Astronomers have spent years searching for a possible hidden giant planet far beyond Neptune. Unusual orbits among distant ...

(Ianm35/iStock/Getty Images Plus) The Solar System is one of the comforting constants of human existence. No matter what else ...

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, ...

Key science: Stellar dynamics, N-body simulations, planetary orbital stability, and galactic gravitational potentials.

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 ...

Jupiter, Saturn, Uranus and Neptune did not always have their current positions in the solar system. According to the ...

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 ...

Our solar system may have hosted up to six giant planets in its first hundred million years, a new study suggests. The ...

OK, first, let’s get the name out of the way. Scientists have cataloged this exoplanet as PSR J2322-2650 b. It’s called that because it orbits a pulsar (a rapidly rotating neutron star) designated PSR ...

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, ...