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 ...

All seven of the other planets in our solar system are about to become visible at once in a great planetary alignment – ...

Stargazers will be treated to a dazzling six-planet "alignment" this January.

Starting up again Saturday, a sweeping view of our solar system will glow in the night sky. The planetary alignment, or a ...

Baker said that there are other astronomical events that may be more interesting than the parade of planets. Baker said Mars ...

Beyond Neptune lies the Kuiper Belt, a vast expanse of icy bodies that may hold clues to the solar system’s formation. These ...

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

Ever since Isaac Newton famously talked about gravity, its dominance as a force in our solar system has been well known. It's ...

In the depth of winter, a sweeping view of our solar system will glow in the night sky. In total six planets will be visible, ...

Although it's being mistakenly promoted as a "rare planetary alignment," one of the best "planet parades" in half a century ...

In the early evening, look to the southwest and you'll see Venus (the brightest object in the sky after the Sun and Moon) and ...