BellaOnline Forums Education Astronomy The Milky Way - Our Galaxy

The Milky Way is a giant spiral galaxy. Along with our neighboring giant Andromeda Galaxy, it dominates the Local Group of galaxies. But where are we in the Galaxy? Why do astronomers think that 95% of the Galaxy is mysterious dark matter? And what is lurking at the heart of the Milky Way?

Milky Way - Our Galaxy

Milky Way over Deadviel in Namibia.

The trees in Deadvlei, though, have been dead for over 500 years. Located in Namib-Naukluft Park in Namibia (Earth), saplings grew after rainfall caused a local river to overflow, but died after sand dunes shifted to section off the river. High above and far in the distance, the band of our Milky Way Galaxy forms an arch over a large stalk in this well-timed composite image, taken in March 2018. The soil of white clay appears to glow by reflected starlight. Rising on the left, under the Milky Way's arch, is a band of zodiacal light -- sunlight reflected by dust orbiting in the inner Solar System. On the right, just above one of Earth's larger sand dunes, an astute eye can find the Large Magellanic Cloud, a satellite galaxy of our galaxy.

Image Credit & Copyright: Stefan Liebermann
Description: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)

Milky Way over Chilean Volcanoes .

Image Credit & Copyright: Carlos Eduardo Fairbairn
Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)

Great Rift Near the Center of the Milky Way
Rogelio Bernal Andreo used over 100 telescopic image panels in this vertical mosaic span about 50 degrees across the night sky. They follow part of the Great Rift, the dark river of dust and molecular gas that stretches along the plane of our Milky Way Galaxy. Start at top center and you can follow the galactic equator down through brighter stars in constellations Aquila, Serpens Cauda, and Scutum. At the bottom is Sagittarius near the center of the Milky Way. Along the way you'll encounter many obscuring dark nebulae hundreds of light-years distant flanked by bands of Milky Way starlight, and the telltale reddish glow of starforming regions. Notable Messier objects include The Eagle (M16) and Omega (M17) nebulae, the Sagittarius Star Cloud (M24), the beautiful Trifid (M20) and the deep Lagoon (M8).

Description: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)

The Milky Way and the Summer Triangle over the Great Wall of China.
The Summer Triangle is made up the bright stars Vega (bright blue star near the top of the image), Deneb (blue star to the lower left of Vega) and Altair (to the lower right of Deneb.

This part of the Great Wall, a World Culture Heritage Site, was built during the 6th century on the Yan Mountains. At the summit is Wangjinglou Tower from which, on a clear night, the lights of Beijing are visible in the distance.

Image Credit & Copyright: Steed Yu & NightChina.net

They may look like round rocks, but they're alive. Moreover, they are modern versions of one of the oldest known forms of life: stromatolites. Fossils indicate that stromatolites appeared on Earth about 3.7 billion years ago -- even before many of the familiar stars in the modern night sky were formed. In this image taken in Western Australia, only the ancient central arch of our Milky Way Galaxy formed earlier. Even the Magellanic Clouds, satellite galaxies of our Milky Way and visible in the featured image below the Milky Way's arch, didn't exist in their current form when stromatolites first grew on Earth. Stromatolites are accreting biofilms of billions of microorganisms that can slowly move toward light. Using this light to liberate oxygen into the air, ancient stromatolites helped make Earth hospitable to other life forms including, eventually, humans.

Image Credit & Copyright: Jingyi Zhang
Text: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)

The photo is beautiful.