It follows the earth around the sun, but don’t call it the moon – internationally

Space is vast and lonely. It is quite understandable, then, that a little rock decides to accompany Tera it’s Takes In your annual circumnavigation around Sol.

This 165-foot-tall rock was discovered in 2016 by the Hunter Asteroid Telescope. Pan Stars 1from Hawaii. The Hawaiian name for this eccentric entity, (469219) Kamo’oalewa, means “swinging celestial body”. As it orbits frequently around the Earth, this shy object never gets close to 9 million miles, which is 38 times farther than the Moon, and moves away up to 25 million miles before returning much closer. Then.

Orbital Waltz calculations indicate that it has begun to track our planet relatively steadily. about a century ago And it will continue to orbit the Earth for several centuries. But where did Kamwalewa come from? It is difficult to study the object with telescopes due to its small dimensions and its tendency to hide in shadows.

But in an article published on Thursday, the eighteenth, in Earth and Environment Communications, a team of scientists reports that they may have solved the mystery. Astronomers, observing Kamo’oalewa for brief moments when illuminated by the sun, discovered that it appears to be made of the same type of frozen rocky material found on the moon’s surface.

“My first reaction to the 2019 notes was that I might have been wrong,” he said. Benjamin Sharkey, a graduate student at the University of Arizona and lead author of the study.

It was expected that Kamo’oalewa It was composed of minerals commonly found in asteroids. But additional observations this spring made clear that “the data doesn’t care what we thought,” Sharkey said. Kamo’oalewa actually looked like an extremely small version of the moon, and upon making this discovery, he said, “I was excited and confused at the same time.”

Based on its orbit and composition, Kamo’oalewa may be part of the moon, separated by a meteorite impact in the past.

Kamo’oalewa may look like a miniature moon, but it isn’t. Unlike the Moon, which is gravitationally bound to the Earth, Kamo’oalewa is gravitationally bound to the Sun. If you suddenly make Earth disappear, Kamo’oalewa will continue to orbit our star. It’s what’s known as a quasi-satellite. Astronomers know of four others still near Earth, but Kamo’oalewa has a more stable orbit.

In April 2017, Kamo’oalewa was well lit when the Earth was between the nearby satellite and the sun. Astronomers observed this with two telescopes in Arizona – the Big Eyed Telescope and the Lowell Discovery Telescope – and used the reflected light to identify your minerals. They have seen many silicates and minerals found in rocky bodies throughout the solar system – and subsequent observations have confirmed that Kamo’oalewa’s silicate is very similar to those on the Moon.

That may have been a coincidence, and so the study’s authors suggested other possible origin stories: Kamo’oalewa could have been an asteroid captured with a composition similar to the moon, or a portion of an asteroid torn apart by the moon’s gravitational pull. the system.

The team’s data “further supports a lunar origin,” said Hannah Sargent, a planetary scientist at the University of Central Florida who was not involved in the study.

This semi-satellite may not be alone: ​​the orbits of three other near-Earth objects are similar enough to those of Kamo’oalewa to indicate that they may have come from the same catastrophic event. But for now, Sargent said, “there is not yet enough evidence to reliably confirm how these things came about.”

“The only way to be sure is to send a spacecraft into this small body,” said Paul Byrne, a planetary scientist at Washington University in St. Louis, who was not involved in the study. The Chinese space agency plans to land on it and collect samples to return to Earth later this decade.

“Until then, we are left with the possibility that on our journey through space, we will be accompanied by impact debris that punctures the moon,” Byrne said. “And that’s really cool.” / Translated by LVIA BUELONI GONAALVES

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