Our Milky Way had a pretty sizable sibling long ago — until neighboring Andromeda tore the unfortunate galaxy apart, a new study suggests.
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 European Gaia spacecraft recently released a catalog of the positions of 1.7 billion stars, mapping our stellar neighbors around the Milky Way with unprecedented precision.
Astronomers in Australia are eager this week for a special celestial alignment that could tell them more about one of the most intriguing candidates for hosting life beyond Earth.
A newfound quasar is blasting out the brightest radio emissions ever observed in the early universe, new research reports.
A sausage-shaped galaxy smashed into our own Milky Way billions of years ago, changing our galaxy's shape forever.
A stunning, first-of-its-kind photo shows a giant alien world taking shape in the disk of gas and dust surrounding a young star.
Japanese astronaut Kimiya Yui took some stunning photos of constellations during his first trip to the International Space Station in 2015.
For the first time, astronomers have discovered a galaxy cluster that was hiding in plain sight, not far from the Milky Way.
A rare, midsize black hole has been spotted as it devours a star. Intermediate-mass black holes are typically challenging to spot; the new finding is the best observation to date.
A new study validates Einstein's theory of general relativity in a distant galaxy for the first time.