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' ...

Jupiter is an enormous gas giant, more massive than all the other planets in the solar system combined... and yet small compared to our Sun and other Stellar Objects. Could Jupiter be turned into a ...

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

Saturn may be difficult to see since it will be near the sun, according to StarWalk. It's not especially remarkable for a few ...

The system is believed to be traveling at least 1.2 million miles per hour (1.93 million kilometers per hour), according to a ...

Like a celestial parade across the cosmos, five bright planets are lighting up the night sky and visible with the naked eye ...

While the composition of gas and dust in a molecular cloud is fairly uniform, everything changes once a star begins to form.

"With an orbital period of 570 days, it is a relatively cold gas giant planet," said Guðmundur Stefánsson of the University ...

Known as the "Parade of Planets," the celestial event will feature appearances from Mars, Jupiter, Uranus, Venus, Neptune and ...

In August 2006, the International Astronomical Union made the controversial, but correct, decision to demote Pluto from its ...