To receive the same amount of starlight as Mars receives from our sun, a planet orbiting an M-type red dwarf would have to be positioned much closer to its star than Mercury is to the sun. Disclaimer: ...

The mysterious Oort cloud is the source of many of our solar system's comets, but astronomers still have no idea what it looks like. Now, new simulations may have given them a first glimpse. The Oort ...

From meteorites that impact Earth, to a moon that orbits backwards, to an imposter lurking in the asteroid belt, a variety of strange, wandering worlds are rewriting what we know – and even how we ...