The astrobiologists hypothesized that remnants of Earth's distant past could be found preserved on the moon
Pictured: such planetesimals filled the solar system when the Earth was young
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Rocks from Earth on the Moon
20/10/2002
Everyone is afraid of asteroids. Although the chance of the Earth being hit by a large asteroid is quite small, the consequences of such an impact would be devastating: tsunami waves, climate change and even mass extinctions. Fortunately, this does not happen often.
4 billion years ago this happened all the time. Our planet was still young and the inner solar system was filled with prototype planets the size of large asteroids. These were remnants of the building blocks of the planets. These prototypes are called planetesimals. Some of them big and some of them small hit the earth every day. This period known as the Great Bombardment period lasted from 4.5 billion years ago to 3.8 billion years ago - a period that was not particularly friendly to life on Earth.
The structure of the early Earth is the subject of a conference that convened in October 2002 with the participation of experts and students from around the world who discussed aspects of astrobiology. The NATO Institute for Advanced Studies sponsored the event together with NASA's Marshall Space Flight Center.
The participants in the yeshiva noticed something interesting related to the period of the great shelling. From 3.8 billion years ago we have fossil evidence of life on Earth. The existence of a thriving world of bacterial life so soon after these catalytic bombardments means that life originated on Earth during that difficult period.
How can this exist? Did the comets or asteroids bring life to Earth?
Maybe life evolved from the organic building blocks that arrived in comets? no one knows Astrobiologists like to study the chemical composition of fossils from this period, but due to wind, rain, earthquakes and continental movement, these fossils have been completely eroded.
Or maybe not.
Scientists who participated in the conference hypothesized that such fossils exist, but they cannot be found on Earth but on the Moon.
In the photo: The conditions on the moon led to the preservation of ancient craters on Earth, they have long since disappeared.
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When a large object hits the Earth, debris from the impact may reach orbital velocity. 4 billion years ago the earth was probably surrounded by such remnants that were blown this way. The Moon itself is a lump larger than Earth that was ejected after a Mars-sized planetary impact hit it 4.5 billion years ago. During the Big Bang, the Moon was much closer to Earth than it is today, maybe 3 times closer. This placed the moon in the ideal place to receive some of these remnants that were blown off the earth.
Since there is no tectonic or atmospheric activity on the moon, these remnants may be there.
While some were destroyed by later asteroid or comet impacts on the moon, some may have survived on the lunar soil. A recent University of Washington study conducted by John Armstrong and Lid Wall, along with Julilemo Gonzalez at Iowa State University, the researchers hypothesized that 20 kilograms of material from Earth could be spread over an area of 100 square kilometers on the surface of the moon.
David McKee, an astrobiologist at NASA's Johnson Space Center, said that "the Moon is in a unique position to collect emissions from Earth. If we look in the right places we can find a pool of such materials for study."
In the photo: Apollo 16 astronaut Charles Duke collects rock samples from Plumb crater on the moon
Of the approximately 400 kilograms of lunar rocks that are already on Earth thanks to Apollo, the question has been raised as to whether such earthly materials can be found in these samples. According to McKee - the answer is negative. "There was no report on earthly substances, for example organic substances, found in these samples. This is a new field of science and has not been talked about in the thirty years since the Apollo mission.
Where then could the astronauts look for such stones on the moon? There are several options. One place according to John Armstrong would be on the eastern rim of the Moon, as seen from Earth (of course it is not a rim on the spherical body of the Moon, but only in its two-dimensional aspect as seen from Earth). The moon's rotation around its axis is synchronized with its orbit around the Earth, Armstrong explains. This means that the same side of the earth - the eastern rim - is always the first place to circle the earth. This leading edge may attract more flying chips than other areas.
This is of course true of the remains harvested from their orbit around the Earth. Those that fell directly from the Earth onto the Moon can be found anywhere on the side facing the Earth. Third case - of materials that spent thousands of years or even millions of years in orbit around the Sun, but returned and met with the Earth-Moon system and then they were pumped to the Moon in a random pattern.
Pictured: A meteor that fell from the moon to the earth and was discovered in Australia. In the opposite direction to the topic of the article.
How would it be possible to differentiate between terrestrial rock and ancient lunar rock? After all the moon itself is an old remnant of the earth? According to Armstrong, the question is still under debate. "There are some possible chemical differences," he says. One of them will be water inventions. Earth's oceans formed after the moon split apart from us. Thus while the moon rocks themselves are dry, some rocks from Earth will contain hydric minerals - those that contain water within their molecular structure.
