Bode’s Big Night. On December 31, 1774, Johann E. Bode discovered both M81 and M82. In 1779, Pierre Mechain independently ...

Astronomers have long known the universe is expanding—but exactly how fast remains one of the biggest mysteries in cosmology. Different techniques for measuring the Hubble constant stubbornly disagree ...

Created by the solar wind — a stream of charged particles constantly pouring out from the sun — the heliosphere acts as a ...