When we think of a day, we usually imagine 24 hours. But did you know that not all planets have days that last 24 hours? In fact, the length of a day can be very different depending on the planet.

This video explains why planets in our solar system orbit in nearly the same plane, tracing their origins back to a rotating protoplanetary disc of dust and gas that formed around the young Sun. It ...

What would happen if Earth, Mars, and all the planets in our solar system merged into one massive super-planet? In this video ...

People will be able to see a rare sight at the end of this month when all seven other planets in our solar system line up in the night sky. For the last few weeks six of the planets have been visible, ...

A mysterious comet flying through our solar system may be doing more than just passing by-it could help explain how giant planets like Jupiter are born. At a major planetary science conference in ...