Knowing The Moon In Depth

Dr. S. S. VERMA; Department of Physics, S.L.I.E.T., Longowal; Distt.-Sangrur (Punjab)-148 106

2019-09-13 07:26:38

Credit: ISRO

Credit: ISRO

Moon which is always there in the sky though we generally see it in the night has become a hot topic with the continuous human endeavors including Chandryan-1 and Chandrayan-2 by Indian scientists to reach to moon. Thus, moon is no more confined as a subject to poetry and poems as well as to science books.  From Earth, we always see the same face of the Moon because the Moon is spinning on its axis at the same speed that it is going around Earth (that is, it is in synchronous rotation with Earth). We want to know in detail about this object which is in our solar system and very close to us.  Some very common and rare facts related to moon and its exploration is given here. In the last it is important to mention that the list of facts cannot be final and last in any way as we are in constant touch with our dear moon which used to be an object of worship and praise but now has turned to be an object of scientific discussions.

Moon facts:

  • Earth's only permanent natural satellite
  • its 1/6th gravity as compared to earth
  • second-densest satellite in our solar system
  • always shows Earth the same face
  • surface is actually dark
  • drifting away from the Earth
  • Sun and the Moon are not of the same size
  • was made when a rock smashed into Earth
  • makes the earth move as well as the tides
  • has quakes too
  • There is water on the Moon
  • We see is the sun lighting up different sides of the moon
  • The moon is about 4.5 billion years old
  • The moon rises in the east and sets in the west
  • The moon is about 250,000 miles (384,400 kilometres) from earth
  • The Moon has a diameter of 2,159 miles (3,476 kilometers) and is about one-quarter the size of Earth
  • The Moon weighs about 80 times less than Earth
  • Analysis of the rocks pinpoint the Moon's creation to 4.51 billion years ago, just 60 million years after the Solar System first formed
  • Under the surface, just like the Earth, the moon boasts a crust, mantle and core
  • Deep inside of its interior, the moon may have a solid iron core surrounded by a softer, somewhat molten liquid iron outer core
  • The Moon orbits Earth in the prograde direction and completes one revolution relative to the stars in about 27.32 days (a sidereal month) and one revolution relative to the Sun in about 29.53 days (a synodic month).

  • The average composition of the lunar surface by weight is roughly 43 percent oxygen, 20 percent silicon, 19 percent magnesium, 10 percent iron, 3 percent calcium, 3 percent aluminum, 0.42 percent chromium, 0.18 percent titanium and 0.12 percent manganese.

Moon Missions:

·Dawn of the Space Age (1950s): USA and USSR started the moon exploration in 1950s to have about seven launched missions each with only partial success of the level of first Moon flyby, then first spacecraft to impact the Moon's surface and first pictures of the lunar far side.

·Race to the Moon (1960s): The race was still totally dominated by USA and USSR with 24 and 30 launching missions respectively with   first humans to land on the Moon from USA (Apollo 11).

·Sampling the Moon (1970s): The race was further totally dominated by USA and USSR with 8 and 130 launching missions respectively with first scientist on the Moon from USA and final Apollo mission (Apollo 17).

·Quiet Moon (1980s): No lunar missions were launched in this decade.

·Robots Return (1990s): Japan was the third country to join USA and USSR in moon exploration. Only Japan and USA launched moon orbiter missions this time with success.

·International Moon (2000s): Europe, Japan, China and India (Chandrayan-1, 10/22/2008) became part of international moon exploration activities along with USA and USSR.

·Delving Deeper (2010s): When USA made only three exploration activities, China made six launching missions and Israel also joined the activities.  India made a great attempt in sending Chndrayan-2 to moon orbits with unsuccessful attempt to land a land rover on the moon surface.

Exploration facts:

  • Only three countries have ever soft-landed on the moon— the United States, the U.S.S.R. and now China. India’s Chnadraya-2  on 07.09.2019 went out of control very near to moon i.e., 2.1km only before safe landing on the moon surface.

  • Among seven Apollo moon landing missions, only one did not land men on the moon. The landing module of Apollo 11 is still there on the surface of moon, marked with a plaque that reads: “Here men from the planet Earth first set foot upon the Moon July 1969, A.D. We came in peace for all mankind.”

  • The nine Apollo missions to the Moon occurred between December 1968 and December 1972. Apart from these twenty-four men who visited the Moon, no human being has gone beyond low Earth orbit.

  • Twelve people have walked on the Moon and all of them agree: the Moon smells like gunpowder.

  • As of 2018, there have been 18 astronaut and cosmonaut fatalities during spaceflight. Astronauts have also died while training for space missions, such as the Apollo 1 launch pad fire which killed an entire crew of three. There have also been some non-astronaut fatalities during spaceflight-related activities.

  • On 3 November 1957, the second-ever orbiting spacecraft carried the first animal into orbit, the dog Laika, launched aboard the Soviet Sputnik 2 spacecraft (nicknamed 'Muttnik' in the West). Laika died during the flight, as was intended because the technology to return from orbit had not yet been developed.

  • While three astronauts flew to the Moon twice, of which two landed, none landed on the Moon more than once.

  • The first person to walk on the Moon is Neil Armstrong and the crew of Apollo 17 (on Dec 7, 1972)-Cernan and Harrison Schmitt are known as the last persons to walk on the Moon.

  • Rakesh Sharma (born 13 January 1949) is a former Indian Air Force pilot who flew aboard Soyuz T-11, launched on 2 April 1984, as part of the Interkosmos programme. Sharma is the first and the only Indian citizen to travel in space till date there have been other Indian origin cosmonauts but not citizens.

  • Only 5% of the Moon's surface has been explored by humans.

  • The first woman in space was a Soviet cosmonaut Valentina Tereshkova launched with the Vostok 6 mission on June 16, 1963. The second woman overall to go into space was also a cosmonaut: Svetlana Savitskaya in 1982 on the Soyuz T-7 mission.

  • Roughly 300,000 craters wider than 1 km (0.6 miles) are thought to be on the moon's near side alone. These are named for scholars, scientists, artists and explorers.