Scientists have found the first evidence of water vapor on Ganymede, Jupiter's largest moon, bringing us insights into the habitability of other worlds.
Researchers in the UK have found that neutron-star mountains are less than a millimeter tall. These dense, dead stars are nearly perfectly smooth spheres.
A Jupiter X-ray aurora mystery has perplexed astronomers for decades. Now they think ions responsible for the X-rays "surf" electromagnetic waves into Jupiter's atmosphere.