The Galileo spacecraft sent back this image of the Moon as it headed into the outer solar system. The distinct bright ray crater at the bottom of the image is the Tycho impact basin.

Earth's Moon in Brief
Our moon makes Earth a more livable planet by moderating our home planet's wobble on its axis, leading to a relatively stable climate, and creating a rhythm that have guided humans for thousands of years. The Moon was likely formed after a Mars-sized body collided with Earth and the debris formed into the most prominent feature in our night sky.

Featured Mission: LADEE
LADEE will help determine the impact of increased human activity on the Moon's thin exosphere. If scientists are ever to know the lunar atmosphere in a relatively natural state, now is the time to look.

Read More About Earth's Moon