Astronomy

Extraterrestrial life doesn’t need to be intelligent to be worth finding.

One question for Paul Sutter, a theoretical cosmologist at Stony Brook University.

One question for Joseph Silk, an astrophysicist at Johns Hopkins University.

The defining problem in the search for ET.

Early scientists didn’t know it, but we do now: The void in the universe is alive.

There was a lot more to this year than stunning images.

A recent gamma-ray burst known as the BOAT—“brightest of all time”—appears to have produced a high-energy particle that shouldn’t exist. For some, dark matter provides the explanation.

With one small error or manipulation, cosmic interference would spell disaster.

First the oceans boil off. Then things really get serious.