The universe is expanding 9 percent more quickly than expected, telling us there’s something we’re missing. Could it be a new type of particle?

Mars’ largest moon, Phobos, is slowly falling toward the planet, but probably won’t smash into the red planet’s surface.

Hundreds of thousands of years of volcanic eruptions in India—accelerated by a massive asteroid impact 66 million years ago—may have caused a perfect storm that led to the extinction of dinosaurs and other animals.