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

Add Yahoo as a preferred source to see more of our stories on Google. Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky ...

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 ...

LHS 1903 flips rock and gas on their heads, hinting that late-born planets can rewrite the rules around common red dwarfs for now.

A newly studied solar system breaks the usual planet pattern, raising fresh questions about how rocky and gas planets form.

(The Conversation is an independent and nonprofit source of news, analysis and commentary from academic experts.) Curious Kids is a series for children of all ages. If you have a question you’d like ...