched the two small spacecraft GRAIL A (Ebb) and GRAIL B (Flow).
The Gravity Recovery and Interior Laboratory (GRAIL) mapped the gravitational field of the Moon in unprecedented detail.
On this day in 1857 - September 10th - American astronomer James Keeler was born.
Keeler was the director of the University of Pittsburgh's Allegheny Observatory in 1891, and later Lick Observatory in California. He was known for his studies of the rings of Saturn and for expanding astronomers' understanding of nebulae through an extended series of photographs using a large telescope.
On this day in 1877 - September 11th - English astrophysicist and mathematician James Jeans was born.
Jeans made major contributions to the early understanding of stellar radiation and stellar evolution.
On this day in 1985 - September 11th - the International Cometary Explorer (ICE) became the first spacecraft to make a flyby of a comet.
It passed through the plasma tail of comet Giacobini-Zinner within about 7,800 km (4,800 mi) of the nucleus.
On this day in 1997 - September 11th -NASA's Mars Global Surveyor arrived at Mars.
It was a global mapping mission that formed part of the larger Mars Exploration Program. NASA officially ended the mission in January 2007 following an irreparable communications failure.
On this day in 1717 - September 11th - Swedish astronomer Pehr Wilhelm Wargentin was born.
He was the first director of the Stockholm Observatory, and is probably best remembered today for his extensive study and observation of Jupiter’s satellites.
On this day in 1959 - September 12th - the Soviet spacecraft Luna 2 was launched to the Moon.
The following day Luna 2 became the first human object to land on another celestial body.
On this day in 1970 - September 12th - the Soviet spacecraft Luna 16 was launched.
It was the first robotic probe to land on the Moon and return a sample of lunar soil to Earth.
On this day in 1915 - September 14th - John Lowry Dobson was born.
Dobson was a keen amateur astronomer and popularizer of astronomy. He designed and promoted a quality telescope that could be made using inexpensive, readily available materials. The Dobsonian telescope meant that amateur astronomers could afford a portable instrument of a size and aperture that would otherwise be beyond their means.
On this day in 1968 - September 15th - the Soviet spacecraft Zond 5 was launched.
It was the first spacecraft to travel to the Moon with living creatures on board. It circled the Moon and returned safely to Earth with its passengers, including two tortoises.
On this day in 2017 - September 15th - the NASA/ESA Cassini mission ended with planned entry into Saturn's atmosphere.The Cassini spacecraft had spent over 13 years studying Saturn and its moons and rings.
On this day in 1848 - September 16th - Saturn's moon Hyperion was discovered.American astronomers William and George Bond, and English astronomer William Lassell independently discovered the moon.
On this day in 1789 - September 17th - William Herschel discovered Saturn's moon Mimas.The huge crater in the leading hemisphere of Mimas is named Herschel in honor of the moon's discoverer.
On this day in 1857 - September 17th - Russian rocket scientist Konstantin Tsiolkovsky was born.Tsiolkovsky is considered one of the founding fathers of rocketry and astronautics. Long before the Wright brothers' first plane flew 120 feet, he was thinking space travel. And when it was still science fiction to most people, he was developing the theory, and doing the math, for multistage rockets.
On this day in 1930 - September 17th - Edgar Dean "Ed" Mitchell was born.
Mitchell was the lunar module pilot for the Apollo 14 mission and the sixth man to walk on the Moon.
On this day in 1764 - September 17th - English astronomer John Goodricke was born.
Goodricke is best known for his study of the variable star Algol. He was the first to propose that the variability was due to Algol being two stars orbiting each other. His work earned him an award from the Royal Society. Goodricke College at the University of York is named for him.
On this day in 1977 - September 18th - Voyager 1 took the first ever photo of both the Earth and the Moon together in space.The crescent Moon is very faint in the upper left of the photo.
On this day in 2006 - September 18th - Anousheh Ansari was the first self-funded woman to travel to the space station.
Ansari is an Iranian American engineer and co-founder and chairwoman of Prodea Systems.
On this day in 1970 - September 20th - Luna 16 landed on the Moon.
The Soviet craft was the first robotic probe to land on the Moon and return a sample of lunar soil to Earth.
On this day in 1969 - September 21st - during a comet-hunting expedition, Klim Churyumov and Svetlana Gerasimenko discovered the object subsequently named Comet 67P/Churyumov-Gerasimenko.This was the comet that would later be orbited and studied by ESA's Rosetta Mission.
On this day in 1886 - September 21st - H.G. Wells was born.
This English writer is considered to be one of the fathers of science fiction.
On this day in 2003 - September 21st - NASA's Galileo mission was ended by having the spacecraft plunge into Jupiter.
Galileo was the first spacecraft to orbit Jupiter, the first to achieve an asteroid flyby (951 Gaspra), and it discovered the first asteroid moon - Dactyl, around asteroid 243 Ida.
On this day in 1999 - September 22nd - NASA's Pioneer 10 reached the distance of 50 AU from the Sun.
The spacecraft was the first one to cross the Asteroid Belt, and it carried out the first mission to Jupiter. It was also the first to reach escape velocity from the Solar System. At 50 AU from the Sun, it was 50 times farther away from the Sun than Earth is, about 7.5 billion km (4.7 billion miles). It's now over 124 AU away.
On this day in 2006 - September 22nd - the solar mission Hinode was launched.
Hinode [Sunrise] is a Japanese solar mission with USA and UK collaboration. It was planned as a three-year mission to explore the magnetic fields of the Sun, but is still collecting data.
On this day in 2014 - September 22nd - NASA's MAVEN mission went into orbit around Mars.
