Astronomers have discovered fresh evidence suggesting the possible existence of an unseen planet in the far reaches of our solar system. The study, published in the Monthly Notices of the Royal ...

A possible cousin of Pluto seems to be circling the far reaches of the solar system. The dwarf planet candidate 2017 OF201 travels in a superwide orbit, with the sun relatively near one end of its ...

A rocky planet nearly 50 light-years away appears to be airless, dark, and covered in volcanic or weathered rock, according ...

Scientists may have discovered a dwarf planet far beyond Neptune — an unearthing that may disprove a longstanding theory about the possibility of a giant ninth planet. The dwarf planet's existence ...

There may be another world lurking between the orbital lines of our solar system. Astronomers in Japan have published their theory of an “Earth-like planet,” dubbed Planet Nine, that’s hiding in plain ...

Mars is the fourth planet from the sun and has a distinct rusty red appearance and two unusual moons. The Red Planet is a ...

CAPE CANAVERAL, Fla. — Astronomers have discovered a rare solar system in the Milky Way that boasts six planets orbiting in perfect rhythm like a cosmic orchestra, untouched by outside forces since ...

On August 24, 2006, our solar system lost a planet. It wasn't by cataclysmic destruction, but rather by the vote of the International Astronomical Union, which declared that Pluto, considered the ...