Asteroid 2017 AG13 unexpectedly whizzed by Earth on Monday. What is NASA doing to prepare?
Sponsored by the National Audubon Society, the annual winter tally offers an opportunity for ordinary citizens to help gather data on bird populations around the globe.
In an astronomical first, the Hubble telescope spies a shadow that appears to betray the presence of a hidden planet.
SpaceX has an ambitious timeline, but a more cautious approach may be necessary, some observers say, given how much is at stake.
Two stars in the binary star system KIC 9832227 may collide sometime in 2022, creating a red nova that would be visible to the naked eye some 1,800 lightyears away.