Pluto was reclassified as a dwarf planet in 2006. Our solar system may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far into the solar system ...

There have been questions about a mysterious ninth planet in our solar system for nearly a decade. Pluto was unseated as number nine in 2006. Now, a group of international researchers say they may ...

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to [email protected]. Are planets in the solar system that are closer ...

The giant planets weren't always where we find them today. Jupiter, Saturn, Uranus and Neptune formed in a more compact ...

Even the best telescopes can’t see exoplanets. It’s all about watching for jiggly stars, blue shifts, and transits.

Jupiter is already the biggest planet by far in our solar system, but new research suggests it was somehow once even larger than it is now. Twice as large, in fact. To put that into context, those ...

With a lot of talk about space recently, have you ever wondered which are the hottest planets in the solar system? You'd think the closer you are to the sun, the hotter they must be. Now that's mostly ...

Lucas Brefka receives funding from a NASA Exoplanet Research Program grant. Christopher Palma does not work for, consult, own shares in or receive funding from any company or organization that would ...

This article was originally featured on The Conversation. 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 ...