What is the Distance to the Moon?

TL;DR

The Moon is 384,000 km from Earth, varying about 44,000 km due to its elliptical orbit and can appear different sizes.

Transcript

I'm Fraser Cain, the publisher of Universe Today. The Moon is such a familiar object in the sky, but did you ever wonder how far away it is? The answer is, on average, 384,000 kilometers from Earth. It's hard to put that into context, so let's do a demonstration. Here's the Earth... and here's the Moon to scale. Now how far away would I have to sta... Read More

Key Insights

• ⏰ The Moon is 384,000 km on average from Earth, varying up to 44,000 km due to its elliptical orbit.
• 📑 Perigee (363,000 km) and apogee (406,000 km) mark the Moon's closest and farthest points from Earth.
• 🧡 Laser ranging experiments help astronomers measure the Moon's distance with precision.
• 😚 Supermoons occur when the Moon is closer to Earth, appearing larger in the sky.
• 🕧 The Moon's distance affects its illumination, varying by more than thirty percent from Full Moon to Full Moon.
• 🥺 The Moon orbits Earth on an elliptical path, leading to distance fluctuations.
• ☠️ The Moon is slowly moving away from Earth at a rate of 3.8 cm/year.

Questions & Answers

Q: How do the Moon's distance variations affect its appearance?

The Moon appears larger during perigee (Supermoon) at 363,000 km and smaller during apogee at 406,000 km due to its elliptical orbit.

Q: How do astronomers measure the Moon's distance accurately?

Astronomers use the Lunar Laser Ranging experiment with retroreflecting mirrors on the Moon's surface to calculate precise distances with millimeter accuracy.

Q: How does the Moon's distance change over time?

The Moon is drifting away from Earth at 3.8 cm/year, resulting in a gradual decrease in apparent size over billions of years.

Q: What is the significance of the Moon's distance variations?

Understanding the Moon's distance variations helps astronomers study its orbit dynamics, lunar phases, and Earth-Moon interactions.

Summary & Key Takeaways

• The Moon is an average of 384,000 km from Earth, with its closest point (perigee) at 363,000 km and furthest point (apogee) at 406,000 km.

• The Moon's distance affects its size, with a Full Moon appearing larger during perigee (Supermoon) due to closer proximity.

• Astronomers use laser ranging to measure the Moon's distance, which is slowly drifting away from Earth at 3.8 cm/year.