Earth's history is hidden in the moon
The moon is a geologically dead body. Since the initial wave of the formation of the planets in our solar system ended - a process that began with their crystallization from the original gas cloud and ended with the significant decrease in the amount of rocks falling from space - it has remained, in fact, unchanged.
It has a very thin atmosphere, there are no oceans on it, no winds and no flowing water, and since it is a small celestial body, which empties its internal heat into space - it does not have, at least in recent times, active volcanoes. The many materials scattered over large areas of the moon are well preserved, as if they were found in a deep freeze.
This snapshot makes the Moon a vital tool for learning the lost story of the first billion years of the Solar System. And first and foremost, it may help solve the mystery about the process of the Earth's formation and the origin of life.
The astronauts of the Apollo spacecraft brought with them from the moon 22 kg of rocks, from all six of their landing sites. For about 30 years, countless experiments and tests were conducted on these samples. The information collected from them was recently supplemented with data collected by the Lunar Prospector spacecraft, which orbits the moon. Among other things, she is the one who confirmed the existence of huge blocks of ice near the poles, a fact that gives hope to the possibility of establishing a human colony on the moon in the future (due to the availability of drinking water as well as liquid oxygen and hydrogen for rocket fuel).
From the data collected so far, it appears that the surface of the moon is covered with a gravel mass of rock fragments and dust, called lunar regolith. The regolith was formed by many meteorite impacts over a long period of time. The rocks on the surface are unusually enriched in chemical elements and isotopes, which were introduced to them by solar radiation. It turns out that the moon has recorded about five billion years of solar history with a level of perfection that is unlikely to be found anywhere else - and this is a figure that may be important for understanding climate change on Earth.
Very early in history the moon was melted to a great depth, of tens of kilometers or more, which created a "magma ocean". Formed about 4.6-4.4 billion years ago, the lunar plateaus contain the remains of low-density rocks that floated to the surface of the magma ocean. Next came a series of huge asteroid impacts, which created large basins that were filled about 3.9-3.2 billion years ago by lava flows. The many meteorite impacts eroded the ancient lunar plateaus and raised mountain ranges between the basins.
The study of the moon rocks brought back by the Apollo astronauts is currently being conducted in full swing in more than 60 laboratories around the world. New technologies create anticipation among researchers that more secrets of the moon will be revealed in the near future.
In addition to the question of the structure and composition of the moon, researchers are also dealing with the question of how it was formed. About a month ago, data collected by "Lunar Prospector" were published and confirm a theory that the lunar mass was torn from the Earth. Scientists claim that the Moon was formed when a Mars-sized body hit Earth in its early days, when both bodies were hot. "The collision occurred after the Earth's iron core was formed, and caused rocky materials, poor in iron, to be ejected from the outer shell into the orbit," said Dr. Alan Binder, a researcher in the field, "this material is, apparently, what was collected and formed the moon. Necessary , however, further data processing to determine, once and for all, whether the 'massive collision' model of the moon's formation is correct."
"Lunar Prospector" will end its life in the coming weeks with a crash landing into the ice field it discovered near the south pole of the moon. NASA will try to measure the concentration of ice by observing through a telescope the scattering of fragments of the spacecraft.
