The moon is 3,476 kilometers in diameter, one quarter of Earth's diameter. Temperatures vary from 130--180 degrees Celsius.
Creation: By the collision-ring theory, the moon was created 4.5 billion years ago when a planet-sized object collided with Earth. Materials were thrown into orbit around Earth, where it formed a ring. Gravity caused the material to combine.
Maria: The dark, flat areas on the moon are called maria. The maria are hardened rock formed from lava flows 3-4 billion years ago.
Marias on the Moon
A Moon Crater
Craters: Craters, large round pits, were created by the impacts of meteoroids, chunks of rock from space. Craters were formed earlier than marias.
Highlands: The light colored features on the moon's surface are highlands, mountains. The peaks created dark shadows, visible to the telescope. Lunar highlands cover most of the moon's surface.