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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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Scientists Reform Face Of Another Human Ancestor

Now, Scientists have come up with a reformed face of a human ancestor

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human, ancestor, scientists, sculpture
This image shows a preliminary portrait of a juvenile female Denisovan based on a skeletal profile reconstructed from ancient DNA methylation maps. IANS

Exactly what our Denisovan relatives who lived 100,000 years ago might have looked like had been anyone’s guess for a simple reason – the entire collection of Denisovan remains includes a pinky bone, three teeth, and a lower jaw. Now, Scientists have come up with a reformed face of a human ancestor.

Now they have got a face. Using genetic data, scientists have now produced reconstructions of these long-lost relatives.

“We provide the first reconstruction of the skeletal anatomy of Denisovans,” said study author Liran Carmel of the Hebrew University of Jerusalem in Israel.

“In many ways, Denisovans resembled Neanderthals, but in some traits, they resembled us, and in others they were unique,” Carmel said.

Overall, the researchers identified 56 anatomical features in which Denisovans differed from modern humans and/or Neanderthals, 34 of them in the skull, according to a report published in the journal Cell.

For example, the Denisovan’s skull was probably wider than that of modern humans or Neanderthals. They likely also had a longer dental arch.

Rather than relying on DNA sequences, the researchers extracted anatomical information from gene activity patterns.

human, ancestor, scientists, sculpture
Using genetic data, scientists have now produced reconstructions of these long-lost relatives.
IANS

Those gene activity patterns were inferred based on genome-wide DNA methylation or epigenetic patterns.

To test the method the researchers developed, they first applied it to two species whose anatomy is known: the Neanderthal and the chimpanzee.

They found that roughly 85 per cent of the trait reconstructions were accurate in predicting which traits diverged and in which direction they diverged.

By focusing on consensus predictions and the direction of the change, rather than trying to predict precise measurements, they were able to produce the first reconstructed anatomical profile of the little-understood Denisovan.

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The evidence suggests that Denisovans likely shared Neanderthal traits such as an elongated face and a wide pelvis.

It also highlighted Denisovan-specific differences, such as an increased dental arch and lateral cranial expansion, the researchers said.

“Studying Denisovan anatomy can teach us about human adaptation, evolutionary constraints, development, gene-environment interactions, and disease dynamics,” Carmel said. (IANS)