A four-planet system reveals remarkable insights about how planets form and how they change during their lifetime.

Welcome to the Solar System construction zone. Today you’ll be using our cosmic sandbox to build a brand new planet. What would you need to create a rocky planet like Earth? Where should this planet ...

Mercury has long baffled astronomers because it defies much of what we know about planet formation. A new space mission ...

What was originally thought to be a planet orbiting the Fomalhaut star was probably just the fallout of a wild collision.

Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A cloud of collapsing gas created our Sun, the first thing to form in ...

There are a couple of ways that scientists can date planets, so which planets formed first in our solar system? When you purchase through links on our site, we may earn an affiliate commission. Here’s ...