The Milky Way

The Milky Way is our galaxy and it is a vast collection of stars, gas, dust, and dark matter.

Astronomers estimate it contains between 200 to 400 billion stars!

On a clear night, far from city lights, you might see it as a bright white "river of stars" stretching across the sky.

But if you could see it from the outside, you’d notice a spiral galaxy with a central bulge, a flat disk, and arms that spiral outward.

These spiral arms are where most of the gas, dust, and young stars are found and where new stars are born.

The disk of the Milky Way is enormous—it spans about 100,000 light years and is roughly 3,000 light years thick.

Our solar system lies in one of these spiral arms, about 26,000 light-years from the galaxy’s center.

At the center of this galaxy is a supermassive black hole whose immense gravity helps hold the galaxy together.

If the solar system were the size of your fist, the Milky Way’s disk would be larger than the United States!