Watch 2 Russian cosmonauts perform a spacewalk outside the International Space Station (ISS) on Wednesday, May 29.

Citizen scientists: NASA’s OSIRIS-REx mission needs your help choosing its sample collection site on asteroid Bennu ... and your extra eyes to look for whatever else might be interesting.

A new survey algorithm - called Transit Least-Squares - has just caused the number of known, rocky, Earth-sized worlds orbiting distant stars to grow again, as astronomers add another 18 exoplanets to the list.

It wasn't visible to the eye, but some telescope users in Earth's Southern Hemisphere caught it at its May 25 closest approach. Now Northern Hemisphere observers will get their chance. Charts here, and check out this cool video!

It's amazing we can detect comets in distant solar systems at all! These are the first 3 exocomets found in data gathered by TESS, NASA's newest planet-hunter. The comets orbit the famous star Beta Pictoris.

What happens when young stars brush past each other? A lot, according to a new study suggesting our solar system contains comets stolen from another star 4.5 billion years ago.

"Here is the video I shot, be prepared to be mind-blown!" Marco Langbroek wrote on his website SatTrackCam Leiden (b)log, where he shared an amazing capture of dozens of SpaceX Starlink internet satellites chugging along, in a straight line, across the heavens.

Want to send your name to Mars on NASA's next rover mission in 2020? You'll get your name etched on a microchip affixed to the rover - and a souvenir boarding pass. Here's how.

Does Pluto have an ocean? That idea seems preposterous at first, but a new study adds to the growing evidence for a subsurface ocean on this distant dwarf planet ... and explains how it stays liquid.

New research suggests that a wayward dwarf planet collided with the moon in the early history of the solar system, causing the stark difference between the moon’s heavily-cratered far side and the lower-lying open basins of its near side.