There could be a ninth planet in our solar system that's lying in wait to be discovered - and no, it's not Pluto. Our solar ...

When you buy through links on our articles, Future and its syndication partners may earn a commission. A composite image comparing the relative sizes of our solar system's known dwarf planets, ...

In the cold, distant reaches of the Solar System, far beyond Pluto, astronomers have just identified what could be a new dwarf planet. It's called 2017 OF 201, a rock that appears to be some 700 ...

Astronomers rarely see distant planets directly, instead tracking tiny stellar wobbles and fading light. How do these subtle ...

AMES, Iowa – An international team of astronomers has used nearly three years of high precision data from NASA’s Kepler spacecraft to make the first observations of a planet outside our solar system ...

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 ...

There may be a warp in the Kuiper Belt, possibly caused by “Planet Y” — a Mercury-to-Earth-sized world that orbits the sun way beyond the orbit of Neptune. Is there a mysterious “Planet Y” orbiting ...

A Carnegie-led team of astronomers detected the strongest evidence yet of an atmosphere around a rocky planet beyond our ...

An ultra-hot rocky exoplanet may be wrapped in a dense atmosphere, defying expectations about what small planets can sustain.