In many cases, the astronomy facts we learned were limited to the Milky Way, a few constellations (looking at you, Orion and Big Dipper!), Earth’s revolution around the sun and the moon’s ...

The International Year of Astronomy coincides with the 400th anniversary of Galileo’s revolutionary telescope this year. So what better way to celebrate history than with a retro look at the cosmos?

In the magazine’s special 500th issue, Astronomy’s editors share their picks for the 500 coolest things about space! Skip to content. Introducing the all-new Astronomy.com Forum!