It's an evocative idea that has long bedeviled scientists: a huge and mysterious planet is lurking in the darkness at the ...

U.S. astronomers hunting for "Planet Nine" have instead stumbled on what appears to be a new dwarf planet in the solar system's outer reaches.

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

Our moon is a particularly unusual example of moons when it comes to planetary bodies. Though many other planets in the solar ...

The object, named 2017 OF201, has a diameter of about 700 kilometers, according to a preliminary study - It is three times as ...

Astronomers find evidence of a possible ninth planet beyond Neptune, reigniting the debate about the formation of the Solar ...

Astronomers confirm the existence of small, hot and likely rocky planets by observing the subtle gravitational wobbles of the star they orbit Researchers supported by the U.S. National Science ...

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

An international team of astronomers claim to have discovered a 'super-Earth' that's bigger than our own blue planet but smaller than Neptune. A new paper, published in the journal, Science has ...

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

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 ...

Today, it’s believed that Jupiter and Saturn, the largest planets, were the first to fully form, both within a few million ...