According to the Giant Impact hypothesis, the Earth-Moon system was created about 4.5 billion years ago when Mars-sized object collided with Earth. This influence led to the release of enormous quantities of material that eventually merged into Earth and the Moon. Over time, the Moon gradually migrated far away from Earth and took over its current orbit.
Since then, there has been regular exchanges between Earth and Moon due to their impact on their surfaces. According to a recent study, the impact that occurred during Hadean Eon (about 4 billion years ago) might have been responsible for sending the oldest rock pattern to the moon where it caught it Apollo 14 astronauts.
Study, which recently appeared in the journal Earth and planetary science letterswas led by Jeremy Bellucci of the Swedish Museum of Natural History, and members of the Lunar and Planetary Institute (LPI), Multidisciplinary Universities and the Center for Science and Research of the Moon (CLSE), which is part of NASA's Virtual Research Institute's Virtual Research Research.
This discovery was made possible thanks to the new technique developed by the research team to locate the impact head fragments in the Lunar Regiment. The development of this technique was inspired by Dr. David A. Kringa – the chief investigator at the CLSE and USRA scientists at LPI – to challenge them to find part of Earth on the Moon.
The resulting investigation led them to find a 2 g (0.07 oz) fragment of rock composed of quartz, feldspar and zirconium. Rocks of this type are usually found on Earth but are very strange on the Moon. Moreover, chemical analysis showed that the rocks crystallized in an oxidized system and at temperatures that were consistent with Earth during Hadean; instead of the moon, who then experienced more temperatures.
As Dr Kring cited in a recent press release:
"It's an outstanding discovery that helps to paint a better image of the Earth's wounds and the bombing that has modified our planet at dawn of life."
Based on their analysis, the team concluded that the rock was created in Hadean Eon and launched from Earth when a large asteroid or comet affected the surface. This impact would have escaped the material into a space where it collided with the Moon's surface, which was three times closer to the Earth at that time. Finally, this rocky material mixed with the Lunar Regiment creates a unique pattern.
The team could also learn a lot about the rock pattern history from their analysis. First, they concluded that the rock crystallized at a depth of about 20 km below Earth's surface between 4.0. and 4.1 billion years ago, and then excavated by one or more major events that sent it to the cis-lunar space.
This is in line with a previous team survey that has shown that the effects of that time – that is, the Late Bombing (which occurred about 4.1 to 3.8 billion years ago) – produced craters of a thousand kilometers, more than enough to eject material from a depth of 20 km into space.
Further, they found that several other influences affected him after reaching the lunar surface. One of them caused the sample to partially dissolve before about 3.9 billion years and could bury it under the surface. After this period, the moon was subjected to shots that were smaller and shorter, and gave it the surface that was being processed today.
The final impact event that influenced this pattern occurred about 26 million years ago during the Palaeogenesis on Earth. This impact produced a crater crater of 340 m (1082 ft) in diameter and excavated a rock pattern back to the Moon surface. This crater was a landing place Apollo 14 In 1971, when astronauts from the mission received rocks samples to bring them back to Earth for study (including Earth's Rock).
The research team confirms that it is possible that the sample crystallized on the Moon. However, this would require conditions that are to be seen in the lunar specimens that have been collected so far. For example, the sample would have to crystallize very deep within the lunar mantle. Furthermore, it is believed that the composition of the Moon at these depths is quite different from what was observed in a rock pattern.
As a result, the simplest explanation is that it is a terrestrial rock that appeared on the moon, a finding likely to create some controversy. This is inevitable because this is the first Hadean pattern of this species to be found, and the place of its discovery will also likely contribute to the factor of infidelity.
However, Kring expects more samples to be found, as Hadean's rocks probably rusted the lunar surface during the late heavy bombing. Perhaps when the mission with the crew begins to travel to the moon in the coming decade, it will come to many of the oldest patterns of earthy rocks.
The study was made possible thanks to the support provided by NASA's Virtual Research Institute for Solar Research (SSERVI) as part of a joint venture between LPI and NASA's Johnson Space Center.