The Earth’s Moon is the most important moon in the solar system in regards to Earth and all of the living things within it. It is also the only Moon that Earth has, whereas other planets, like Mars, have multiple Moons. The Moon is the only other Moon that humans have set foot on, which helped us to understand the formation, internal structure, and history of it. The “moon’s face” is the second brightest thing in the solar system after the Sun, and has a dark surface in actuality. The phases of the moon have been important in the lives and cultures of living things on Earth in language, calendars, art, and mythology. The Moon also affects certain parts of Earth, like ocean tides. It appears almost the same size as the Sun, although the Sun is actually way more enormous than the Moon.
The formation of the Moon has been proposed to come from 30-50 million years after the origin of the Solar System. It starts with the fission of the Moon, which in turn came from the crust of Earth through centrifugal force. This means since Earth spins, gravity captured a pre-formed Moon into the atmosphere of Earth forming the Earth and Moon together in a primordial accretion disk. However this proposed theory does not include depletion of metallic iron, or high angular momentum of the Earth-Moon system. Another theory is that the Earth-Moon formed after a huge impact in which A Mars-sized object and Earth hit each other and blasted materials into orbit around Earth, which formed the Moon. More recent technology has been able to show us that the Moon particles came from some outside impactor and not from Earth. Moons of other planets have different isotopic compositions of oxygen, whereas Moon and Earth are quite similar. However, recent lunar samples have showed that the Moon and Earth have the same composition, which conflicts the impact theory.
Within the Moon, there is a crust, mantle, and core. The inner core has a radius of 240 kilometers, an outer core made of liquid that is 300 kilometers in radius, and a molten boundary layer with a radius of 500 kilometers. This structure came from fractional crystallization of global magma ocean about 4.5 million years ago. This created a mafic mantle from precipitation and sinking of minerals. Then the magma crystallized and the lower density minerals floated to the top and formed a crust. The Moon is the second densest moon in our solar system after Io and the inner core is the smallest radius.
Moon lost most of its internal heat years ago, which left it with never-ending volcanoes or tectonics. Because of this, the craters on the Moon are visible because of things that have hit it. Its size and gravity is too weak for the Moon to hold gas in its own atmosphere for a long amount of time. Without the never-ending volcanoes it would not be able to replenish the gas lost. The Moon reveals many different types of surfaces, including smooth dark regions and bright-cratered regions. The smooth dark regions are called lunar maria and bright-cratered regions are called lunar highlands.
It was believed that the lunar maria was once filled with water by astronomers, hence the name maria, which is derived from the Latin word maria meaning sea. They are now huge solidified basins of old basaltic lava. They have a high iron concentration, but lack in minerals of water. Maria are found mostly on the near side of the Moon and a few scattered areas on the far side of the Moon due to the different heat concentration in the Moon’s crust. The lunar highlands are higher than the maria. They contain lunar magma ocean, but are not formed by means of tectonic events.
Another geological aspect of the Moon is impact cratering, which happens when carters are formed because asteroids and comets collide with the surface of Moon. There are 300,000 craters on the Moon’s near side only that are 1 kilometer in radius. These craters make up the lunar geological...