BellaOnline Forums Education Astronomy Solar System Discoveries – Quiz *new quiz*

Since prehistoric times people have known the Sun, the Moon and five planets. The rest of the Solar System had to await discovery by people with telescopes. How many of the discoverers can you identify?

Solar System Discoveries – Quiz

Galileo is given credit for the discovery of Jupiter's four biggest satellites. He documented his observations and published them. A German astronomer named Simon Marius claimed that he had discovered them before Galileo. The evidence in his favor is sketchy. In any case, all else being equal, credit is usually given to the person who first makes the findings public.

Click here to find out more about Jupiter's Galilean Moons.

There was a 45-year gap between Galileo's discovery of the moons of Jupiter and Huygens's discovery of a moon orbiting Saturn. This seems surprising considering how really big Titan is. However Saturn is over twice as far away from us as Jupiter is. Huygens had access to better telescopes and one of his many areas of expertise was optics and lenses.

There are five planets you can see without a telescope, so none of them can be kept secret! We can't say that anyone discovered any of them when people have been watching them for thousands of years. Everyone was so used to having just those five, it didn't occur to most people that there could be more of them.

But on March 13, 1781 William Herschel was out in the back yard looking for double stars, which was his special interest. When he found something vaguely fuzzy, he assumed it was a comet and was a bit excited. But in the end it turned out to be a previously unknown planet. He was the first person ever actually to discover a planet.

Both French astronomer & mathematician Urbain LeVerrier, and English astronomer & mathematician John Couch Adams calculated the location of the planet that was influencing Uranus's orbit. It later turned out that their results were very similar. Cambridge University astronomers couldn't find the planet from Adam's calculations. However Johann Galle found it on the day that he received LeVerrier's letter.

The Berlin Observatory had an advantage. In 1825 the Prussian Academy of Sciences initiated the Berlin Academic Star Charts. A new chart that hadn't yet been published enabled Galle to find Neptune.

Who Discovered Neptune?

Bode's Law predicted a planet orbiting at 2.8 AU. (An AU - astronomical unit - is the Earth-Sun distance.) The so-called Bode's Law wasn't discovered by Johann Bode, but rather by Johann Titius. It's not really a law either. It's a formula that gives the distance in AU of planetary orbits. But there was a gap at 2.8 AU - and that's where Piazzi found the first of the asteroids. (The formula breaks down at Neptune, but that hadn't yet been discovered at the time.)

Giuseppe Piazzi discovered Ceres on 01.01.1801 - January 1, 1801. Since then Ceres has been considered (1) a planet, (2) an asteroid, (3) a minor planet, (4) a dwarf planet. Ceres is the name of a Sicilian agricultural goddess. The English word cereal is derived from her name.