Other differences could be the presence of hydrocarbons or carbonates.
It is possible that a series of flights to the moon will be needed to locate such rocks: "We can develop automatic robotic techniques that will enable the scanning of thousands or millions of small rocks, while searching for earthly materials on the surface of the moon. Appreciate McKee. "It would be like looking for a needle in a haystack - a task that would be complicated to do manually, but quite easy to do by robots. We need to know which properties are the distinct differences of terrestrial materials from those of the moon and program the devices to moon them.
They say that traveling always makes you feel like you miss home. In this case, a trip to the moon may be the only way to understand Earth's chaotic early period.
The key is with the neighbor
By Matthew Gang, Guardian (The Science website was part of the IOL portal of the Haaretz group)
It is possible that the evidence for the formation of life on Earth is actually on the Moon
For every 100 square kilometers on the surface of the moon there may be 20 tons of rocks from Earth
Photo: NASA
Everything that has ever walked, crawled or stayed put on Earth, and in whose body metabolism took place, is a descendant of a common ancestor: a watery sac of complex biological reactions. What was this organism and how did it manage to turn from inanimate, from organic chemistry, into a developing and multiplying bacterium - this is one of the greatest scientific mysteries.
The problem, of course, is that this all happened so long ago. Even the oldest rocks on Earth, 3.8 billion years old, contain faint chemical evidence of microbial influence.
The latest research in this field raises the possibility that the place where you should look for fossils of the earliest living creatures on Earth is actually the moon.
Rocks that are more than 3.8 billion years old have not survived on Earth because at that time the surface was bombarded by giant icy, comet-like bodies. The collisions created huge craters, melted large parts of the Earth's surface and scattered molten debris across the planet. No sign of this era, known as the "Age of Great Collisions", remains on Earth. But the collisions left a mark on the moon, in the form of massive craters visible from Earth with the naked eye.
The existence of bacteria at the end of the Great Collision Period suggests that the first living things came into the world during this early and nightmarish chapter in Earth's history. This is not a case. According to the explanation, the frozen bodies that hit the earth brought with them the water from which the oceans were formed, and the carbon, sulfur and phosphorus that were needed for the formation of living beings. Comets also include complex organic molecules, such as amino acids and sugars, which are the building blocks of proteins and DNA, and may have provided the necessary material, in the necessary form, to give life its first push. It is possible that even the collisions themselves, despite the destruction they sowed, produced the energy required to trigger the chemical reactions that, by chance, caused life to appear.
Despite extensive searches in the oldest areas of the Earth's surface, no rocks originating from the period of the great collisions have been found. And in the absence of these rocks, the origins of life on Earth may never be known. However, a study by two students at the University of Washington now raises the possibility that the searches were not conducted in the right place.
The presence of meteorites from Mars and the Moon on Earth's surface suggests that rocks blown off the surface of one planet, following a major collision, could eventually land on another planet. John Armstrong and Lloyd Wells, along with Guillermo Gonzalez of Iowa State University, estimated that there may be 20 tons of Earth rocks per 100 square kilometers of the Moon's surface, most of which are the result of the Great Collision Period. There may be enough such meteorites on the Moon, originating from Earth, that could provide fossil evidence for the beginning of life on Earth.
At the time of the big collisions, the Moon was three times closer to Earth than it is today, and was, according to David McKay, an astrobiologist at NASA's Johnson Space Center, "in a unique position to absorb material ejected from Earth." If we look in the right places, we may find a pool of materials for research."
Several places on the moon may be preferred destinations for search: first and foremost the side that has always faced Earth. One can also speculate that ancient rocks from Earth survived more easily on the Moon because in the absence of water, wind and rain, and without the movement of tectonic plates, the surface of the Moon has changed very little over billions of years.
Ancient rocks from Earth have not yet been found among the 380 kilograms of moon rocks returned by the Apollo space flights. But many of these rocks date back to the time of the great collisions, and hence it is very possible that there are meteorites on the moon that originated on Earth. According to McKay, robotic research vehicles, which can scan millions of small stones, will one day be able to scan the surface of the moon in search of traces of water and carbohydrates that will testify to the existence of meteorites from Earth, on their chemical fossils.
