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

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

Six of our cosmic neighbors are expected to line up across the night sky tonight, in what has been dubbed a "planetary parade". Throughout much of January and February, Venus, Mars, Jupiter, Saturn, ...

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

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

Five of the brightest planets will be visible to the naked eye. With help, you may even spot Uranus and Neptune.

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

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

This provides another piece of the puzzle to understand how planets and ... Pluto-Charon Formation Scenario Mimics Earth-Moon System ... a clearer picture of how the outer solar system formed ...

A shortcut for New Yorkers to spot some of the planets is to look for them when they are near the moon. On Feb. 1, Venus will ...

Look to the southwest sky after sunset on Saturday, as the sliver of a waxing crescent moon nears bright Venus with Saturn ...

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.