Test your knowledge on our solar system, from the biggest and smallest planets to the behemoth mountain on Mars. When you purchase through links on our site, we may earn an affiliate commission.

Forbes contributors publish independent expert analyses and insights. An award-winning reporter writing about stargazing and the night sky. The solar system suddenly has a new member. A new object ...

When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Our solar system has been around for 4.6 billion years. While that sounds like a long time, it's ...