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Scientists Found Earth’s Oldest Rock on Moon

The final impact event to affect this sample occurred about 26 million years ago, when an impacting asteroid hit the Moon

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Analysis of lunar samples from the Apollo 14 mission shows that a large impacting asteroid or comet hurtled a piece of Earth rock, about 4 billion years ago, on to the Moon’s surface.

An international team of scientists led by NASA’s Center for Lunar Science and Exploration (CLSE), found evidence that the impact jettisoned material through Earth’s primitive atmosphere, into space, where it collided with the surface of the Moon (which was three times closer to Earth than it is now) about 4 billion years ago.

The rock was subsequently mixed with other lunar surface materials into one sample.

The 2 gram fragment of rock was composed of quartz, feldspar, and zircon — all commonly found on Earth and highly unusual on the Moon.

Earth depletion
Earth depletion, Pixabay

“It is an extraordinary find that helps paint a better picture of early Earth and the bombardment that modified our planet during the dawn of life,” said David A. Kring, Principal Investigator at CLSE.

It is possible that the sample is not of terrestrial origin, but instead crystallised on the Moon.

That would, however, require the sample to have formed at tremendous depths, in the lunar mantle, where very different rock compositions are anticipated and in the reducing and higher temperature conditions characteristic of the Moon.

But chemical analysis of the rock fragment shows it crystallised in a terrestrial-like oxidised system, at terrestrial temperatures, according to research published in the journal Earth and Planetary Science Letters.

rocks
Earth’s oldest known evolved rocks result of asteroids. Pixabay

Further, the researchers revealed that the rock crystallised about 20 kilometres beneath the Earth’s surface 4-4.1 billion years ago. It was then excavated by one or more large impact events and launched into cislunar space.

Once the sample reached the lunar surface, it was affected by several other impact events, one of which partially melted it 3.9 billion years ago, and which probably buried it beneath the surface.

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The sample is therefore a relic of an intense period of bombardment that shaped the solar system during the first billion years. After that period, the Moon was affected by smaller and less frequent impact events.

The final impact event to affect this sample occurred about 26 million years ago, when an impacting asteroid hit the Moon, producing the small 340 meter-diameter Cone Crater, and excavating the sample back onto the lunar surface where astronauts collected it almost exactly 48 years ago (January 31-February 6, 1971), Kring explained. (IANS)

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Space Rock Twice the Size of Big Ben to Skim Past Earth: NASA

"These asteroids have been well observed and their orbits are very well known," said NASA's Planetary Defence Officer Lindley Johnson

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University of Iowa, Radiation, Sun
FILE - Tourists take pictures of a NASA sign at the Kennedy Space Center visitors complex in Cape Canaveral, Florida, April 14, 2010. VOA

NASA is closely monitoring an asteroid with an estimated diameter of about 755 feet — larger than the Golden Gate Bridge tower or more than twice the height of London’s Big Ben — that is currently heading towards Earth and is expected to skim past the planet on Monday.

Flying towards the planet at a speed of over 61,500 miles per hour, the Near-Earth Object (NEO) is big enough to destroy an entire city if collides with the Earth.

The approaching asteroid has been identified as “2020 AQ1”.

According to Express.co.uk, the asteroid will make its closest Earth approach on January 20 at around 2.54 am EST (1.24 pm India time).

The European Space Agency (ESA) has identified 21,655 NEO asteroids and 109 NEO comets.

NASA
Earth’s view from moon’s surface. Pixabay

The asteroid will hurtle past the planet on what astronomers have described as a “close approach” trajectory.

NASA’s trackers estimate the rock measures somewhere in the range of 328 feet -754 feet across – more than twice the height of London’s Big Ben.

Last September, a pair of asteroids flew past the Earth.

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“These asteroids have been well observed and their orbits are very well known,” said NASA’s Planetary Defence Officer Lindley Johnson.

“Both of these asteroids are passing at about 14 lunar distances from the Earth, or about 3.5 million miles away, but small asteroids pass by Earth this close all the time,” he added. (IANS)