The monster collision between our Milky Way and fellow spiral galaxy Andromeda will occur about 4.5 billion years from now, rather than in 3.9 billion years.
Stars are giant, luminous spheres of plasma. Galaxies consist of stars, stellar remnants, dust, gas, and dark matter, bound together by gravity. Learn more about stars and galaxies.
The Hubble Space Telescope has discovered a dwarf galaxy in our own cosmic backyard, a mere 30 million light-years from the Milky Way.
NASA's Hubble Space Telescope captured a stunning new view of a spiral galaxy that wandered too close to the massive Coma galaxy cluster and is being stripped of its gas.
NASA's Parker Solar Probe has completed its first loop around the sun and entered the second of 24 planned orbits.
The far outer solar system is teeming with mountain-size space rocks left over from the long-ago planet-formation period, a new study suggests.
One of the Hubble Space Telescope's most famous images peered even deeper into the cosmos than scientists had thought.
We now have a better idea of how big black holes were born in the early universe, a new study reports.
Astronomers barely know anything about dark matter, but now they know this: It behaves differently in old, dying galaxies than in new, star-forming ones.
The superdense stellar corpses known as white dwarfs solidify into crystal spheres over time, a new study suggests.
Our Milky Way galaxy will endure more than one dramatic collision in the foreseeable future, new research suggests.
Brown dwarfs are cooler than stars but hotter than planets, and despite the name, they're not even very brown.
For hundreds of years the Small Magellanic Cloud has provided astronomers with a relatively close-up view of another galaxy.
NASA released a stunning new comparison photo to celebrate the anniversary of the first astronaut mission to repair the Hubble Space Telescope's blurry vision, 25 years ago.
NASA's Kepler space telescope captured the light of a stellar explosion that occurred about 170 million years ago.