The only natural satellite of the Earth and the 5th largest among all the satellites in the solar system, the Moon is a great celestial body in our solar system which the universe has bestowed upon us. With an appearance that is calm and ever-fascinating, Moon has been a subject matter of interest for many since the ancient times and has a strong relevance in our mythologies, cultures, arts and calendars. The day Galileo observed Moon closely through his telescope; he would not have imagined that one day a human would set foot on the grounds of this glowing element in the sky above our heads. But then, he may not have imagined lots of things science is discovering about the Moon today. Here is an entire section to feed your curiosity for the Moon and related facts. Take a glance!
Distance From Sun: 147 million kilometres
Average Distance From Earth: 384,400 km
Mean Radius: 1737.5 km
Mean Circumference: 10,917.0 km
Volume: 21,971,669,064 km3
Mass: 7.34 x 1022 kg
Density: 3.344 g/cm3
Surface Area: 37,936,694.79 km2
Surface Gravity: 1.624 m/s2
Length of Day: 27.322 Earth days
Length of Year (Orbital Period): 0.074803559 Earth years
Average Orbit Velocity: 3,680.5 km/h
Orbit Inclination: 5.16 degrees
Orbit Circumference: 2,413,402.16 km
Average Temperature: -233°C/123 °C (Min/Max)
Interesting And Fun Facts About Moon
- It is believed that Moon was formed when a Mars-sized body collided with the Earth about 4.5 billion years ago. The debris of this collision from both bodies got accumulated to form the Moon, the natural satellite of Earth.
- Moon doesn’t have an atmosphere so a number of asteroids, meteoroids and comets have been crashing into it since its formation. The rain of these celestial bodies has made the surface a pile of heavy boulders to powder over some billion years.
- The surface of Moon is two-layered. The Upper layer known as lunar regolith, is a rubble pile of charcoal-gray, powdered dust and rocky wreckages while the Lower Layer known as the megaregolith, is the region of fractured bedrock.
- The Nectaris and Imbrium basins and the craters Erathosthenes and Copernicus are the impact structures used to classify objects on the Moon as per the time of their existence.
- Because of being a differentiated body, the Moon has geochemically different core, mantle and crust. While its core, with a radius of 240 km, is made up of solid iron whereas its crust, 50 km thick on average is made up of pyroxene, ilmenite, magnetite, and olivine.
- Around 30,000 craters are estimated to be located on the near side of the Moon alone. All these craters are wider than 1 km.
- It is estimated that around 14,000 km2 of Moon’s surface lies in permanent darkness. This region is also referred to as the ‘Dark Side of the Moon’.
- Water in liquid form is not known to exist on the surface of the Moon. However, Chandrayaan-1 spacecraft, in 2008, has confirmed the presence of surface water ice.
- Because of its proximity to the Earth, Moon appears to be the brightest object around, standing second to the Sun. In fact, Moon reflects light of the Sun and has none of its own (for it doesn’t generate energy on its own). In actuality, Moon has a dark coal-like surface.
- From the Earth, the Sun and the Moon look exactly of the same size. However, the sun is about 400 times larger than the Moon but sun is also 400 times farther from the Earth!
- Moon is about a quarter of diameter of Earth. And taking into consideration the size of the related planet i.e. the Earth, the size of the Moon makes it the largest natural satellite of any planet in the solar system,.
- Moon is the second densest natural satellite of the solar system, lagging only behind Io, the innermost Galilean moon of the planet Jupiter.
- Galileo Galilei was the first person to make a scientific observation of the Moon, using a telescope.
- Moon is called the ‘Moon’ because we did not know about other moons in the solar system until Galileo Galilei discovered four moons orbiting the Jupiter in 1610. Thereafter, all the moons of other planets then were given names, so as not to confuse each with other moons.
- The first visitors to the Moon are the USSR’s spacecrafts Luna 1 and Luna 2, who first visited it in 1959. Later, a number of U.S. and Soviet robotic spacecrafts were also sent to the Moon.
- Moon is the only celestial body in the entire solar system visited by humans. It was first stepped foot on by Neil Armstrong and Edwin ‘Buzz’ Aldrin on 21st July 1969. Over the next three years, ending in 1972, a total of 12 people set foot on the surface of the moon, the last one being Eugene Cernan.
- The gravity of the Moon is just 17 percent than that of the Earth, so, if you weigh 60 kg on the Earth, you will weigh just 10 kg on the Moon!
- This same gravitational force of the Moon is a cause of the ocean tides and the minute lengthening of day on the Earth.
- During a total solar eclipse, the Moon fully covers the sun, as seen from Earth.
- Moon, by moderating Earth’s wobble on its axis, has been stabilising the climate of the planet Earth from billions of years.
- Since the time taken in rotation on their respective axis is same for the Earth and the Moon, we always tend to see only one side of the Moon. This is called synchronous rotation of the Earth and the Moon.
- The dark features of the Moon are known as ‘Maria’ (referring to ‘sea’ in Latin), while the light features are called as the ‘Highlands’. These dark features are the impact basins which are believed to have been filled with lava about 4 to 2.5 billion years ago.
- The lunar crust of the Moon has influences of magnetic field whose source is yet unknown, as there is no internally generated magnetic field on it.
- Moon is drifting away from the Earth at a rate of 4 centimetres a year. However, it is expected that in the next 50 billion years it will stop drifting and both, the Earth and the Moon will be tidally locked to each other.
- NASA is planning to set up a permanent research station at Moon!
- The Outer Space Treaty which is the basis of the international space law allows all nations to explore Moon for peaceful purposes.