Planet 9 sits at the edge of scientific imagination, promising either an epic expansion of the Solar System or a lesson in how easily patterns can mislead us. As new data arrive and old assumptions ...

Add Yahoo as a preferred source to see more of our stories on Google. When you buy through links on our articles, Future and its syndication partners may earn a commission. A new discovery may mean ...

Debate has raged for two decades over whether Pluto should be considered a planet. Some want President Trump to take action ...

"It's very rare to discover an object both large and with an exotic orbit." When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Breaking space news, ...