The enormous visitor to our solar system may have been about 8 times the mass of Jupiter, and come nearly as close to the sun ...

All seven of the other planets in our solar system are about to become visible at once in a great planetary alignment – ...

A powerful new tool comes online this year that could help astronomers locate the mysterious planet hiding somewhere beyond ...

A nearby star that may host a planet or two could provide a clue about whether planets orbiting the smallest stars can ...

The planet, dubbed Haumea, orbits the ... of known dwarf planets beyond the orbit of Neptune, which with the other so-called giant planets—Saturn, Uranus and Jupiter—all have rings.

There are eight official planets (sorry, Pluto) in our solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. But astronomers have spent the better part of a century wondering ...

The Carnegie Institution for Science and the International Astronomical Union’s Minor Planet Center has announced the discovery of dwarf planet ... For comparison, Earth orbits 1 AU (93 million ...

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

While Charon is currently listed as a satellite or moon by the International Astronomical Union (IAU), consideration is being given to it perhaps being classified as a dwarf planet in its own right, ...

The planet, called Barnard’s b, orbits Barnard’s star ... Barnard’s star is a red dwarf star, a low-mass, cool star that comprises about 70% of all the stars in the Milky Way.