35+ Interesting Facts About the Moon

1. The moon is the only natural satellite of the earth. It was the only known moon before the 17^th Century. Galileo Galilee discovered the four moons of Jupiter in 1610, the first after the moon of the earth.
2. There are more than 200 natural satellites (moons) in the solar system. Earth’s moon is the fifth largest among these moons. It is also bigger than all dwarf planets in the solar system.
3. Currently, the moon is orbiting more than 400,000 km from the earth. However, this distance was only 22,500 km at the beginning of the moon. The distance between the moon and the earth increases to 1.48 inches annually. It has been happening for the past 4.5 billion years due to the influence of tides on earth. (Source)
4. The moon has the largest ratio to earth compared to any other planet and its natural satellite in the solar system. It is nearly 27% the size of the earth.
5. The moon’s magnetic field is 1,000 times less powerful than the magnetic field on earth despite having a similar iron core. After analysis of moon rocks during the 1970s, it was assumed that its magnetic field was stronger between 3.6 and 3.9 billion years ago. However, the latest studies prove that the moon never had a significant magnetic field. (Source)
6. There is a misconception that human footprints, belongings, and flags can remain forever on the moon due to the lack of atmosphere. However, the impact of micrometeorites can erase footprints and hardware in 10 to 100 million years. The flags can lose their color in a few years due to extreme heat and the UV effect on the moon. (Source)
7. The gravity on the surface of the moon is six times less than the earth’s gravity.
8. Moon is the primary driver of tides on earth with its gravitational pull. Very high Spring Tides (combining the sun’s and moon’s gravitational force) happen twice every lunar month when the moon, sun, and earth come in a line. The moderate tides that appear after a week of spring tides are known as Neap Tides.
9. We can only see one side of the moon from the earth, known as the near side. The far side of the moon was initially sighted in 1959 when a Soviet spacecraft passed close to it. 

   

   Humans initially sighted the far side of the moon in 1959

   
   
10. The moon formed billions of years ago after the collision of earth and a Mars-sized celestial object. According to the latest research, the formation of the moon took only a few hours after this collision. (Source)
11. The light and dark areas of the moon are known as highlands and maria, respectively. Maria got filled with liquid magma between 4.2 and 1.2 billion years ago. The composition and age of rocks in both these locations are different.  
12. The moon reflects 12% of the receiving light and absorbs the remaining. Mercury is the only major body in the solar system with less reflectivity (11%) than the moon. It looks bright due to its proximity to the earth. (Source)
13. The full moon is the largest and brightest object in the night sky. It is also the second-brightest object in the sky after the sun.
14. The moon has a core, mantle, and crust. The inner core is made chiefly from iron and surrounded by a liquid iron shell. It is smaller than the cores of other terrestrial bodies.
15. The moon has a thin and weak atmosphere, not capable of shielding it from meteorites and sun radiation. Its density is one-trillionth the density of the earth’s atmosphere. This atmosphere contains sodium, potassium, and other gases not present on Venus, Earth, or Mars.
16. The surface of the moon contains fine and sharp dust that can destroy hard materials and penetrate deep into the lungs. This lunar dust can destroy lung and brain cells. However, the bricks made from this dust can protect astronauts. (Source)
17. The radiation level on the moon is 200 times more than on the earth’s surface. This radiation level is 2.6 times higher than faced by astronauts on ISS (International Space Station). (Source)
18. Luna 9 by the Soviet Union was the first spacecraft that achieved a soft landing on the moon on February 3, 1966. The American-launched Surveyor 1 achieved a similar result four months later.
19. The surface of the moon receives extreme temperatures. The daytime and nighttime temperatures at the lunar equator can reach 120 C and -130 C, respectively. The lowest temperature ever recorded in the solar system was -250 C on the floor of the Hermit Crater on the moon. (Source)
20. The entire moon’s surface has coverage of powdery dust and rocky debris, known as lunar regolith. It happened due to the continuous bombardment of comets and asteroids on the moon for billions of years. 
21. The South Pole-Aitkan basin is the largest and deepest crater in the Solar System. It is 12,000 m (39,000 ft.) below its rim and has a diameter of 2,250 km (1,400 miles). (Source)
22. The highest point on the moon is 10,786 meters above the mean radius. This highest point was formed more than 4 billion years ago, while the highest point on earth (Mount Everest) appeared 60 million years ago. (Source)
23. The moon has been continuously shrinking for the past 700 million years due to the cooling of its interior. This shrinking has caused wrinkling of its surface and moonquakes. (Source)
24. The near and far sides of the moon receive nearly the same number of impacts. However, there are more impact craters on the far side of the moon because the eruption of volcanoes on the near side has filled and covered the ancient large impact craters. (Source)
25. Meteors have hit the moon and earth numerous times in the past 4.5 billion years. However, the moon has thousands of craters compared to around 180 on the earth. Our planet can erase the impact of meteors with erosion, tectonics, and volcanic flows. The moon has no atmosphere (that causes erosion) and tectonics. There is also no evidence of volcanic activity on the moon for the past 3 billion years. (Source)
26. Like earthquakes, several types of moonquakes also occur. These moonquakes originate from the earth’s gravity, meteoroid impacts, or expansion and contraction of rock.
27. Along with the earth, the moon is the only place humans have set foot. So far, only 12 humans have walked on the moon, all US citizens. These moon landers belong to various missions from Apollo 11 to Apollo 17. Twelve others only traveled from earth to the moon. (Source) 

    

    Only 12 humans have so far landed on the moon

    
    
28. According to research, the moon plays a vital role in generating the earth’s magnetic field. The moon performs this function through the energy produced during its tidal effects. The magnetic field protects the earth from the sun’s radiation. (Source)
29. The moon affects earth through its light, cycle, and impact on tides. Several organisms rely heavily on the moon to fulfill vital tasks. These include dung beetles, petrels, sand hoppers, limpet, the Great Barrier Reef, and Mormon tea. (Source)
30. The supermoon looks brighter and larger than a general full moon. It occurs when the full moon orbits around the earth at the closest point (perigee).
31. A blue moon appears when there is a second full moon in a solar month. It happens once every 33 months.
32. Solar eclipses only occur during the new moon phase. On the contrary, lunar eclipses happen at the full moon. The moon appears red during a total lunar eclipse.
33. Russia (the USSR), the USA, Japan, ESA (European Space Agency), China, and India have sent missions to the moon. In 2019, China became the first country to achieve a soft landing on the lunar far side.
34. Researchers have grown plants on the soil brought from the moon for the first time in 2022. However, their growth was slow and stunted. These plants performed worst under solar wind and cosmic radiation, similar to the conditions present on the moon. (Source)
35. In 1958, the US Air Force planned to detonate a hydrogen bomb on the moon to show strength during the space race between the USA and the Soviet Union. However, this plan never materialized for unknown reasons. (Source)
36. Most rocky planets and moons have a spherical shape due to magma. However, the moon is different from them due to its lemon-like figure. It is the result of the earth’s gravity, which produced a bulge on each side of the moon. (Source)
37. There have been different views about the presence or absence of water on the moon since the 17^th Century. However, water was confirmed on the permanently shadowed regions of the moon in 2018 through the data received from NASA’s instrument M3 (Moon Mineralogy Mapper), carried by the Indian Chandrayaan-1 spacecraft. NASA also confirmed the presence of water in the moon’s sunlit areas in 2020.