The moon is the second largest heavenly body as viewed from Earth. That's because it is so close: a mere 384,400 km away. If the moon were in an independent orbit about the sun, we would have no problem calling it a planet. At 3750 km in diameter, it is almost the size of mercury and a bit bigger than Pluto.
The moon is a desolate, hostile place. It has absolutely no atmosphere to speak of, and temperatures are cool: an average of -153O C and as cold as -233O C during a long (2 weeks!) lunar night. Yet the moon has resources. The moon is 40% oxygen by weight...one need only heat some moon rocks to extract this precious gas. And in 1997, NASA's Lunar Prospector found evidence of water in craters at the moon's poles.
[TB] {EA}