A compound lens forged by two galaxies is helping astronomers get a bead on the Hubble Constant and dark energy.

The Arecibo Message as it appears when its 1,679 bits are properly aligned on a grid (left), an annotated illustration ...

For spinning spheres, centrifugal force is maximized at the equator, where the rotational speed is highest. The amount of the ...

The Full Super Moon occults the Pleiades, the ice giant Uranus reaches opposition, and the Leonid meteor shower peaks in the ...

New research sheds light on how a pair of unusual black holes may have been able to keep their companion stars alive — and at a distance.