A new study suggests yet another theory for a possible extra planet in our solar system, likely of a size between Mercury and ...

Astronomers have discovered fresh evidence suggesting the possible existence of an unseen planet in the far reaches of our solar system.

"The profile of the occultation was most consistent with it being a new satellite — a new moon — going around Quaoar." ...

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 ...

Unusual shape of Fomalhaut's debris ring shows evidence of sculpting by ancient planets, rewriting story of planetary system evolution. (Nanowerk News) Astronomers using the Atacama Large ...

Astronomers have captured something extraordinary: the first-ever direct photo of a baby planet growing inside a dusty ring ...

When you buy through links on our articles, Future and its syndication partners may earn a commission. An artist's conception of Quaoar and its small moon Weywot. Not pictured are the dwarf planet's ...