For centuries our solar system was the only planetary system known to humans. We had no proof other worlds existed beyond those in our own cosmic backyard, and we imagined that if other planetary ...

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit before shoving four of the solar system's planets onto a different course. When ...

Our solar system may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far into the solar system was touted more than a century ago. But ...

Add Yahoo as a preferred source to see more of our stories on Google. An artist's impression shows the "inside out" planetary system around the star LHS 1903. - ESA An exoplanetary system about 116 ...

When I was a kid, there were nine planets. Now we know of thousands! But that includes exoplanets, alien worlds that orbit alien suns. Only eight planets call our solar system home. Or there might ...

We’ve found lots of “habitable” worlds but we don’t know what factors are needed for life. There are lots of reasons to search for planets around other stars—exoplanets. A big one is to find other ...

The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have dubbed ...

The universe rarely makes things easy to understand. For decades, researchers thought they had the recipe for a solar system figured out. You put a star in the middle, scatter some rocky crumbs nearby ...

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. Planetary scientists are ...

'We're showing that, everywhere we look now, there was some sort of magnetic field that was responsible for bringing mass to where the sun and planets were forming.' When you purchase through links on ...

This article was originally featured on The Conversation. Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A cloud of ...