A planetary system 116 light-years from Earth has a peculiar pattern. It could flip the script on how planets form, ...

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

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

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 ...

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 ...

A closer look at the planets around a star called LHS 1903 may just flip our understanding of how planetary systems form.

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

Astronomers have found a compact solar system whose planets line up in a way that, according to current models, should not be possible. Around the small star LHS 1903, a dense rocky world orbits on ...