MAVEN (Mars Atmosphere and Volatile EvolutioN) is studying the Martian atmosphere.
On this day in 1556 - September 22nd - Danish noblewoman and horticuturalist Sophia Brahe was born.She was also knowledgable in astronomy, chemistry and medicine. The younger sister of Tycho Brahe, she often assisted him with his astronomical observations.
On this day in 1783 - September 23rd - Caroline Herschel discovered NGC 253 The Sculptor Galaxy.Also known as the Silver Coin or Silver Dollar Galaxy, NGC 253 is a starburst spiral galaxy in the constellation Sculptor.
On this day in 1846 - September 23rd - Johann Galle discovered Neptune.Galle had received calculations from Urbain LeVerrier which showed where there might be a new planet, and Galle found the planet that very night. Eventually, it was named Neptune, after the Roman sea god.
On this day in 1930 - September 24th - John Young was born.As a NASA astronaut, Young had a long career which included being the ninth person to walk on the Moon when he was the Commander of the Apollo 16 mission in 1972.
On this day in 2014 - September 24th - the Indian Space Research Organisation (ISRO)'s Mars Orbiter Mission (MOM) entered Mars orbit.
MOM was India's first interplanetary mission and is still studying Mars.
On this day in 1634 - September 25th - Danish astronomer Ole Christensen Rømer was born.He is best known for making the first quantitative measurements of the speed of light by precisely measuring the length of time between eclipses of Jupiter by one of its moons.
On this day in 1814 - September 27th - American astronomer Daniel Kirkwood was born.
Kirkwood is best known for his study of asteroid orbits. When arranging the then-growing number of discovered asteroids by their distance from the Sun, he noted several gaps, now named Kirkwood gaps. He associated these gaps with orbital resonances with the orbit of Jupiter.
On this day in 2007 - September 27th - NASA's Dawn spacecraft was launched.Dawn orbited and studied the asteroid Vesta, and then went on tosatudy dwarf planet Ceres. The mission is finished, but it's still in orbit around Ceres.
On this day in 1605 - September 28th - French astronomer and mathematician Ismaël Bullialdus was born.
Often regarded as ‘the most noted astronomer of his generation’ he wrote several books, the most famous being Astronomia Philolaica, in which he supported Johannes Kepler’s elliptical planetary orbits. Bullialdus was also a defender of the views and ideas of Copernicus and Galileo.
On this day in 1765 - September 29th - German astronomer Karl Ludwig Harding was born.
He is best remembered for the discovery of the third asteroid - Juno - made on 1 Sep 1804 while working at the private observatory of his countryman and fellow astronomer Johann Hieronymus Schröter.
On this day in 1880 - September 30th - Henry Draper took the first photograph of a nebula, the Orion Nebula.Draper was an American physician, professor of medicine, keen astronomer and pioneer of astrophotography. Stars with HD numbers are listed in the Henry Draper Catalog compiled by Harvard College Observatory and funded by Draper's widow, Anna Draper.
On this day in 2016 - September 30th - ESA's Rosetta mission ended with a controlled descent to the surface of Comet Churyumov-Gerasimenko.
On this day in 1897 - October 1st - the 40-inch refracting telescope was dedicated at Yerkes Observatory in Williams Bay, Wisconsin.
From 1897-1909 it was the world's largest telescope. It's still the world's largest refractor.
On this day in 1958 - October 1st - NASA was founded.
On this day in 1920 - October 2nd - Italian mathematician and engineer Giuseppe 'Bepi' Colombo was born.
Colombo, known as "Grandfather of the fly-by", suggested to NASA in 1970 that its Mariner 10 mission could achieve a second fly-by of Mercury by making use of the planet's gravity. A careful analysis showed this could indeed be done and was incorporated into the mission. ESA (European Space Agency) has commemorated him by naming its Mercury mission BepiColombo.
On this day in 1935 - October 3rd - Apollo 16 astronaut "Charlie" Duke was born.
Duke was the Lunar Module Pilot of Apollo 16 and the tenth and youngest person to walk upon the surface of the Moon.
On this day in 1957 - October 4th - the Soviet Union launched Sputnik 1.Sputnik was the world's first successful artificial satellite.
On this day in 1959 - October 4th - the Soviet Union launched Luna 3.
The spacecraft captured humanity's first-ever view of the far side of the Moon.
On this day in 1882 - October 5th - Robert Goddard was born.
Goddard was an American engineer, professor, physicist, and inventor who is credited with creating and building the world's first liquid-fuelled rocket. Although he received little public support in his lifetime, he's now considered one of the founding fathers of modern rocketry.
On this day in 1923 - October 5th - Edwin Hubble discovered a Cepheid variable in M31 (the Andromeda Galaxy).Cepheid variable stars, based on the work of Henrietta Leavitt, can be used as distance indicators. Hubble was able to show that M31 was too far away to be an object in our own Galaxy.
On this day in 1962 - October 5th - the European Southern Observatory (ESO) was founded.
It's a highly productive astronomical observatory, providing state-of-the-art research facilities to astronomers and astrophysicists of many countries.
On this day in 1732 - October 6th - English astronomer Nevil Maskelyne was born in London.
He was the fifth Astronomer Royal of England, holding the post for 46 years. Maskelyne founded the Nautical Almanac and Astronomical Ephemeris, the first nautical almanac to contain data dedicated to the convenient determination of longitude at sea.
On this day in 1885 - October 7th - Niels Bohr was born.
Bohr was the Danish physicist who made foundational contributions to understanding atomic structure and quantum theory, for which he received the Nobel Prize in Physics in 1922.
