On January 5, 2005, astronomers at NASA discovered Eris, the second-largest dwarf planet in the solar system. Eris is just ...

With sapphire waterfalls, lava rain and orbits around dead stars, these distant worlds push the limits of what’s possible.

The star system V1298 Tau reveals that many planets begin as large, low-density worlds that slowly shrink and shed their ...

NASA’s Kepler mission has verified 1,284 new planets – the single largest finding of planets to date. “This announcement more than doubles the number of confirmed planets from Kepler,” said Ellen ...

Planets larger than Earth but smaller than Neptune are the most common kind in the galaxy, but because our solar system lacks such a planet, scientists don’t know much about how they form. Astronomers ...

On Feb. 28, a stellar alignment of planets will illuminate the night sky for the last time in a decade Space Frontiers/Hulton Archive/Getty Calling all stargazers and astronomy enthusiasts — something ...

It is a question that feels like it should have a straightforward answer: how many planets are there in our solar system? Since Pluto was relegated back down to dwarf planet status, almost everyone ...

A rare celestial event on Feb. 28 will offer skywatchers the chance to witness a "planet parade" of all seven planets in our solar system outside of Earth. It's the last time this type of planetary ...