The Moon
The Moon is Earth’s only natural satellite—a rocky, cratered body about one‑quarter the diameter of Earth, orbiting at an average distance of approximately 384,400 km. It influences tides, stabilizes Earth’s axial tilt, and was formed about 4.5 billion years ago following a collision between Earth and a Mars-sized object.
Source: science.nasa.gov
APODs including "The Moon"
An Unexpected Asteroid Valentine
14/02/2000
Maybe the Moon owns our hearts, but this won't stop the occasional asteroid from sending us a valentine. Friday, to the surprise of many, the NEAR mission on approach to asteroid 433 EROS photographed what appears to be a heart-shaped depression. After NEAR reaches the asteroid today, NASA plans a series of maneuvers to make the robot spacecraft the first ever to orbit an asteroid. More detailed pictures will soon be taken of the 33 kilometer long asteroid EROS and this 5 kilometer long depression. Most likely, fortuitous lighting and viewing angles accentuate the apparent heart shape -- but don't tell the Moon.