(ORDO NEWS) — The moon may have formed immediately after a catastrophic impact that tore off a piece of the Earth and threw it into space, according to a new study.
Since the mid-1970s, astronomers have believed that the Moon may have formed from a collision between the Earth and an ancient Mars-sized protoplanet called Theia; a colossal collision would have created a huge debris field from which our lunar satellite slowly formed over thousands of years.
But a new hypothesis, based on higher-resolution supercomputer simulations than ever before, suggests that the Moon’s formation may not have been a slow and gradual process, but took place in just a few hours.
The scientists published their findings October 4 in The Astrophysical Journal Letters.
“We’ve learned that it’s very difficult to predict what resolution you need to reliably simulate these violent and complex collisions – you just have to keep testing until you find that increasing the resolution further has no effect on the answer you get,” said Jacob Kegerrais, computational cosmologist from Durham University in England. Living Science.
Science Scientists first received information about the creation of the moon after the return of the Apollo 11 mission in July 1969, when NASA astronauts Neil Armstrong and Buzz Aldrin delivered 47.6 pounds (21.6 kg) of moon rock and dust to Earth.
The samples are dated to about 4.5 billion years ago, indicating that the Moon formed during a turbulent period about 150 million years after the formation of the solar system.
Other clues indicate that our largest natural satellite was born from a violent collision between Earth and a hypothetical planet that scientists have named after the mythical Greek titan Theia – the mother of Selene, goddess of the moon.
This evidence includes similarities in the composition of lunar and terrestrial rocks; The rotation of the Earth and the orbit of the Moon have the same orientation; high total angular momentum of two bodies; and the existence of debris disks elsewhere in our solar system.
But exactly how the cosmic collision played out is a matter of debate. The traditional hypothesis suggests that when Theia crashed into Earth, the impact with the planet shattered Theia into millions of pieces, turning her into flying debris.
The broken remains of Theia, as well as several vaporized rocks and gas torn from our mantle of the young planet, slowly merged into a disk, around which the molten sphere of the Moon merged and cooled over millions of years.
However, some parts of the picture remain elusive. One unresolved question: why, if the Moon is mostly made of Theia, do many of its rocks bear a striking resemblance to those found on Earth?
Some scientists have suggested that more of the evaporated Earth rocks went into creating the Moon than the crushed remains of Theia, but this idea has its own problems, such as why other models suggest that the Moon, made up mostly of broken Earth rocks, would have a completely different orbit. than what we see today.
To explore different possible scenarios for the formation of the moon after the impact, the authors of the new study turned to a computer program called SPH with interdependent fine-grained tasks (SWIFT), which is designed to accurately simulate the complex and constantly changing network of gravitational and hydrodynamic forces acting on a large amount of matter.
Completing such an exact task is not an easy computational task, so the scientists used a supercomputer to run a program: a system called COSMA (short for “cosmolo”). gy machine”) at Durham University’s Center for Distributed Research Using Advanced Computing Power (DiRAC).
By using COSMA to simulate hundreds of Earth-They impacts at varying angles, rotations and velocities, lunar spotters were able to model the aftermath of the astronomical crash at higher resolution than ever before.
The resolution in these simulations is determined by the number of particles used in the simulation. For giant collisions, standard simulation resolutions typically range from 100,000 to 1 million particles, Kegerreis says, but in the new study, he and his colleagues were able to simulate up to 100 million particles.
“With a higher resolution, we can study more details similar to how a large telescope allows you to take higher resolution pictures of distant planets or galaxies to reveal new details,” Kegerreis said.
“Secondly, and perhaps even more importantly, using too low a resolution in a simulation can lead to misleading or even simply wrong answers,” he added.
“You can imagine that if you build a model car out of toy blocks to simulate how a car can break down in a crash, then if you only use a few dozen blocks, it can just crack down the middle perfectly. But with a few thousand or millions, you can start to crumple and break it more realistically.”
Higher resolution simulations left researchers with a Moon that forms d over the course of hours from ejected chunks of Earth and debris from Theia, proposing a one-stage formation theory that offered a clear and elegant answer to the Moon’s apparent properties, such as its wide, inclined orbit; its partially melted interior; and its thin bark.
However, researchers will have to study rock and dust samples recovered from deep below the Moon’s surface the target of NASA’s future Artemis missions before they can confirm just how mixed its mantle could be.
“Even more samples from the surface of the Moon could be extremely useful for new and more reliable discoveries about the composition and evolution of the Moon, which we can then trace to a model like ours,” Kegerrais. said.
“Missions and explorations like these and more are constantly helping us rule out more possibilities and narrow down the actual history of both the Moon and Earth, and learn more about how planets form throughout and outside our solar system.”
Such studies could also shed light on how the Earth formed and became a habitable planet.
“The more we learn about how the Moon formed to be, the more we learn about the evolution of our own Earth,” study co-author Vincent Ecke, an associate professor of physics at Durham University, said in a statement.
“Their stories are intertwined and can be mirrored in stories about other planets that have changed as a result of similar or very different collisions.”
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