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

The building blocks of life could have been delivered to Ceres by one or more space rocks from the outer asteroid belt.

Earth is home to some truly bizarre and breathtaking landscapes — here are 20 that look straight out of an alien world.

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

A suspected planet that appears well-suited to life has had its existence confirmed – and it’s very much in our neighborhood, ...

Kepler was one of the most successful exoplanet-hunting missions so far. It discovered 2,600 confirmed exoplanets—almost half ...

Continent-size islands deep inside Earth's mantle could be more than a billion years old, a new study finds.

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit before shoving four of the solar system's planets onto a different course.

The data used to create the image is from a Hubble Space Telescope project to capture and map Jupiter's superstorm system.

Nobody knew what they are, and whether they are only a temporary phenomenon, or if they have been sitting there for millions ...

An object we thought belonged to the most common category of planet in the galaxy has turned ... So-called mini-Neptunes can be of a similar size, but their composition is significantly different, ...