A U.S. scientist searching for a civilization across 7 Earth clones circling the red dwarf star TRAPPIST-1 says its own alien ...

The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

Planets with suns like Wolf 359 are subject to huge blasts of radiation that raise questions about their long-term ...

When astronomers found a large world farther out than Pluto, it became one of the final nails in the coffin of our ninth ...

Hubble Space Telescope observations of white dwarf star G238-44 has shown that it is "consuming both rocky-metallic and icy ...

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit ...

The enormous visitor to our solar system may have been about 8 times the mass of Jupiter, and come nearly as close to the sun ...

An object we thought belonged to the most common category of planet in the galaxy has turned out to be something we've never seen before. The exoplanet Enaiposha, or GJ 1214 b, is a hazy world ...

Astronomers discovered the exoplanet in 2016, a gas giant that’s slightly larger than Jupiter with a fraction of its mass, ...

A Triple Star System Yields an Unusual Surviving Star Unlike our Sun, which exists alone, at least half of the stars in our ...

Stargazers will be treated to a dazzling six-planet "alignment" this January.