The small world was found during a search for the hypothetical Planet Nine, and astronomers say the next time it will reach ...

Astronomers find evidence of a possible ninth planet beyond Neptune, reigniting the debate about the formation of the Solar ...

Today, it’s believed that Jupiter and Saturn, the largest planets, were the first to fully form, both within a few million ...

Jupiter, roughly 562 million miles from Earth today, has nearly 100 moons. But Batygin and his collaborator Fred Adams' research focused on two of the smaller ones, Amalthea and Thebe. Both are inside ...

Some astronomers say the strange, clustered orbits of icy rocks beyond Neptune indicate that something big is out there, ...

Scientists directed NASA’s Perseverance rover to take an image of the Martian sky after a solar storm in hopes that an aurora ...