On this day in 1873 - October 8th - Danish chemist and astronomer Ejnar Hertzsprung was born in Copenhagen.
The Hertzsprung-Russell diagram is a classification system for explaining stellar types and stellar evolution. Hertzsprung and American astronomer Henry Norris Russell independently made the discoveries that created the diagram.
On this day in 1873 - October 9th - German physicist and astronomer Karl Schwarzschild. was born.
Although his best known research relates to general relativity, Schwarzschild worked on a wide range of subjects including celestial mechanics quantum mechanics, spectroscopy and instrumental astronomy.
On this day in 1873 - October 9th - Kepler's Supernova was first observed.It occurred about 20,000 light years away in the constellation Ophiuchus. It was so bright that at its peak it was visible during the day for over three weeks.
On this day in 1846 - October 10th - English businessman and astronomer William Lassell discovered Triton, Neptune's largest moon.Lassell discovered the moon just 17 days after German astronomer Johann Galle discovered Neptune, using Urbain LeVerrier's calculations.
On this day in 1980 - October 10th - the Very Large Array (VLA) was dedicated.
Now known as the Karl G. Janksy Array, it's an important radio telescope facility in New Mexico. Jansky was a pioneer of radio astronomy.
On this day in 1758 - October 11th - German physician and astronomer Heinrich Olbers was born.
Olbers is best remembered for his discovery of the asteroids Pallas and Vesta.
On this day in 1964 - October 12th - the Soviet craft Voskhod 1 was launched.
As the first spacecraft to carry three cosmonauts, it was another step forward in manned space flight.
On this day in 1884 - October 13th - Greenwich in the United Kingdom was adopted as the prime meridian of the world.There had been many prime meridians in use by countries around the world. But at the International Meridian Conference held in Washington DC, 25 maritime countries voted to adopt the Greenwich meridian as the longitude line of zero degrees.
On this day in 1993 - October 13th - the British Interplanetary Society was founded in Liverpool, UK by Phillip Cleator.
The society is the oldest space advocacy organisation in the world.
On this day in 1994 - October 13th - NASA's Magellan mission ended with the spacecraft plunging into Venus.
Magellan - also referred to as the Venus Radar Mapper - was the first interplanetary mission to be launched from the Space Shuttle. It mapped the surface of Venus and measured the planetary gravitational field.
On this day in 1788 - October 14th - Irish geophysicist, explorer and astronomer Edward Sabine was born in Dublin.
He's best remembered by astronomers for his research into changes in the Earth’s magnetic field, which he eventually recognised as being associated with solar activity. Using pendulum experiments, Sabine also made the most accurate determination of the exact shape of the Earth up to that time.
On this day in 1829 - October 15th - American astronomer Asaph Hall was born.Hall is best known for his discovery of Phobos and Deimos, the moons of Mars.
On this day in 1987 - October 15th - the NASA/ESA Cassini-Huygens mission was launched to study the Saturnian system.The spacecraft arrived at Saturn in January 2005 and studied the system for nearly twenty years.
On this day in 2003 - October 15th - China launched Shenzhou 5.
Shenzhou 5 was the China's first manned spaceflight, with Yang Liwei as the first Chinese astronaut in space.
On this day in 1785 - October 15th - English astronomer James South was born in London.
South was an active observer and best remembered for his observation of double stars. He and John Herschel compiled a catalog of double stars originally observed by William Herschel, and South went on to observe 458 further double stars. He was awarded both the Gold Medal of the Royal Astronomical Society and the prestigious Copley Medal of the Royal Society.
On this day in 1956 - October 17th - former NASA astronaut Mae Jemison was born.Jemison - engineer, doctor, university professor and businesswoman - became the first black woman to travel into space when she served as a mission specialist aboard the Space Shuttle Endeavour.
On this day in 2002 - October 17th - the European Space Agency (ESA) launched the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL).
For six years it was the most sensitive gamma ray observatory ever, and it continues its operations in detecting some of the most energetic radiation coming from space.
On this day in 1967 - October 18th - Venera 4 made the first direct studies of Venus's atmosphere.
The Soviet probe was the first probe to perform a successful in-place analysis of the environment of another planet.
On this day in 1910 - October 19th - Indian-American astrophysicist and Nobel laureate Subrahmanyan Chandrasekhar was born.He's known for his work in stellar evolution including black holes. The Chandrasekhar Limitt is the dividing line between the mass of a star that has spent its nuclear fuel and will collapse into a white dwarf and one massive enough to go out with a bang - a supernova. It's about 1.4 times the Sun's mass.
On this day in 2016 - October 19th - the European Space Agency's ExoMars mission arrived at Mars.
There were two parts to the mission. The Trace Gas Orbiter (TGO) was successfully inserted into orbit and is working as expected. However due to a systems malfunction, the experimental lander Schiaparelli crash landed on Mars.
On this day in 2008 - October 21st - India's space agency, ISRO, launched the Chandrayaan-1 lunar probe.
It was India's first satellite to leave Earth orbit, and the mission also included the first Indian deep space radio communications antenna.
On this day in 1923 - October 21st - the Deutsches Museum in Munich, Germany presented the world's first public planetarium show.
On this day in 1905 - October 22nd - American physicist and radio engineer Karl Jansky was born.
In August 1931 Jansky first discovered radio waves emanating from the Milky Way. He's considered one of the founding figures of radio astronomy.
On this day in 1975 - October 22nd - the Soviet Union's Venera 9 went into orbit around Venus.
The mission included an orbiter - the first to orbit another planet - and a lander, which was the first to return images from another planet.
