The boundary between stars and planets appears increasingly indistinct. Objects such as brown dwarfs, neither fully stars nor ...

Astronomers have discovered a flattened structure of matter around the Milky Way that explains the unusual motion of nearby galaxies.

Mercury, Venus, and Mars sit within the same general neighborhood as Earth, yet each has followed a radically different path.

There is a category of planet that belongs to no star. It was thrown clear of its solar system early in the chaos of ...

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 direction depends on where you are.

Humans did not evolve for space. Ironically, because we insist on going there anyway, scientists now know from studying ...

Astronomers witnessed planets colliding 11,000 light-years away, an event that could shed light on the collision that created Earth's moon.

In our solar system, Jupiter is the undisputed king. If you added more mass to Jupiter, it wouldn’t actually get much bigger ...

Astronomers have caught what may be a rare cosmic catastrophe unfolding 11,000 light-years away. A seemingly ordinary sun-like star suddenly began flickering wildly, puzzling scientists until they ...

Deep canyons in the Andes are the perfect location to catch the most energetic particles in the universe. Carlos ...