Gravity is a fundamental force of physics, one which we Earthlings tend to take for granted. You can't really blame us. Having evolved over the course of billions of years in Earth's environment, we ...

Rocky worlds larger than Earth are commonplace in the galaxy, and a few of them may even be habitable. Which poses an interesting question: How difficult would it be for aliens living on these ...

A pair of theoretical physicists are reporting that the same observations inspiring the hunt for a ninth planet might instead be evidence within the solar system of a modified law of gravity ...

Summertime means it’s time to play ball! But what would it be like to play ball on various locations across our Solar System? Planetary scientist Dr. James O’Donoghue has put together a fun animation ...

DENVER — Small but rowdy space rocks pushing and jostling one another may have created the unusual orbits some astronomers cite as the signature of the hypothesized "Planet Nine," a new study suggests ...