Some interesting facts about the moon
The moon, only natural satellite of the earth. It is an 81 million billion ton lump of rock and dust. It is more than 3476 kilometres in diameter, orbiting almost 3.84 lakh kilometres above our head. It is the second brightest object in our skies. The temperature on the moon varies from 127 degrees Celsius (during the day) to -173 degrees Celsius (at night). Its gravitation force is 1/6th that of our earth, which means a person weighing 60 kg on earth will weigh 10 kg on the moon. Mountains shores to 1600 feet and millions of creators litter the dust rise surface. No liquid water has ever been found. This is not a hospitable place.
Apart from the earth, the moon is the only heavenly body where humans have walked on its surface. We are far from alone in having the moon, at least 135 other moons are orbiting the planets of our solar system. Saturn has the most with 46 moons. While we have at least 10 mysterious bodies orbiting our planet, 5 are asteroids caught temporarily by earth’s gravitational field, 4 are probably the remnants of Apollo 12 rocket, and the 10th and largest is our moon.
The theories of the creation of the moon
Since long before the birth of humankind, the moon has been the earth’s constant companion. But until relatively recently we have known a little of its true nature or even how it was created. There are several competing theories about the creation of the moon. One suggests that the moon is merely an asteroid or small planet trapped by the earth’s gravity. Another theory ascribes the creation of a giant impact on the earth, ejecting masses of material in the space that created the moon. This is also known as giant-impact theory and has been widely and scientifically accepted theory to date.
Clues of which theory is likely to be correct came when the men first landed on the moon on July 20, 1969. It started unlocking the secrets of creation buried within the lunar rocks. In fact, it was one of the aims of the Apollo program to figure out how our moon came to its existence. Between 1969 to 1972 six mission blasted off to the moon. It was Neil Armstrong who first put the step of mankind on the moon surface on July 20, 1969. Since then, only 12 fortunate humans have walked over the moon surface. These 12 astronauts did more than just rewrite the history, they also returned with samples of lunar rock. These moon rocks are amazingly similar to the earth rocks but they contain far less iron. This small difference of iron concentration in moon rock offers a huge clue about how the moon was created. It shows that the moon was started with a bang.
The violent past that leads to the creation of the moon
Let’s step back 4.5 billion years in the earth’s history. This earth is nowhere near to the earth that we know today. Conditions on the earth are extremely harsh there is no life. This is not at all an inhabitable place. The earth itself is a very young planet also know as pro-earth. The moon does not yet exist. The inner solar system has about twice as many planets as they exist today. Many of them are on a crash course to destruction. Among them, a planet is about half the size of the earth since named Thea, who in Greek mythology is the goddess mother of the moon. Earth and Thea are on a collision course. Inexorably Thea rushes closer and closer to earth.
The approaching planet Thea is a terrifying sight if you happen to witness the collision site. You would have seen a tinny tiny star approaching you and with time its size is getting bigger and bigger, and eventually, just before the impact it would have completely covered the skies. Its diameter is half of the diameter of the earth (roughly about the size of Mars) and is travelling at a speed of 40233 kilometres per hour. As the planet approaches each other, their immense gravitational field rips the surface of each other and then they catastrophically collide. This impact is equivalent to billions of megaton bombs. The impact shears of a continent size sections of the earth crust, blasting surface rocks out into space. These surface rocks contain only a small amount of iron. The atmosphere around the molten planet (earth) is filled with rock vapour. Earth’s gravity pulls back most of the debris, but some are catapult into space although it cannot escape completely the earths gravity. Instead are trapped by the earth’s gravity forming a ring of red hot dust and rock around the planet.
In a process called accretion, the circling dust and rock collide and fuse with other fragments to create larger blocks. As the debris clumps together its combined gravity became strong enough to attract even more debris. This chain reaction does not stop until the billions of fragments of vaporized rock have gathered into one red hot ball of matter. Due to excessive heat, the outer surface of the moon melts to form the ocean of magma.
The evidence for magma ocean comes from the layered structure of the moon’s interior. Low-density materials like aluminium, feldspar are on the surface and heavy density materials ar at the bottom of the crust and mantle of the moon. This distribution of material is only possible in the liquid state and hence it has been concluded that the moon was once an ocean of the magma.
In less than 100 million years, this cools into a solid lump of rock, 1/50th the volume of the earth. It becomes the moon.
The moon is on the move
When the moon forms, it is just 27000 kilometres away. But it does not state as close as that. Its violent birth set it’s spinning away from earth on a journey that will last for 10 billion years.
Absolute proof that the moon is moving away comes in 1969 when an astronaut leaves an 18-inch reflective plate on the moon’s surface. By bouncing lasers from this plate, scientists can pinpoint the moon’s distance from the earth within an inch. Such calculations reveal that moon is moving away from us at a rate of 1.5 inches per year. So why is the moon on move? We will explore this in the upcoming article.