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 ...

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

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

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

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

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

Six of our cosmic neighbors are expected to line up across the night sky tonight, in what has been dubbed a "planetary parade ...

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, ...

Simpson and Chen ran mathematical models looking at how differently sized Earth-like worlds would have affected the rest of ...

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

Plate tectonics give Earth its mountains, earthquakes, continental drift and maybe even helped give rise to life itself. But ...