Could a giant planet between Mars and Jupiter have doomed Earth? A new study suggests that small changes would have been ...

Lucy is preparing for a close encounter with the asteroid Donaldjohanson, a key milestone before its groundbreaking journey ...

YR4, which orbits the sun every four years and periodically crosses Earth's orbit. The nature of its orbit makes it a ...

The dinosaurs, of course, could do nothing about the killer asteroid, other than presumably waving their tiny arms at the oncoming doom. But if they did have a space program — and yes ...