On this day in 1969 - October 23rd - the discoverers of comet 67P/Churyumov-Gerasimenko announced their discovery to the Central International Bureau of Astronomical Telegrams.ESA's Rosetta spacecraft and the lander Philae lie on the comet - they spent two years studying it.
On this day in 1946 - October 24th - the first photograph of Earth was taken from space.
The photo was taken from a rocket 105 km above the ground; it had been launched from the White Sands Missile Range in New Mexico, USA.
On this day in 1851 - October 24th - English astronomer William Lassell discovered two moons of Uranus, Umbriel and Ariel.
On this day in 1998 - October 24th - NASA's Deep Space 1 spacecraft was launched.
It would go on to test advanced technologies and make a flyby of asteroid 9969 Braille and of comet 19P/Borrelly.
On this day in 2001 - October 24th - NASA's Mars Odyssey was inserted into Martian orbit. It's the longest-surviving continually active spacecraft orbiting a planet other than Earth.
From orbit, it's looking for evidence of past or present water and ice, as well as studying the planet's geology and radiation environment. It also acts as a relay for the Curiosity rover.
On this day in 2007 - October 24th - China launched Chang'e 1.
The unmanned lunar-orbiting spacecraft was part of the first phase of the Chinese Lunar Exploration Program - it was named after the Chinese Moon goddess.
On this day in 1887 - October 25th - American astronomer Henry Norris Russell was born.
Russell was one of the major figures of early 20th century astronomy. He's best known today for his part in creating what's now called the Hertzsprung-Russell diagram which demonstrates stellar evolution. (Danish astronomer Ejnar Hertzsprung independently made the same discovery.)
On this day in 2006 - October 25th - NASA launched STEREO.
STEREO was a solar observation mission using two identical spacecraft in two slightly different orbits. That permitted stereoscopic imaging of the Sun. The mission lasted longer than the two years for which it was planned, but in 2014 STEREO-B malfunctioned and couldn't be recovered. STEREO-A is still operational.
On this day in 1671 - October 25th - Jean Dominique Cassini discovered Iapetus, moon of Saturn.
On this day in 1789 - October 25th - the German astronomer Samuel Heinrich Schwabe was born.
He is best known for his work on sunspots and the discovery of the 11-year sunspot cycle.
On this day in 1902 - October 26th - American astronomer Henrietta Hill Swope was born in St. Louis, Missouri.
She is best known for his work on variable stars, especially the study of Cepheid variables which can be used to measure the distances to other galaxies.
On this day in 1961 - October 27th - SA-1, the first Saturn space launch vehicle, was launched from Cape Canaveral, Florida.
This was the first mission of the Apollo program - Saturn V space launch vehicles eventually took astronauts to the Moon.
On this day in 1971 - October 28th - SA-1, the United Kingdom became the sixth nation to launch a satellite.
The Prospero satellite, the only satellite launched by a British rocket, carried a series of experiments to investigate the effects of the space environment.
On this day in 1971 - October 30th - SA-1, the European Space Agency (ESA) launched its first successful Ariane 5 rocket.
The Ariane 5, Europe's most powerful launch vehicle, has been used to launch the XMM-Newton X-ray observatory, numerous telecom satellites, all of the International Space Station ATV resupply ships, the Herschel Space Observatory, and the Rosetta mission.
On this day in 2005 - October 31st - the Hubble Space Telescope discovery of two new moons of Pluto was announced.
The moons were later named Nix and Hydra.
On this day in 1930 - October 31st - Apollo astronaut Michael Collins was born.Collins, a former Air Force test pilot, was the Command Pilot for the Apollo 11 mission.
On this day in 1919 - November 1st - Anglo-Austrian mathematician and cosmologist Hermann Bondi was born.
Bondi was a distinguished academic and Fellow of the Royal Society. Among many positions outside academia, from 1967-1971, he served as Director-General of the European Space Research Organisation (ESRO) which later became the European Space Agency, (ESA).
On this day in 1917 - November 2nd - the 100-inch telescope on Mount Wilson saw first light.
Edwin Hubble would make observations with this telescope that showed there was much more to the Universe than just our own Galaxy.
On this day in 1885 - November 2nd - American astronomer Harlow Shapley was born.
Shapley was the director of the Harvard College Observatory for thirty years, and he was known as an expert in his main area of study, the Milky Way.
On this day in 2000 - November 2nd - Expedition 1 arrived at the International Space Station (ISS).
The ISS has been continuously occupied ever since then. 241 people from around the world have lived and worked on the space station since Nov. 2, 2000.
You do such a fantastic job with your Astronomy site, it's always interesting to get a glimpse of our universe. This year I've had the chance to see what I think are comets during daylight hours (Alberta, Canada) and I believe on Saturday night it may have been Neowise frolicking across the massive prairie sky again, but can't find a source to verify. Are there any websites or apps that you can recommend for comet, asteroid, or satellite tracking? Thanks
Monika, Neowise hasn't been visible to the naked eye since the summer. But if you're seeing frolicking, you may actually be catching glimpses of Taurid meteors. Comets don't appear to move while you watch. Now meteors, in my experience, are so quick they're gone between someone's "Look!" and my eyeball moving. But I have seen Taurid meteors that move slowly.
Can the International Space Station and various satellites be seen from your house? If so, when and where should you look? What are the two bright stars you've seen around sunset time? The website Heavens-Above is a tool for beginners and experienced observers to identify what's in the sky. It includes interactive sky maps. Heavens-Above – websiteCosmic Pursuits is focused on North America
and gives a monthly rundown on what's in the sky this month.
I guess my biggest fear has come true: UFOs and war of the worlds.
