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, ...

Jupiter, Saturn, Uranus and Neptune did not always have their current positions in the solar system. According to the planetary-instability model, they were born a little closer to the Sun and closer ...

We usually think of our Solar System as a calm, well-organized family of planets, but a new study suggests its early days may ...

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 ...

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 hunt for Planet Nine continues as new discoveries make the Solar System’s biggest mystery even harder to solve. Is there ...

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 ...