Our moon is believed to have formed roughly 4.5 billion years ago, not long after our Earth. The most widely accepted theory is the Giant Impact Hypothesis, suggesting it formed from the debris of a collision between the young Earth and a Mars-sized body known as Theia.
The Moon is slowly drifting away from Earth at a rate of about 1.5 inches (3.8 centimeters) per year. This is due to tidal forces between Earth and the Moon. Enjoy it while it lasts!
The Moon was first visited by humans during the Apollo 11 mission in 1969. Neil Armstrong and Buzz Aldrin became the first and second humans to walk on its dusty surface. Learn more about the Apollo missions.