The space around Earth is a busy place, as teeming with traffic as a roundabout. More than 500 active satellites are bustling about up there right now. Some are transmitting radio, television, and telephone signals; others are gathering information about Earth's atmosphere and weather; still others are helping people navigate down here; and the rest are conducting space research.

Soon the space around the moon will be busy too. China, Japan, India, Russia, and the US either have sent or plan to send satellites there for a bird's-eye view of lunar features and resources.

Why is the moon such a draw? read more