New research reveals that some black hole collisions may cascade, with the dense objects crashing into one another to create even more-massive black holes.
On April 30, after more than 20 years in space, NASA's Rossi X-ray Timing Explorer ( RXTE ) satellite re-entered and burned up in Earth's atmosphere.
Comet 67P/Churyumov-Gerasimenko may have survived multiple impacts on the way to forming its peanut shape.
Alien civilizations with technology on a par with humanity's could be detectable using today's instruments. A new study suggests that if geostationary satellites are thick enough around an alien world, they could be spotted with telescopes already hunting for undiscovered planets.
Mars may have gained its two tiny moons after an asteroid-size object slammed into the surface of the Red Planet.
While telescopes in space can scan the sky without interference from Earth's clouds, they still run into problems from hazes on other planets.
Growing patches of ice and minerals associated with liquid water reveal that the dwarf planet Ceres is still evolving.
A big clue about the nature of mysterious dark matter may have been discovered.
Last summer, scientists announced that they had found what could be the first moon to be spotted outside of the solar system.
Jupiter's Great Red Spot has swirled for hundreds of years, but the source of its distinctive color remains a mystery.
Supermassive black holes may provide the key to understanding some of the most energetic particles in the universe.
NEW ORLEANS — The dwarf planet Ceres' famous bright spots suggest that the gray, crater-laden world is surprisingly active, a new study reports.