For decades, our solar system was thought to have nine planets, with Pluto considered the smallest and farthest. But in 2006, Pluto was officially reclassified as a dwarf planet by the International ...

Earth’s gravity has a lot to do with what people think is up and what is down. Things fall down toward the ground, but that ...

Add Yahoo as a preferred source to see more of our stories on Google. Jupiter is already the biggest planet by far in our solar system, but new research suggests it was somehow once even larger than ...

The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have dubbed ...

Fantasizing about interplanetary exploration is a fun mental exercise, but the harsh realities of life (or lack thereof) in our Solar System is for good reason.

Forbes contributors publish independent expert analyses and insights. An award-winning reporter writing about stargazing and the night sky. Astronomers have found a distant celestial body — ...

An artist's impression shows the "inside out" planetary system around the star LHS 1903. - ESA An exoplanetary system about 116 light-years from Earth could flip the script on how planets form, ...