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. New research suggests that ...

Far from the bright glare of the Moon, a much smaller companion has been quietly keeping pace with Earth, looping around the Sun in a complex dance that only looks like a shared orbit from our vantage ...

The inner solar system may have formed differently from how we have long thought it must have. For decades, researchers have thought that the rocky planets formed from a single disc of dust and debris ...