Comets and asteroids preserve the building blocks of our solar system and should help explain its origin. But there are unsolved puzzles. For example, how did icy comets obtain particles that formed ...

And the earth was without form and void, and darkness was upon the face of the deep. Sometimes, if the night is dark and clear enough, you can look up and see the Milky Way in its arc across the sky.

"We have been calling Uranus an ice giant, but we don't really know its nature." When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Astronomers say ...