Southwest Research Institute scientists propose a new model for the formation of compact exoplanetary systems that contain multiple rocky planets in tight orbits around their star. In this model, ...

Studying the orbits of thousands of exoplanets shows that large planets tend to have elliptical orbits, while smaller planets tend to have more circular orbits. This split coincides with several other ...

The shape of a planet's orbit is one of its fundamental properties, along with its size and distance from its host star. Earth has a nearly circular orbit, but some planets outside our solar system, ...

EVANSTON, Ill. — Except for the fact that we call it home, for centuries astronomers didn’t have any particular reason to believe that our solar system was anything special in the universe. But, ...

Planets are bodies that orbit a star and have sufficient gravitational mass that they form themselves into roughly spherical shapes that, in turn, exert gravitational force on smaller objects around ...

Astronomers have uncovered a distant planetary system that flips a long-standing rule of planet formation on its head. Around the small red dwarf star LHS 1903, scientists expected to find rocky ...

As planetary systems evolve, gravitational interactions between planets can fling some of them into eccentric elliptical orbits around the host star, or even out of the system altogether. Smaller ...

In 1995, the discovery of 51 Pegasi b, a massive planet orbiting its star closely, revolutionized astronomy. This finding ...

Nearly a decade after astronomers first proposed that a massive, unseen world is warping the paths of the most distant known ...