South-West Iceland's Been Hit by 17,000 Earthquakes This Week. It May Be About to Erupt

If you summitted the Andes 20 million years ago, you might have looked out on a glinting inland sea, big enough to sail from Paraguay to Venezuela. Here's the story of that waterway and the rainforest biodiversity that may be its legacy.

Earth has a hot new neighbor -- and it's an astronomer's dream

One and Done: Why People Are Eager for Johnson & Johnson’s Vaccine