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

Mercury joins the night sky to complete a 7-planet alignment just after sunset for the end of February. Saturn leaves our ...

Venus, Jupiter, and Mars dominate the sky. Catch your last views of Saturn as early in the month, the Moon passes in front of ...

February brings a rare planetary parade, with five bright planets in clear view and a special alignment of Mercury and Saturn ...

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

When astronomers found a large world farther out than Pluto, it became one of the final nails in the coffin of our ninth ...

Mars, Venus, Jupiter, and Saturn should be visible to the naked eye. The six planets will be visible until February 9. You'll ...

Starting at 12:30 p.m. ET (1730 GMT) on Saturday (Jan. 25), astrophysicist Gianluca Masi of the Virtual Telescope Project ...

Four planets will be in the parade in January, while seven will align in February. Here's how to see the events.

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

While claims of a “rare alignment” are overblown, you can still see up to six planets in the night sky this weekend. Here's ...