86 FAQs about the Moon (The Astronomy Cafe)


Basic Facts: NASA/NSSDC Fact Sheet, Links

Missions: Prospector,Ranger,Orbiter,Surveyor,Apollo,Clementine

Calculators: Apogee and Perigee

Pictures: NASA Archive

 Back to the Astronomy Cafe - 365 of the most popular questions since 1996. Over 1 million page requests!


  1. [Updated]How hot is the Moon?
  2. [Updated]Have any new craters been seen in the 100 years of lunar photographs taken from Earth?
  3. [Updated]Has ice really been detected on the Moon?
  4. [Updated]Has anyone used a powerful telescope to look at the old Apollo landing sites?
  5. [Updated]Why is the lunar month exactly equal to the human female menstrual cycle?
  6. [Updated]What is the physiological process behind the Moon Illusion?
  7. [Updated]What is it about the lunar surface that makes it so bright from the Earth?
  8. [Updated]How is it possible to see the Moon in the daytime?
  9. [Updated]How rapidly does dust accumulate on the surface of the Moon?
  10. [Updated]How long does a lunar month last?
  11. [Updated]Is the Moon moving away from the Earth?
  12. Why does the Moon rise 50 minutes later each day?
  13. Does the Moon have an atmosphere?
  14. [Updated]Why do some craters have rays and others not?

  15. Is the rotation speed of the Earth slowing down?
  16. Have gold, silver or diamonds been found on the Moon?
  17. Is the brightness of the Half Moon really 1/9 the Full Moon?
  18. Can you buy land on the Moon?
  19. If I stood on the Moon, would I see the Earth?
  20. Is there such a thing as Moon germs?
  21. Does our Moon have a technical name?
  22. When we see the Moon in the daytime in North America, do chinese observers see it at night time?
  23. How high can you jump on the Moon?
  24. At what depth do moonquakes occur?
  25. How many pounds of Moon rocks were brought back to earth?
  26. Can sound travel through the thin atmosphere of the Moon?
  27. Are there any active volcanoes on the Moon?
  28. Has anyone ever seen a crater form on the Moon?
  29. Which way does the Moon go around the Earth?
  30. Is there a place on the Earth where you will never see the Moon?
  31. Where is the barycenter of the Earth-Moon system located?
  32. What is the exact orbital period of the Moon?
  33. What is the distance to the Moon?
  34. How often are planets occulted by the Moon?
  35. There was a large ring around the Moon one night. What was it?
  36. What is the history behind the Man in the Moon?
  37. What is the term for the point between Earth and Moon where the gravitational forces are equal?
  38. What is the Moon's speed per day relative to the stars?
  39. Has the Moon ever rotated faster than it does now?
  40. Does the Earth go through a complete cycle of phases from the Moon?
  41. Are the rocks on the moon like the ones on earth?
  42. Does the Moon have magnetic poles too?
  43. By how much does the Moon's apparent diameter in the sky change?


  1. [Updated]How far away from the Earth was the Moon first formed?
  2. [Updated]What would happen if the Moon suddenly left orbit around the Earth?

  3. Is there an archive of lunar perigee and apogee distances for the future?
  4. How will gamma rays be used to detect water ice on the Moon?
  5. If the Earth's rotation were reversed, what would happen to the Moon?
  6. What effect did the Moon have on the Earth during the first few billion years?
  7. Is there an approximate way to calculate the distance to the Moon for any given day?
  8. How was the Moon formed?
  9. Why does the Moon seem bigger on the horizon than high up in the sky?
  10. The Earth- Moon system is almost a double planet. What would have happened if Earth had no Moon?
  11. Creationists say that the lunar crust is thin which means the moon was formed recently. Is this true scientifically?
  12. Who owns the Moon for commercialization purposes?


  1. What would happen to the Moon if the Earth changed its mass by 1/2 or 1/4?
  2. Can other moons in the solar system get synched with their planets rotation?
  3. For part of its orbit, the Moon is close to the Sun. Why doesn't the Moon escape the Earth then?
  4. Could you explain what causes the Moon's synchronous rotation?

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