The chance of a planet forming in the outer reaches of the solar system - a hypothetical Planet Nine - could be as high as 40 ...

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

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

Based on 20 years of observations by NASA’s Hubble Space Telescope, new research sheds light on one of the solar system’s ...

Information about Uranus is limited. What we know is that the planet is composed mainly of water and ammonia ice, its diameter is about 51,000 kilometers, about four times that of the Earth, and its ...

There’s a new frozen oddball orbiting the Sun, and it’s not your average space rock. It’s a planet—a minor one, to be ...

There have never been so many satellites orbiting Earth as there are today, thanks in part to the launch of mega ...

A team of astronomers believe they may have discovered a new dwarf planet—just like Pluto—on the edge of our solar system.

Astronomers may have found a new candidate for the role of the ninth planet in the solar system.

B rocket is being fueled for launch of a complex deep-space mission targeting both a near-Earth asteroid and a comet.

The robotic Tianwen-2 spacecraft will collect samples from Kamoʻoalewa, which some scientists suspect is a fragment of the moon.

A small team led by Sihao Cheng, Martin A. and Helen Chooljian Member in the Institute for Advanced Study's School of Natural ...