Surprised astronomers said Thursday they have discovered a star with planets in a bizarre order that defies scientific expectations -- and suggests these faraway worlds formed in a manner never seen ...

Their observations of a faint, cool M-dwarf star called LHS 1903 revealed a system with a rocky world at its outer edge. LHS ...

Astronomers have found a distant world that challenges planetary formation theory, with a rocky planet where gas giants should be.

For decades, our solar system was thought to have nine planets, with Pluto considered the smallest and farthest. But in 2006, Pluto was officially reclassified as a dwarf planet by the International ...