Why in News?

International Moon Day was recently observed to commemorate the anniversary of the first human landing on the Moon by Apollo 11 on July 20, 1969 and to raise awareness about sustainable lunar exploration and international cooperation in space science.

About International Moon Day

• Observed on: July 20 every year. 
• Purpose: To mark the first human Moon landing by Apollo 11 in 1969. 
• Key Moment: On this day, Neil Armstrong and Buzz Aldrin became the first humans to walk on the Moon. 
• UN Recognition 
  • Declared by UN General Assembly Resolution 76/76 in 2021. 
  • Based on a recommendation from the Committee on the Peaceful Uses of Outer Space (COPUOS). 
  • The first global celebration was held on July 20, 2022. 

Moon

Name Origin 

• The Moon was simply called "the Moon" because people didn’t know other moons existed until 1610, when Galileo Galilei discovered Jupiter’s moons. 
• In Latin, it was called Luna, giving rise to terms like lunar. 

Size and Distance 

• Radius: 1,080 miles (1,740 km) about one-third the width of Earth. 
• If Earth were a nickel, the Moon would be the size of a coffee bean. 
• Distance from Earth: 238,855 miles (384,400 km) enough space to fit 30 Earths in between. 

Rotation and Orbit 

• The Moon takes 27 Earth days to complete one rotation and one orbit around Earth — known as synchronous rotation. 
• Due to Earth's motion, the Moon appears to orbit Earth every 29 days from our perspective. 
• The same side of the Moon always faces Earth. 

Rings and Moons 

• The Moon has no rings. 
• It also has no moons of its own. 

Structure 

• Composed of core, mantle, and crust. 

Atmosphere 

• Has a very thin and weak atmosphere, offering no protection from solar radiation or meteoroid impacts. 

Magnetic Field 

• Once had a magnetic field generated by an internal dynamo. 
• Today, its magnetic field is extremely weak, thousands of times weaker than Earth's.