What we saw moved very slowly and had a distinct white tail, but not like an airplane. When we saw what we thought was Neowise in the summer, it had the same appearance, but this past weekend when we saw it again, it moved slowly, then the clouds moved over it and it reappeared in a very different location but still slow-moving. It was very unusual.
I've seen a flaming meteor once, it hit the ground in Saskatchewan. I knew I had witnessed something special then too. But this thing was out of this world. I will investigate the links and yes, I've seen the space station twice in my life. It's super fast.
On this day in 1957 - November 3rd - Sputnik 2 carried the dog Laika into space.Laika was the first living creature to orbit the Earth.
On this day in 1871 - November 4th - American astronomer William Hammond Wright was born.Among his accomplishments was the research carried out into the radial velocity of stars in the southern sky. This was mainly done at the Chile station of California's Lick Observatory. He later became the director of Lick Observatory, a post he held from 1935-1942.
On this day in 2013 - November 5th - the Indian Space Research Organisation (ISRO) launched the Mars Orbiter Mission (MOM).
MOM - also called Mangalyaan ("Mars-craft" in Sanskrit) was India's first interplanetary mission. In September 2020 it completed its sixth year in orbit.
On this day in 2018 - November 5th - Voyager 2 entered interstellar space.
It was the second spacecraft to cross the heliopause. This is where the tenuous, hot solar wind meets the cold, dense interstellar medium. Voyager 1 crossed this boundary in 2012.
On this day in 1572 - November 6th - Tycho Brahe recorded his observation of a bright new star (now listed as supernova SN 1572) in the constellation Cassiopeia.The understanding of the time was that the stars were part of a sphere which was perfect and unchangeable, so the new object was assumed to be a local phenomenon. However, Tycho's study showed that it was a distant object.
On this day in 1631 - November 7th - French priest and astronomer Pierre Gassendi observed a transit of Mercury.Johannes Kepler had predicted transits of Mercury and Venus, but when Gassendi witnessed a transit of Mercury, he was the first person to see such a transit. There was a transit of Mercury in November 2019, but the next one doesn't occur until November 13, 2032.
On this day in 1656 - November 8th - English astronomer and master of other sciences Edmond Halley was born.Halley was one of the greatest minds of his era. He is still known today for Halley's Comet, which bears his name after he correctly predicted its return.
On this day in 1934 - November 9th - American astronomer Carl Sagan was born.
Sagan was also noted as a science writer and communicator, and is still remembered for his television series Cosmos. In 2009 Carl Sagan Day was initiated as an annual celebration of astronomy and of Sagan's ideals.
On this day in 1967 - November 9th - a Saturn V launch vehicle took the unmanned Apollo 4 into space.
It was the first test of the Saturn V rocket, which would be used by the U.S. Apollo program to send astronauts to the Moon.
On this day in 2005 - November 9th - the European Space Agency (ESA) Venus Express spacecraft was launched.
The main objective was the long term observation of the Venusian atmosphere - which the mission did for nearly nine years.
On this day in 1861 - November 10th - Scottish astronomer Robert T. A. Innes was born.
Innes is best known for his discovery of Proxima Centauri, the closest star to Earth after the Sun.
On this day in 1875 - November 11th - American astronomer Vesto Slipher was born.
Slipher was director of the Lowell Observatory in Arizona, and the first to discover the redshift of galaxies when he obtained their spectra and measured their radial velocities. This laid the foundation for the work that Edwin Hubble's work on the expansion of the Universe.
On this day in 1910 - November 11th - American astronomer Carl Alvar Wirtanen was born.Wirkenen worked at Lick Observatory in California. He's best known for his discovery of periodic comet 46P/Wirtanen and eight asteroids.
On this day in 2014 - November 12th - the Philae probe became the first spacecraft to land on a comet.Philae was the lander carried by the Rosetta mission of the European Space Agency (ESA) to comet 67P/Churyumov-Gerasimenko.
On this day in 1891 - November 12th - American astronomer Seth Barnes Nicholson was born.
Nicholson worked at Mount Wilson Observatory in California for over 40 yrs, mainly concerned with solar activity. But he also computed the orbit of several comets, discovered a Trojan asteroid, and is probably best remembered for his discovery of four satellites of Jupiter.
On this day in 1680 - November 14th - German astronomer Gottfried Kirch discovered the comet C/1680 V1.
It was the first comet to be discovered using a telescope, and became one of the brightest comets of the 17th century.
On this day in 1971 - November 14th - NASA's Mariner 9 was inserted into Martian orbit.
Mariner 9 was the first spacecraft to orbit Mars.
On this day in 1738 - November 15th - William Herschel was born in Hannover, now part of Germany.Herschel, a naturalized Englishman, was the first person in history to discover a new planet (Uranus). Working in partnership with his sister Caroline, he helped to lay the foundations of modern astronomy.
On this day in 1974 - November 15th - Spain launched its first satellite, Intasat, on a Delta rocket from Vandenburg Air Force Base in the United States.
Intasat was a small spacecraft carrying a beacon experiment to study the ionosphere. It was in operation for two years.
On this day in 1970 - November 17th - the Soviet Mission Luna 17 landed on the Moon.
Luna 17 contained the Lunokhod 1 rover, the first wheeled vehicle on Moon.
On this day in 1995 - November 17th - the European Space Agency (ESO) launched the Infrared Space Observatory (ISO).
It was the first orbiting infrared observatory that allowed astronomers to make sensitive observations at infrared wavelengths.
On this day in 1923 - November 17th - NASA astronaut Alan Shepard was born.
Shepard was the first American in space, though not the first to orbit. He later commanded the Apollo 14 mission to the Moon.
On this day in 1989 - November 18th - NASA's Cosmic Background Explorer (COBE) was launched.
