Rethinking Galaxies
Edwin Hubble's tuning-fork diagram has helped astronomers classify galaxies for more than 70 years. But recent research shows that it might be time for a makeover — to a "comb" diagram.
A Case for Frozen Hydrogen
Can hydrogen freeze solid in interstellar clouds? If so, it might contribute to a mysterious form of interstellar light absorption.
IceHunters: A Kuiper Belt Search
In the latest citizen science project, you can help NASA hunt new objects in the Kuiper Belt — and perhaps even steer the New Horizons probe toward your lucky find.
Black Hole Gobbles Star
A powerful Gamma Ray Burst captured by the Swift space telescope earlier this year gives astronomers a unique chance to study tidal disruption.
The Earliest Black Holes
Combining data from the deepest images ever taken in visual/infrared wavelengths and X-rays, astronomers have discovered some of the earliest black holes in the universe.
Oddball Stars in the Milky Way's Heart
The first blue stragglers identified in the Milky Way’s bulge pose a question: why do they look so young?
Video: Remarkable Explosion on the Sun
After three years of minimal activity, the Sun has come alive. This video of a 3-hour eruption earlier today beats anything you've seen.
The Milky Way’s Fraternal Twin
The face-on spiral galaxy NGC 6744 has long been touted as the Milky Way’s twin. But, though a close match, these two star systems are not exactly identical.
When Galaxies Collide
Images from the Spitzer Space Telescope and GALEX make it possible for scientists to imagine what the Milky Way-Andromeda crash might look like five billion years from now.
More Ado about the Cas A Supernova
Legend has it that a bright noon star graced the birth of the 17th century British Monarch Charles II. Could it have been a daytime glimpse of the Cas A supernova?
Dissecting Saturn's Big Storm
Scientists have combined images from Cassini and big telescopic eyes in Chile to understand Saturn's massive storm in ways never before possible.
Vesta Ahoy!
As Dawn closes in on Vesta, pictures from the spacecraft’s cameras are helping engineers steer it to its July rendezvous.
Gravity Probe B: Relatively Important?
It took five decades and $750 million for the Gravity Probe B mission to check, once again, that Einstein’s theory of general relativity is right. Was it worth it?
The Hottest, Densest Super-Earth Yet
Two research teams combine forces to study the wildest exoplanet yet identified.