NASA has been monitoring a never-before-seen planet in its solar system, which is eight times the size of Earth. The ...

Mercury takes only 88 Earth days to orbit the sun.

Stargazers will be treated to a dazzling six-planet "alignment" this January.

But that includes exoplanets, alien worlds that orbit alien suns. Only eight planets call our solar system home. Or there might still be nine if some astronomers are correct about an as-yet ...

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

The solar system consists of 8 planets, including Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Each planet has its own unique characteristics, such as size, composition ...

The exoplanet has a radius around 2.7 times and a mass about 8.2 times greater than Earth ... expands our understanding of the diversity of planets (just like this strange object in our Solar System).

While claims of a “rare alignment” are overblown, you can still see up to six planets in the night sky this weekend. Here's ...

Mars, Venus, Jupiter and Saturn should be visible to the naked eye, but get a telescope and you can spot Neptune and Uranus.

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.

Mars, Venus, Jupiter, Saturn, Uranus and Neptune will appear together in a row throughout the start of February – although Neptune and Uranus will only be visible with binoculars or a telescope.