COBE was a cosmology satellite that investigated the cosmic microwave background radiation (CMB). It provided key pieces of evidence that supported the Big Bang theory of the Universe.
On this day in 2013 - November 18th - NASA's MAVEN spacecraft was launched.
The Mars Atmosphere and Volatile Evolution Mission (MAVEN) is a space probe designed to study the Martian atmosphere from Mars orbit.
On this day in 1956 - November 19th - NASA astronaut Eileen Collins was born.
Collins, who had been a military test pilot, was the first woman to pilot a space shuttle and the first woman commander of a space shuttle.
On this day in 1918 - November 19th - Dutch astronomer and mathematician Hendrik C. van de Hulst was born.
Hulst predicted the existence of the 21 cm hyperfine line of neutral interstellar hydrogen. When it was discovered, he worked with Jan Oort and others to use radio astronomy to map out the neutral hydrogen in the Milky Way, which first revealed our galaxy's spiral structure.
On this day in 1969 - November 19th - Apollo 12 astronauts landed on the Moon in the southeastern part of the Ocean of Storms.
Mission commander Charles "Pete" Conrad and Lunar Module Pilot Alan L. Bean carried out lunar surface tasks, Command Module Pilot Richard F. Gordon remained in lunar orbit.
On this day in 1932 - November 19th - American astronomer Eleanor Francis “Glo” Helin was born.
Helin was active in planetary science and astronomy at Cal Tech and NASA's Jet Propulsion Laboratory for over three decades. Among her many achievements were the discovery of hundreds of asteroids and several comets.
On this day in 2005 - November 19th - the Hayabusa spacecraft of Japan Aerospace Exploration Agency (JAXA) became the first ever to lift off from an asteroid.
It had collected a sample of material from near-Earth asteroid 25143 Itokawa, which it then returned to Earth.
On this day in 1889 - November 20th - American astronomer Edwin Hubble was born.
He showed that the Universe was much bigger than our own Galaxy, and his observations provided evidence for an expanding universe. The Hubble Space Telescope is named for him.
On this day in 1998 - November 20th - the Zarya module was launched from Baikonur Cosmodrome, Kazakhstan.
Zarya was the first module of the International Space Station. A much expanded space station is still operating with crews made up of astronauts from many nations.
On this day in 2004 - November 20th - NASA's Swift Gamma-Ray Burst Mission was launched. (It's now called the Neil Gehrels Swift Observatory.)
The mission, with international participation, was designed to help solve the mystery of gamma-ray bursts.
On this day in 1977 - November 23rd - Meteosat-1 was launched by EUMETSAT (a European intergovernmental agency).
Meteosat-1 was the first of the first generation of Meteosat satellites, which have provided continuous and reliable meteorological observations from space to a large user community.
On this day in 1816 - November 25th - American lawyer, astronomer and pioneering astrophotographer Lewis Morris Rutherfurd was born.
After practicing law for a number of years, Rutherfurd gave it up for astronomy. He was a pioneer of astrophotography, inventing the first telescope designed specifically for astrophotography. With the telescope he made high quality images of the Sun, Moon and planets as well as star clusters and stars down to around fifth magnitude. Rutherfurd was an associate of the Royal Astronomical Society, and one of the original members of the National Academy of Sciences.
On this day in 2011 - November 26th - the Mars Science Laboratory rover Curiosity was launched.
Curiosity is still exploring Mars.
On this day in 1965 - November 26th - France became the third nation to launch its own satellite.
Astérix was launched from a site in French Algeria.
On this day in 1864 - November 26th - French astronomer Auguste Honoré Charlois was born.
He is best remembered for discovering 99 asteroids over a 17-year period while working at the Nice Observatory.
On this day in 1701 - November 27th - Swedish astronomer, mathematician and physicist Anders Celsius was born in Uppsala.
Best known for his 'degrees Celsius' temperature scale, he was also professor of astronomy at Uppsala University, and he created the Celsius Observatory in Uppsala.
On this day in 1885 - November 27th - the first known photograph of a meteor was taken.Austro-Hungarian astronomer Ladislaus Weinek caught a 7mm-long trail at his Prague observing station during the Andromedid meteor shower. (Since the 19th century the Andromedids have faded so much that they're no longer generally visible to the naked eye.)
On this day in 1971 - November 27th - the Soviet Mars 2 probe became the first man-made object to reach the surface of Mars.
However it wasn't the first successful mission, because the landing system failed and the lander was lost.
On this day in 1964 - November 28th - NASA's Mariner 4 was launched.
The spacecraft made the first successful flyby of the planet Mars, returning the first pictures of the Martian surface. They were the first images of another planet ever returned from deep space.
On this day in 1967 - November 28th - at the Mullard Radio Astronomy Observatory, Cambridge, England, the first pulsar was observed by Jocelyn Bell and Antony Hewish.A pulsar is a rapidly rotating neutron star, but at the time no one knew this. A neutron star was still a theoretical construct whose existence wasn't generally accepted by astronomers.
On this day in 1967 - November 29th - Australia became the 4th nation to launch a satellite from its own territory.
The satellite (Wresat) was a joint venture of the Weapons Research Establishment and the University of Adelaide's Physics Department. It collected and sent back data about the composition of the upper atmosphere for 73 orbits.
On this day in 1609 - November 30th - Galileo Galilei made his first detailed observations of the Moon using a telescope.
Using a telescope with 20x magnification, he examined and drew the Moon from 30 November to 18 December.
On this day in 2013 - December 1st - China's Chang'e-3 spacecraft was launched to Moon.
It was made up of a lander and the rover Yutu which would be deployed for a time on the lunar surface.
