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

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

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

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 ...

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, ...

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

All of our solar system’s planets are lining up to parade through the night sky at once. This extraordinary celestial event ...

Tonight and throughout January, stargazers can see a planetary alignment in the night sky or what some are calling a ...

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

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

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