The six planets were visible in the days immediately leading up to Jan. 21, and for about four weeks afterward. Mars, Venus, Jupiter and Saturn should be visible to the naked eye. You'll need a ...

A planet parade is when several of our solar system's ... same side of the sun all right next to each other. The planets can never fully line up exactly like you see in pictures, but they can ...

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

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

The so-called 'planetesimal belts' are filled with tiny millimeter-sized particles created by collisions between comets.