On this day in 1993 - December 2nd - the first Hubble Space Telescope servicing mission was launched.
The crew of the Space Shuttle Endeavour went to the telescope with a new main camera and a corrective optic package to restore the telescope's blurred vision.
On this day in 1995 - December 2nd - the NASA/ESA Solar and Heliospheric Observatory (SOHO)was launched.
It was originally planned as a two-year mission, but it's still providing essential data about the Sun and space weather.
On this day in 2014 - December 3rd - the Japanese spacecraft Hayabusa 2 was launched.
Hayabusa 2 is an asteroid sample-return mission which rendezvoused with near-Earth asteroid 162173 Ryugu in June 2018.
On this day in 2015 - December 3rd - ESA's LISA Pathfinder mission was launched.
LISA (Laser Interferometer Space Antenna) Pathfinder tested technology for a future spaceborne observatory for gravitational waves.
On this day in 1639 - December 4th - Jeremiah Horrocks and William Crabtree in England became the first people ever to observe a transit of Venus.Horrocks predicted the transit based on his own corrections to Kepler's Rudolphine Tables.
On this day in 1997 - December 4th - NASA's Mars Pathfinder was launched.
Mars Pathfinder was a robotic spacecraft that landed a base station (named the Carl Sagan Memorial Station) and Sojourner, the first roving probe on Mars.
On this day in 1968 - December 6th - ESRO (a precursor to the European Space Agency) had its Highly Eccentric Orbit Satellite (HEOS-1) launched from Cape Kennedy.
It was the first European satellite to venture beyond near-Earth space. It studied magnetic fields, radiation and the solar wind, which required an orbit stretching two-thirds of the way to the Moon.
On this day in 1998 - December 6th - the Unity and Zarya modules were connected to form the core of the International Space Station (ISS).
The ISS was first occupied on November 2, 2000 and has been in continuous occupation ever since.
On this day in 1676 - December 7th - the first news was published of Danish astronomer Ole Rømer's measurement of the speed of light.Rømer's work was based on observations of the eclipses of the moons of Jupiter. At that time not everyone was convinced that light even had a finite speed.
On this day in 1905 - December 7th - Gerard Kuiper was born.
Among the Dutch-American astronomer's discoveries is Neptune's moon Miranda. Kuiper is considered by many to be the father of modern planetary science.
On this day in 1995 - December 7th - NASA's Galileo spacecraft entered Jupiter's atmosphere and began its prime mission.
Galileo was the first spacecraft to orbit Jupiter, though others had done fly-bys of the giant planet.
On this day in 2018 - December 7th - China launched the Chang'e 4 lunar spacecraft mission.
The mission included a robotic lander and the rover Yutu-2.
On this day in 1842 - December 8th - French astronomer Alphonse Louis Nicolas Borrelly was born.
At the Marseille Observatory, Borrelly discovered 18 asteroids and discovered or co-discovered at least six comets, including the periodic comet 19P/Borrelly. That comet was photographed by NASA's Deep Space 1 in September 2001. It next rounds the Sun on February 1, 2022.
On this day in 2010 - December 8th - SpaceX Dragon 1 was launched, the first private spacecraft recovered from orbit.
On this day in 1999 - December 10th - the European Space Agency (ESA) launched the Newton X-Ray Multi-Mirror Telescope (XMM-Newton).
XMM-Newton, named after Sir Isaac Newton, investigates interstellar X-ray sources and performed the first simultaneous imaging of objects in both X-ray and optical (visible and ultraviolet) wavelengths. Although planned to be operational for 10 years, the telescope is still in operation.
On this day in 1863 - December 11th - American astronomer Annie Jump Cannon was born.Cannon classified nearly a quarter of a million star spectra for the Henry Draper Catalogue and oversaw its publication after the death of Edward Pickering, the Harvard College Observatory director.
On this day in 1972 - December 11th - NASA's last manned lunar mission, Apollo 17, landed on the Moon.
On this day in 1805 - December 13th - Scottish-German astronomer Johann von Lamont (John Lamont) was born.
He calculated the orbits of moons of Uranus and Saturn, but his most important work was on the Earth's magnetism.
On this day in 1904 - December 13th - Irish theoretical physicist Sir William Hunter McCrea was born.
McCrea made contributions to mathematics, physics and almost every area of astronomy, but is best known for his seminal work in modern relativistic cosmology. He was elected a Fellow of the Royal Society and the Royal Society of Edinburgh, the Royal Astronomical Society, the Royal Irish Academy, and was awarded many other honors.
On this day in 1546 - December 14th - Danish astronomer Tycho Brahe was born.Tycho was the greatest ever observer in the days before the telescope. His extensive collection of accurate observations made it possible for Kepler to work out the orbits of the planets.
On this day in 1962 - December 14th - NASA's Mariner 2 made the first successful planetary flyby when it had its encounter with Venus.
The last transmission from the spacecraft was received on January 3, 1963, but it remains in heliocentric orbit.
On this day in 2013 - December 14th - the China National Space Administration (CNSA) Chang'e-3 spacecraft landed on the Moon.
The craft was composed of a lander and the Yutu rover. It was the first soft landing on the Moon since the Soviet Union's Luna 24 in 1976.
On this day in 1970 - December 15th - Venera 7 was the first spacecraft to make a soft landing on another planet and transmit data.
The Soviet probe survived on Venus for 53 minutes, 20 of them on the surface.
On this day in 1826 - December 16th - Italian astronomer Giovanni Battisti Donati was born in Pisa.
He's best remembered for the discovery of several comets, including the one that is named for him. Donati's comet was a spectacular sight in the sky in late 1858.
