A planetary system 116 light-years from Earth has a peculiar pattern. It could flip the script on how planets form, scientists say.

Gas giants are large planets mostly composed of helium and/or hydrogen. Although these planets have dense cores, they don't ...

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

Astronomers have spotted an unusual 'inside-out' planetary system where a rocky world seems to have formed far beyond the realm typically reserved for gas giants.

General relativity helps explain the lack of planets around tight binary stars by driving orbital resonances that eject or destroy close-in worlds. This process naturally creates a “desert” of ...

Relatedly, astronomers may have just pushed the upper size limit of what counts as a planet.

Most planet-forming disks have warps that can lead to planets on inclined orbits, which could explain where the tilt of Earth's orbit came from. When you purchase through links on our site, we may ...

This article was originally featured on The Conversation. Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A cloud of ...

The solar system may have a ninth planet after all. This one is 5,000 times bigger than outcast Pluto and billions of miles farther away, say scientists who presented "good evidence" for a ...

Stargazers, get ready for a celestial show! A planetary alignment featuring six planets will be visible in late February and ...

Jupiter, Mercury, Neptune, Saturn, Uranus, and Venus—will appear in the sky together in a special planet parade on Feb. 28.