As we move away from the earth here comes our first neighbor, the Moon. Our constant companion from 4.51 billion years. Planetary Scientist predicted that the moon was formed when our Solar System was young and full of action. There were collisions going on all over the Solar system. An astronomical body called Theia, about the size of mars, was on collision course with young earth. They collided and leftover debris orbited the earth. Over time debris accumulated together to form only natural satellite of earth.
Moon is tidally locked to Earth; which means we can see only one face of it while other face remaining unseen to most of us. For most of human history so-called of the dark side of moon remained hidden until 1959, when Soviet Luna 3 space probe photographed it, revealing the far side of the moon.
Tidal lock of earth and moon
Far side Dark side of the Moon
The far side of the moon is rugged with a large number of craters, showing a large number of asteroid collisions. It acts as a shield to Earth from possible asteroid collisions.
First Step on the moon
As moon doesn’t have any atmosphere, therefore, footprints left by Neil Armstrong are still there and will be there as long as the moon itself. Because there is no erosion due to the absence of wind and water.
So it brings us to question for how long moon will be there.
Well, obviously we are not fooling enough to destroy the moon on purpose, or are we?
In 1958 United State Air force developed as top-secret plan known as Project A119. The project was aimed to detonate a nuclear bomb on the moon to answer mysteries in planetary astronomy. But it was canceled mainly out of fear of negative public reaction.
The explosion would have been visible faintly from Earth but it couldn’t destroy moon or knock it out of orbit.
But Moon is going away from us about 3.78cm per year. It is mainly due to the action of the Earth’s tides. The Moon is kept in orbit by the gravitational force that the Earth exerts on it, but the Moon also exerts a gravitational force on our planet and this causes the movement of the Earth’s oceans to form a tidal bulge.
Slowing of rotation of Earth by tidal bulges
Due to the rotation of the Earth, this tidal bulge actually sits slightly ahead of the Moon. Some of the energy of the spinning Earth gets transferred to the tidal bulge via friction.
This drives the bulge forward, keeping it ahead of the Moon. The tidal bulge feeds a small amount of energy into the Moon, pushing it into a higher orbit like the faster, outside lanes of a test track.
But the energy gained as the Moon is pushed higher is balanced by a reduction in the energy of its motion – so an acceleration provided by the Earth’s tides is actually slowing the Moon down.
3.78cm may not seem much, but over a long period of time, it could affect life on Earth, making planet slow. When the earth was young about 4.5billion years ago, days were five hours long but due to the slowing effect of the moon now we have 24 hours day. And it will be much longer in the future.
So if you are having a long bad day, the Moon is to blame.
Beautiful Solar Eclipses
Moon is the brightest and largest feature in the night sky. Moon is at distance of 384,400km (Dmoon) and has a diameter of 3,474 km (dmoon); while Sun is at distance of 149.6×106km (DSun) having the diameter of 1.4×106km (dSun).
So by slight math DSun/dSun = (149.6×106/1.4×106)= 106.85
And Dmoon/dmoon = (384,400/3,474) = 110.65
Cause of Solar Eclipses
This ratio is nearly equal and is the reason we have complete solar eclipses. The sun’s 1.4×106km diameter is fully 400 times greater than that of our moon, which measures just about 3,474 km. But the moon also happens to be about 400 times closer to Earth than the sun (the ratio varies as both orbits are elliptical), and as a result, when the orbital planes intersect and the distances align favorably, the new moon can appear to completely blot out the disk of the sun.
Future on Moon
Moon is completely different from anything on Earth. It weighs around 7.35×1022kg, which is about 81 times less than Earth’s mass (5.97×1024kg). Thus gravity on the surface of the moon is much weaker than on Earth. So would weigh one-sixth of your weight on Earth.
can serve as a base for further space exploration. Colonization of the moon has been in the discussion for a long period of time. Proposed projects like Project Horizon, Lunex project were focused on creating a military base on the moon.
Proposed Civilized Moon
In 2017 Moon village association was created to promote international discussion to foster the implementation of permanent human settlement near the lunar South Pole.
Russia, Japan, and China have future plans to land humans on the Moon. Aerospace companies like SpaceX have plans to colonize moon using its BFR launch system.
Thanks to the Chandrayaan-1, mission by ISRO (Indian Space Research Organization) we have detected water on the Moon.
Creating a base on the moon is beneficial in many ways. The energy required to send objects from the Moon to space is much less than from Earth to space. It can serve as a site for launching rockets with locally manufactured fuel to distant planets as Mars. Asteroid mining may prove useful in lowering various costs.
It can be useful in studying in effect of lower gravity on the human body, developing technologies for further space exploration. There is a cool video showing what would be like to live on the moon by my favorite youtuber Vsauce3
But there are some hurdles in the way. The colony has to be designed to withstand large temperature extremes. The temperatures on the surface on the moon varies from -178.20C to 1270C. Also, the moon is highly deprived in volatile elements as nitrogen and hydrogen. If no feasible means found to extract polar ice caps, they have to be imported from other sources. The absence of atmosphere makes moon vulnerable to cosmic rays whose exposure is dangerous for humans. Further development in technologies and investment of non-government institutes in this sector may make lunar colony possible in near future.
“The moon is a friend for the lonesome to talk to.” -Carl Sandburg
There is amazing video by NASA giving the virtual tour of the Moon :
(Source of above information is NASA, wikipedia, and space.com)
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