On this day in 1857 - December 16th - American astronomer Edward Emerson Barnard was born in Nashville, Tennessee.
He was one of best visual observers of his day as well as a pioneer of celestial photography. Barnard's Star was named for him. It's a red dwarf star for which Barnard measured its proper motion relative to the Sun.
I saw a video of this on Youtube. But It showed there they landed on a sea. Isn't Venus dry?
Yes, Krztypie, Venus is dry. The surface temperature is 872 F (467 C), hot enough to melt lead. (But there aren't any lead puddles there either!) And certainly no seas.
ESA's Huygens probe to Titan was designed to float when it landed, if that were necessary. It wasn't, though Titan does have some hydrocarbon seas and lakes.
I wonder what the video was that you saw.
On this day in 1917 - December 16th - British author, futurist, inventor and explorer Arthur C. Clarke was born in. Clarke wrote more than 100 books, and he inspired scientists and space explorers. In honor of his work, the International Astronomical Union named the distance of 36000 km above Earth the Clarke Orbit, and in 2018 they named a mountain on Pluto's moon Charon for him.
On this day in 1999 - December 18th - NASA launched the Terra satellite.
Terra was the flagship of the Earth Observation System, a multinational research program to study changes in the Earth and how they could affect life on our planet.
On this day in 2013 - December 19th - the European Space Agency (ESA) launched its Gaia spacecraft.
Gaia is a space observatory which is measuring the positions and distances of stars with unprecedented accuracy. The mission aims to construct the largest and most precise 3D space catalog ever made.
On this day in 1904 - December 20th - The Mount Wilson Solar Observatory was founded.
About fifteen years later, "solar" was dropped from the name as the 100-inch Hooker telescope came into use. Observing with it, Edwin Hubble found evidence that the Milky Way was just one galaxy in an expanding Universe.
On this day in 1986 - December 21st - NASA launched Apollo 8 with its crew of Frank Borman, Jim Lovell and William Anders.
The Apollo 8 Moon mission was the first manned mission to leave Earth orbit and go into orbit around another celestial object.
On this day in 1988 - December 21st - Cosmonauts Vladimir Titov and Musa Manarov returned to Earth after spending one year aboard Mir space station.
On this day in 2020 - December 21st - the winter solstice occurred at 10:02 UCT.
This is the shortest day of the year in the northern hemisphere and the North Pole is at its maximum tilt away from the Sun. The southern hemisphere has its longest day and the South Pole is at its maximum tilt towards the Sun.
On this day in 1672 - December 23rd - the winter solstice occurred at 10:02 UCT.Jean-Dominique Cassini discovered Saturn's moon Rhea.
On this day in 1968 - December 24th - Apollo 8 entered lunar orbit.The crew were the first humans to view Earth as a whole planet, the first to orbit another world, and the first to see the far side of the Moon. They made a live Christmas Eve broadcast to the Earth as they circled the Moon.
On this day in 1758 - December 25th - German amateur astronomer Johann Georg Palitzsch became the first to view Halley's Comet on its return to the inner solar system.The comet's return had been predicted by the English scientist and astronomer Edmond Halley, after whom it was subsequently named.
On this day in 2003 - December 25th - the European Mars Express and British Beagle 2 arrived at Mars.Beagle 2 was damaged on landing and never responded, but the orbiter Mars Express is still returning data.
On this day in 2004 - December 25th - the Huygens probe separated from the Cassini spacecraft.
Huygens went on to land on Saturn's moon Titan, and Cassini studied the Saturnian system until 2017.
On this day in 1780 - December 26th - Mary Somerville was born in Jedburgh, Scotland.Somerville was one of the leading lights of 19th century science. She was an able mathematician and she published books on developments in astronomy, physics and geography. Somerville was honored by several learned societies, even when she would not have been allowed to attend their meetings.
On this day in 1571 - December 27th - Johannes Kepler was born near Stuttgart in Germany.Using the data of Tycho Brahe, Kepler formulated the three laws planetary motion which were the foundation for our modern view of the Solar System. They could describe planetary orbits simply, but required the Sun - not the Earth - to be at the center of the Solar System.
On this day in 1882 - December 28th - English astrophysicist Arthur Eddington was born.Eddington was one of the most eminent scientists of his day, and was made famous by testing Einstein's theory of general relativity during a total solar eclipse.
On this day in 2005 - December 28th - GIOVE-A, the first Galileo satnav system satellite, was launched.
Galileo is Europe's global navigation satellite system, developed under a partnership between the European Space Agency (ESA) and the European Commission (EC).
On this day in 1789 - December 28th - Scottish astronomer Thomas Henderson was born.
He was based at the Royal Observatory, Cape of Good Hope, South Africa during the early-1830s and after his return to his native Scotland, he became Astronomer Royal for Scotland from 1834 to 1844.
On this day in 1888 - December 29th - pioneering Welsh astrophotographer Isaac Roberts took the first detailed picture of another galaxy, the Great Nebula in Andromeda.
Roberts went on to systematically photograph the brightest nebulae and star clusters visible from England, and received international recognition for his work.
On this day in 1928 - December 30th - the Belgian astronomer Henri Debehogne was born.
Debehogne worked at the Royal Observatory of Belgium in Uccle where he specialized in the astrometry of comets and minor planets. The Minor Planet Center of the International Astronomical Union (IAU) credited him with over 700 discoveries of minor planets.
On this day in 1864 - December 31st - Robert Grant Aitken was born.
Aitken was an American astronomer of international repute. He was best known for his systematic study of double stars, and served for ten years as chair of the double star committee of the International Astronomical Union.