Dark matter affects how stars move within galaxies, how galaxies build up over time, and how everything in the universe is held together—but no existing tool has directly detected it. While dark ...

A computer simulation shows how two neutron stars of unequal mass merge, form a black hole and spit out a jet of high energy matter.

When is the first day of summer? Find out all the facts about the longest day of the year! When is the first day of summer in ...

A cloud of energetic gas lit up by a collision of galaxies spans nearly 20 million light-years, leading astronomers to ...