Solar System

Our solar system consists of an average star we call theSun, the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.It includes: the satellites of the planets; numerous comets, asteroids, meteoroidsand the interplanetary medium. The Sun is the richest source of electromagneticenergy (mostly in the form of heat and light) in the solar system. The Sun'snearest known stellar neighbor is a red dwarf star called Proximal Centauri,at a distance of 4.3 light years away. The whole solar system, together withthe local stars visible on a clear night, orbits the center of our home galaxy,a spiral disk of 200 billion stars we call the Milky Way. The Milky Way has twosmall galaxies orbiting it nearby, which are visible from the southernhemisphere. They are called the Large Magellanic Cloud and the Small MagellanicCloud. The nearest large galaxy is the Andromeda Galaxy. It is a spiral galaxylike the Milky Way but is 4 times as massive and is 2 million light years away.Our galaxy, one of billions of galaxies known, is traveling throughintergalactic space.