Hidden Stars Reveal Early Galaxies Were Far Bigger Than We Thought

Some of the earliest massive galaxies in the universe may be hiding enormous numbers of small, faint stars, suggesting they contain much more mass...

One Giant Asteroid Impact May Have Reshaped Mars’ Tiny Moon Deimos

A single asteroid impact may have dramatically reshaped Deimos, the smaller of Mars' two moons, creating both a huge depression near its south pole...

Dying Galaxies Reveal What Happens After Black Hole Jets Switch Off

Astronomers have discovered a group of faint "dying" radio galaxies that could change our understanding of what happens after supermassive black holes stop producing...

Mars Dust Could Threaten Astronauts’ Lungs, NASA Warns

Future astronauts exploring Mars will face a danger that may be much harder to avoid than extreme cold or radiation: dust. NASA has released a...

Hubble Discovers a Lost Galaxy Swallowed by the Milky Way 11.8 Billion Years Ago

The Milky Way has not always been the enormous spiral galaxy we see today. Like many large galaxies, it grew partly by swallowing smaller...

Scientists Solve Key Mysteries Behind Supernovae and X-Ray Bursts

Scientists have made two important nuclear measurements that could help explain what happens inside some of the most powerful explosions in the universe. In two...

Galactic archaeologists find stars in the Milky Way came from another galaxy 12 billion...

Look up on a dark night and the Milky Way appears as a calm band of stars across the sky. But our galaxy has...

Astronomers Discover a Mysterious New Object Called a ‘Black Hole Star’

Astronomers may have discovered an entirely new kind of object in the early universe: something that looks like an enormous star but is powered...

Giant Planets May Be Born in the Shadow of Supermassive Black Holes

Black holes are often imagined as cosmic vacuum cleaners that simply swallow everything nearby. But new research suggests the environment around supermassive black holes may...

Why Astronauts Get Constipated in Space: Their Blood Offers a Clue

Constipation is a surprisingly common problem for astronauts living in space. Scientists have long known that digestion can change when people leave Earth, but exactly...