A new dwarf planet, discovered beyond Neptune and described as Pluto's 'cousin,' could void the hypothesis of a Planet X in ...

Their telescopes, on the ground and in space, tend to focus on planets much larger than Earth, in part because they're easier ...

Scientists with NASA announced they have discovered an Earth-sized planet that is likely rocky – and could be habitable. The planet, named TOI 700 e, is slightly smaller than Earth and ...

A second, smaller planet might be nearby that measures only slightly bigger than Earth and it, too, might dwell inside the “conservative” habitable zone, NASA reported, saying the planet ...

Astronomers have discovered that the flattened clouds of gas and dust around stars — nurseries that give birth to planets — are generally smaller than previously thought. Some are so small, in ...

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. Two teams of ...

Earth is the only planet known to support life. Learn about what Earth is made of and where it came from. When you purchase through links on our site, we may earn an affiliate commission.

The lone planet confirmed to be in the system is squeezed in between the two, orbiting at a distance similar to Earth's ...

Astronomers have discovered that the Jupiter, the largest planet in our Solar System, was once so big that it could have held ...

The three other potential planets orbiting Barnard's star all apparently are rocky and smaller than Earth, ranging from 20-30% of Earth's mass. The hope is that at least one of these may be in the ...

A massive "planet killer" asteroid will make ... a hazard 2011 UL21 is likely at least 10 times smaller than the largest space rock to ever hit Earth, the Vredefort asteroid, and around five ...