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

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

Mercury, the closest planet to the Sun, completes an orbit – a year for the planet ... Astronomers use alignments to probe ...

A super-Earth planet that dips in and out of its star's habitable zone has been discovered just 19.7 light-years away.

Our sun and its planets arose when the universe was about 9 billion years old, and the oldest known planet developed 1 billion years into the life of the universe. Receive a weekly dose of ...

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

Thirty years after the discovery of the first exoplanet, we detected more than 7000 of them in our Galaxy. But there are ...

A planet that may support alien life has been discovered less than 20 light-years away from Earth - and it's believed to ...

This occurs when the planets' positions in their elliptical orbit around the sun line make them seem like they are close ... However, it’s easier if you surrender to the universe at this time. Not ...

Sky watchers are in for a treat this month as the stars align to give amateurs a shot to see six planets at once.

Six planets grace the sky this month in what's called a planetary parade — Venus, Mars, Jupiter and Saturn are visible to the ...