What is the average distance of the Moon from the Earth?

The Moon, Earth’s only natural satellite, orbits our planet at an average distance of 384,400 kilometers. This value is often rounded to 384,000 km in textbooks for simplicity. However, the actual distance is not constant because the Moon follows an elliptical orbit, meaning sometimes it is closer (perigee) and sometimes farther (apogee).

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  At perigee, the Moon is about 363,300 km away.

  
  


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  At apogee, it is around 405,500 km away.

  
  

This variation is why the Moon appears slightly larger or smaller in the night sky during different phases, giving rise to phenomena such as supermoons (when the full moon occurs near perigee).

The distance between the Earth and the Moon has important scientific and practical implications:

1. 
   

   Tides: The gravitational pull of the Moon is the primary driver of ocean tides on Earth. Precise knowledge of this distance helps in accurate tidal predictions.

   
   


2. 
   

   Eclipses: Solar and lunar eclipses occur based on the alignment of the Earth, Moon, and Sun, which is directly related to this orbital distance.

   
   


3. 
   

   Space Missions: Early space programs, like NASA’s Apollo missions, had to calculate this distance with high precision to ensure successful lunar landings and safe returns.

   
   


4. 
   

   Laser Ranging: Scientists continue to measure the Earth-Moon distance by bouncing laser beams off reflectors left on the Moon’s surface by Apollo astronauts. These experiments confirm that the Moon is slowly drifting 3.8 cm farther away each year due to tidal interactions.

   
   

When comparing with the given options:

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  350,000 km and 380,200 km are close estimates but not exact.

  
  


• 
  

  384,500 km is very near but slightly off.

  
  


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  The most widely accepted and correct figure is 384,400 km (Option A).

  
  

Thus, the Moon’s average distance is 384,400 kilometers, making it a crucial figure in astronomy, navigation, and Earth sciences.