Mercury takes only 88 Earth days to orbit the sun.

Filmmaker Adam Nemoy helps celebrate the 90th anniversary of Pluto's discovery this month at the 6th annual 'I Heart Pluto' ...

Mercury joins the night sky to complete a seven-planet alignment just after sunset for the end of February. Saturn leaves our ...

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

According to a recent YouGov poll, 35% of Americans think Pluto is not a planet. But they are all wrong—kind of. To get to ...

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

While planets circle the sun in what's called and heliocentric orbit, they rarely fall together in what appears to the human ...

Witness a rare celestial spectacle as seven planets align in the night sky for one night in late February, offering a ...

The formation of our solar system from a singular nebula raises an intriguing question: why did each planet develop with a ...

AN alien world “suffers star-grazing torture” every 111 days as its fiery sun boils the planet to a hellish 1,093C. This ...

Six planets are parading across the sky, appearing as some of the night's brightest stars. A few easy tips can help you ...

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