The Solar System is far more diverse in size than it appears from Earth. From tiny rocky worlds to massive gas giants, each ...

“These two planets have densities comparable to a nice blob of shaving foam, fresh from the can,” Dr. George Dransfield said.

Two newly confirmed "super-puff" planets are so diffuse that they are less dense than cotton candy, despite being about the size of Jupiter. Their rare orbital relationship and enormous, ...

In a new study, a team of astrophysicists, including two researchers at CU Boulder, have discovered a small and rocky world orbiting a star far from Earth—similar to our own planet, perhaps, but ...

NASA’s Kepler mission has discovered the first Earth-size planets orbiting a sun-like star outside our solar system. The planets, called Kepler-20e and Kepler-20f, are too close to their star to ...

Five years ago, astronomers revealed a spectacular collection of other worlds: the TRAPPIST-1 system. Newspapers around the world printed the discovery on their front pages: Astronomers had found that ...