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

Stargazers will be treated to a rare seven-planet alignment in February. This is what scientists hope to learn.

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

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.

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

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

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

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

A new study suggests that a planet-sized object may have passed through the solar system billions of years ago.

A rare celestial event is captivating stargazers as six planets align in a striking display, says Professor Chandana ...