The Milky Way
Where would we be without it?
The Milky Way - It's more than just a candy bar
There's more to the story...
Look - up in the sky! OH NO! Lookout Milky Way!
Not only is the Milky Way spinning, it is also moving through the universe. Despite how empty space might appear in the movies, it is filled with dust and gas — and other galaxies. The massive collections of stars are constantly crashing into one another, and the Milky Way is not immune.
In about four billion years, the Milky Way will collide with its nearest neighbor, the Andromeda Galaxy. The two are rushing towards each other at about 70 miles per second (112 km per second). When they collide, they will provide a fresh influx of material that will kick of star formation anew.
The Andromeda Galaxy is obviously not the most careful of drivers. It shows signs of having already crashed into another galaxy in the past. Although it is the same age as the Milky Way, it hosts a large ring of dust in its center, and several older stars.
Of course, the imminent collision shouldn't be a problem for inhabitants of Earth. By the time the two galaxies ram headlong, the sun will already have ballooned into a red giant, making our planet uninhabitable.
Milky Way facts
The Milky Way contains over 200 billion stars, and enough dust and gas to make billions more.
The solar system lies about 30,000 light-years from the galactic center, and about 20 light-years above the plane of the galaxy.
More than half the stars found in the Milky Way are older than the 4.5 billion year old sun.
The most common stars in the galaxy are red dwarfs, a cool star about a tenth the mass of the sun. Once thought unsuitable for potential life-bearing planets because such bodies would have to be too close to meet the criteria, red dwarfs are now considered potential suspects.