SpaceProdigal gas cloud was born in Milky Way and is crashing back in Smith's Cloud seemed to be an intergalactic gas cloud or even a starless galaxy. But now Hubble hints it's actually material from the Milky Way returning home News
SpaceOur moon would be a planet under new definition of planethood When astronomers last redefined "planet", Pluto was demoted to being a dwarf. A proposed revision to the criteria would instead grant planethood to the moon News