Fragments of the alien world can be buried in the earth

NASA / JBL-Caltech / D. File (SSC) / Wikimedia

Scientists have long recognized that the Moon formed around 4.5 billion years ago when a protoplanet called Thea hit Earth. Fragments of that impact could be buried deep within our planet, suggests a new study.

The team of scientists has a new project on Thea’s impact on Earth, which led to the formation of the Moon: fragmentary remains of this planet can be found here Two layers of continental rocks Buried in the shield of our planet.

For decades, seismologists have been confused by two bubbles under West Africa and the Pacific Ocean, which have spread to the center of the earth. At a height of a thousand kilometers and several times the width, “they are the tallest thing in the earth’s mantle,” he said. Qian Yuan, PhD student in seismology Arizona State University, In statements Scientific journal.

Earthquake seismic waves Suddenly decreases When they pass through these layers, it means that they are dense and chemically different from the surrounding mantle rock.

Large Low Speed ​​Provinces (LLSVP) may simply exist Deep crystallized The first magma on Earth may be the ocean or Dense rock pools of the old mantle He escaped the shock of the impact of the formation of the moon.

However, based on new evidence and isotopic models, Yuan believes it to be LLSVP. The gut of alien influence.

Earthquake footage observed magma worms feeding on LLSVP on volcanoes on both islands. Over the past decade, many scientists have discovered the isotopic record of volcanic radioactive elements on the islands The first 100 million years From the history of the earth.

Impact theory was developed in the 1970s to explain the lunar drought and the absence of a high iron core: during a catastrophic impact, volatile substances such as water would have evaporated and escaped, while a ring of low density rock formed in the collision and eventually formed the moon. This theory affected the size of Mars, but co-author of Juan, a recent work by an astronomer Steven desh, Said Thea As big as the earth.

Desh and his colleagues measured the ratios of hydrogen to deuterium, a heavy isotope of hydrogen. Some models of the Moon contained more light hydrogen than rocks on Earth. To capture and retain as much light hydrogen, Thea Dev der Sido is huge, The researchers proposed in the 2019 study.

It must have been very dry because any water would have raised the general level of deuterium. Such a large and dry protoplanet would be covered with a core poor in iron and armor rich in iron.

Yuan’s model suggests that after the collision Thea’s center will quickly merge with Earth. Simulations have shown that mantle rocks are 1.5% to 3.5% denser than those on Earth. Mountains near the center.

A large Thea also explains the size of the LLSVPs, which are six times the mass of the Moon.

If Thea’s remains were deep in the Earth’s mantle, they wouldn’t be alone. Seismic experts are increasingly observing In small ultra-dense pockets The deep mantle material, only a few hundred kilometers wide, is typically found near the edges of LLSVP.

The iron-rich cores of other small planets that struck early Earth may have been submerged in water. So Thea can be a grave in a planetary cemetery.

Scientists gave this hypothesis was discussed at the lunar and planetary science conference last week.

Maria campos

Maria Campos, ZAP //