Stars passing close to the sun could cause planets to collide, including with Earth, or even be ejected as rogue planets, new simulations show. By Katherine Kornei If our species manages to hang on ...

There’s a bit of a paradox about our galaxy: it’s both jam-packed with stars and cavernously empty. The Milky Way is crowded in the sense that it holds hundreds of billions of stars, as well as ...

Mercury has long baffled astronomers because it defies much of what we know about planet formation. A new space mission ...