China launched a spacecraft that promises to return samples from an asteroid near Mars and yield “groundbreaking discoveries and expand humanity’s knowledge of the cosmos,” the ...

Asteroids are the ancient remnants of our solar system's birth, rocky fragments that never formed into planets. Most of these celestial wanderers inhabit the asteroid belt between Mars and Jupiter, ...

U.S. astronomers hunting for "Planet Nine" have instead stumbled on what appears to be a new dwarf planet in the solar system's outer reaches.