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 ...

The enormous visitor to our solar system may have been about 8 times the mass of Jupiter, and come nearly as close to the sun ...

Our Solar System is a carefully balanced celestial dance held together by a virtually perfect balance of gravity and inertia.

NASA has found something on Uranus and Neptune. The ice giants of the solar system have long been enigmas for science.

Especially since all seven of the other planets in our solar system are about to become visible at once in a great planetary ...

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

A new study claims it is possible an "alien visitor" could have warped our solar system during its earliest years.

While the planets are technically always "aligned" along the same plane in our sky, seeing so many at once is a special ...

Worlds will align for a "planetary parade" in January, with four bright and easily visible to the naked eye. But an even ...

While the planets won’t be perfectly aligned, their placement will follow the orbital plane of our solar system. Which planets are parading in January and February? The January planetary ...