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

A team of astronomers has identified a four-planet system orbiting the red dwarf star LHS 1903 that defies conventional expectations about how planets arrange themselves around their host stars. The ...

In A Nutshell Arrokoth, a snowman-shaped object billions of miles from Earth, is one of the oldest and least-disturbed relics of the early solar system Scientists have long debated whether its two ...

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

A research team led by University of Minnesota School of Physics and Astronomy Professor Yong-Zhong Qian uses new models and evidence from meteorites to show that a low-mass supernova triggered the ...