Supermassive black holes rarely travel alone. Most large galaxies hide one at the center, and when galaxies collide, the two ...
By Will Dunham WASHINGTON, Feb 14 (Reuters) - Astronomers have observed a planetary system that challenges current planet formation theories, with a rocky planet that formed beyond the orbits of its ...
Since the 1990s, astronomers have found a handful of other dwarf planets in the belt, such as Eris and Sedna, along with ...