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 ...

In humanity’s millennia of staring at the stars and decades of launching probes to explore our universe, only two spacecraft carrying working instruments have ever managed to escape the bubble of ...

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 ...