One of the oldest terrestrial rocks found on the. Moon
Scientists say they have identified one of Earth’s oldest terrestrial rocks. But the piece of rock in question was not found on Earth. It was brought back from the Moon along with other soil samples by astronauts on the Apollo 14 mission in 1971. According to researchers, it contains a fragment of ancient Earth’s crust, estimated to be about four billion years old.
Nearly 48 years after the astronauts of the Apollo 14 mission returnedóciliated from the Moon with a load of rocks collected there, geologists have determined that at least one of them originated from Earth’s. This is indicated by its chemical composition resembling rocks common on our planet.
A small fragment, weighing less than 2 grams, embedded in a larger piece of rock contains quartz, feldspar and zircon – minerals commonly found on Earth and quite unusual for the Moon. Chemical analysis revealed that the fragment was formed under Earth-like conditions and temperatures similar to those on our planet, rather than conditions on the Moon.
If the suspected piece of rock was formed on the Moon, conditions must have existed there in the past, which theórych scientists have so far not even thought while studying the próbki of the lunar soil. Perhaps the fragment originated in a strangely water-rich pocket deep beneath the surface of the ancient Moon. This can’t be ruled out, but the study’s authors believe it’s more likely that the rock formed in our planet’s crust and was ejected to the moon by one of the many meteorite impactsóin whichóre bombarded the early Earth.
According to scientistsów, a rock brought back to Earth by an astronautów of the Apollo 14 mission, was ejected from our planet about four billion years ago, when a large asteroid or comet struck a young, approximately 540-million-year-oldów years of Earth, sending rock fragments into space. Another argument of the researchers to support their concept is that the Moon was then much closer to Earth – about three times closer than it is today. This may have made it easier for a piece of Earth debris to get there.
– This remarkable discovery, whichóre helps us visualize a better picture of the young Earth and the bombardment, whichóre changed our planet in its early days, said David Kring of the Lunar and Planetary Institute.
Although geologists have previously discovered meteorites on Earth from the Moon, Mars and asteroids, this piece of rock is the first one thatóry was identified as an Earth meteorite on the Moon. Scientists have made a very thorough analysis of the rock fragment. The zircon found in it was a particularólnie useful because the mineral contains uranium, whichórego known period pópermeability allows for accurate dating, whichóre of koels indicated that the fragment was formed about 4-4.1 billion years ago.
Researchers believe that this small piece of rock was formed beneath the Earth’s surface at a depth of about 20 kilometersów, where it remained until a violent impact ejected it into space. A small excerpt hit this wayób to the moon, where successive meteorite impactsów melted it and buried it under the moon’s surface about 3.9 billion years ago. About 26 millionów years ago, during the re-bombardment of the Silver Globe, the fragment was brought to the surface and remained there until astronauts from the Apollo 14 mission picked it up – Such a concept was proposed by scientists in a publication.
Collected by Alan Shepard on February 6, 1971, the rock with the suspected chunk of earth – officially named 14321 – is one of the largest that the Apollo missions brought back from the Moon.