SUNSET: 
Amateur Astronomers Reveal Long-Ago Galaxy Mergers
The images from five Brazilian amateur astronomers have captured Hubble-level details in galaxies, laying the ground for future work in understanding their histories. Want to join the fun?
Our Tiny Galactic Neighbor Hosts Ancient Stars
New observations show ancient stars lining the edges of the ultra-faint dwarf galaxy Tucana II, a tiny satellite of the Milky Way.
Astronomers Spot Galaxies Clustering in Early Universe
Astronomers have discovered a cluster of galaxies coming together just 770 million years after the Big Bang.
What New Horizons Found in Deep Space — And Why It Matters
NASA’s mission to the outer solar system has found more light than expected. That could mean more galaxies in the visible universe than we thought— or less, depending on who you talk to.
Astronomers Find Most Distant Gamma-ray Burst Yet
From the farthest-known galaxy in the observable universe comes the brightest and most energetic of events: a possible gamma-ray burst.
Astronomers Discover Galactic “Fossil” Inside the Milky Way
Thousands of stars that once belonged to an ancient galaxy are inside our own.
A Dark Matter-less Galaxy, Explained (Maybe)
An international team of astronomers has explained the lack of dark matter in a distant dwarf galaxy — another galaxy stole it.
Star Clusters Reveal the "Kraken" in the Milky Way's Past
Astronomers have reconstructed the Milky Way's merger history, finding that our galaxy has absorbed five large satellite galaxies in the last 12 billion years.
60-second Astro News: Mature Infant Galaxies & A Possibly Rogue Planet
This week in astronomy news: Distant galaxies that look older than they are and a terrestrial planet that might be drifting through our galaxy.
Astronomers Chart Star Formation History, Glimpse Fate of the Universe
Astronomers have tallied how star-making material evolved over cosmic time — and they've predicted how long stars will keep forming before the universe goes dark.
Hubble Images Reveal Dark Matter Problem
Astronomers studying Hubble Space Telescope images of massive galaxy clusters have uncovered a potential problem with dark matter.
Astronomers Map Andromeda’s Halo
Astronomers have observed 43 quasars in back of our sister galaxy, Andromeda, using the distant beacons to map its halo of hot gas.
See the Invisible: A Gallery of Magnetic Fields
Magnetic fields affect everything from star formation to galaxy evolution. View a gallery of images that show magnetism's role.
"Dead Ringer" for the Milky Way Found in Early Universe
A cosmic magnifying glass has revealed a Milky Way-like galaxy in the early universe that doesn’t conform to cosmologists’ expectations.
Remains of an Ancient Star Cluster Revealed
A torn-apart globular cluster provides a window into the Milky Way's past.
The 10 Million-Degree Gas Around the Milky Way
New observations show ultra-hot gas around the Milky Way. Stellar explosions may have driven this gas out of our galaxy.
Galaxies Are Even Bigger Than You Think
Galaxies swim in hot gas that extends much farther out than their stars — and plays an important role in the galaxy's evolution.
Rotating Disk in Early Universe Explains Galaxy Formation
The discovery of a stably rotating disk galaxy in the early universe is the best indicator yet for how galaxies like the Milky Way formed.
Vast Magnetic "Strings" Puzzle Astronomers
New observations have revealed plasma strung along vast magnetic "strings" crossing hundreds of thousands of light-years.
The Knife Edge Galaxy Throws Astronomers For a Loop
A 2008 image captured a stunning double loop of stars around an edge-on galaxy. Now, astronomers are questioning whether one of those loops exist.
