2023-10-25 09:23:33
Updated Wednesday, October 25, 2023 – 09:23
The hypothesis that the asteroid was ejected from the lunar surface after the impact of a meteorite is gaining strength.
Artistic recreation of the asteroid Kamo’oalewa.EP
A team of astronomers has found a new clue that an asteroid near the Tierra recently discovered, Kamo’olawewait could be a piece of the Luna.
They hypothesized that the asteroid was ejected from the lunar surface during a meteorite impact and discovered that an unusual trajectory could have allowed Kamo’oalewa to enter orbit around the asteroid. Sol while remaining close to the orbits of the Earth and the Moon.
The research team details their findings in the Oct. 23 issue of the journal Communications Earth & Environment. Kamo’oalewa has been the subject of several astronomical studies in recent years. As a result, a Chinese mission that will launch in 2025 will land on the asteroid and return samples to Earth.
“Elements of this space body can give us information about the formation of Earth’s moon and improve our knowledge of near-Earth asteroids,” he said in a statement. Aaron Rosengrenprofessor in the Department of Mechanical and Aerospace Engineering at the University of California, San Diego, and one of the lead authors of the article.
Until now, only distant asteroids beyond the orbit of Mars were considered a source of near-Earth asteroids, he said. Renu Malhotra, professor of planetary sciences at the University of Arizona and also lead author of the paper. “We are now establishing that the moon is a more likely source of Kamo’oalewa,” Malhotra said.
The implication is that there are still many more lunar fragments to be discovered among the population of near-Earth asteroids.
Kamo’oalewa is unusual because it is a quasi-satellite of Earth, a term used for asteroids whose orbits are so similar to Earth’s that they appear to orbit the Earth even though they actually orbit the sun. The other peculiar aspect of Kamo’oalewa is the length of time it has been in this type of orbit, he said. José Daniel Castro-Cisneroslead author of the study and a graduate student in the Department of Physics at the University of Arizona, who is co-advised by Rosengren.
The asteroid is expected to remain Earth’s companion for millions of years, repeatedly transitioning between its current quasi-satellite state and horseshoe-shaped co-orbital motion, Castro-Cisneros said.
So how did it get here? The research team wanted to determine the feasibility of a detached piece of moon entering this quasi-satellite orbit, a phenomenon that is highly unlikely, Malhotra said. Moon fragments that have enough kinetic energy to escape the Earth-Moon system They generally have too much energy to land in quasi-satellite orbits similar to Earth’s, he said.
When the team developed numerical simulations that accurately explain the gravitational forces of all the planets in the solar system, they discovered that there was a 6.6% chance that some lunar fragments could reach co-orbital orbits, and an even rarer probability – 0.8 percent – of the occurrence of transient motion like that of Kamo’oalewa.
“The analysis and design of modern space missions has been using unusual space highways for years. We wanted to know how Kamo’oalewa fit in,” Rosengren said.
Throughout its history, the Moon has been bombarded by asteroids, which is evident in the numerous impact craters that remain on its surface. These impacts cause lunar material to be ejected from the moon’s surface, but most of that material usually falls back onto the moon. Some of the ejected materials become meteorites and fall to Earth.
But a small fraction could escape the gravity of both the Moon and Earth and end up orbiting the Sun like other near-Earth asteroids. The numerical simulation suggests that Kamo’oalewa could be one of the even smaller fractions that managed to enter the Earth’s co-orbital space, which is difficult to access.
The study’s findings could help better understand near-Earth asteroids, which are considered a danger to the Earth. More detailed studies of Kamo’oalewa to determine the origin of the asteroid from a specific impact crater on the Moon will provide useful information on the mechanics of the impact.
In the future, Castro-Cisneros said the team plans to identify the specific conditions that allowed Kamo’oalewa’s orbital path. The group also intends to work to deduce Kamo’oalewa’s exact age, he said.
“We need more information to say with certainty that Kamo’oalewa is indeed a fragment of the moon,” Rosengren said, “and a space mission to this unique celestial body is warranted.”
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