According to a new analysis, the asteroid known as Kamooalewa is the planet’s most stable quasi-satellite in terms of orbit, but while it is unlikely to qualify as a moon, it may, in reality, be a piece of our own. The asteroid, also known as 469219, was discovered in 2016 by astronomers at the University of Hawaii. This name is emerged from the Hawaiian language and is a mix of words that indicate “the,” “fragment,” “of,” and “to oscillate.”
The asteroid is 46 to 58 meters in diameter, equivalent to Italy’s Leaning Tower of Pisa or Disney World’s Cinderella Castle. As a result, while it has been designated as a Near-Earth Object (NEO) due to its proximity to the planet, it is not a Potentially Hazardous Asteroid (PHA), which must be at least 140 meters in size.
Its orbit and connection to Earth, though, are particularly fascinating. Kamooalewa is an Apollo-class asteroid, which means that its orbit around the Sun regularly brings it near Earth. The asteroid, however, is affected by the Earth’s orbit. It revolves around the Sun more closely than Earth, yet it frequently crosses outside Earth’s orbit.
It is more impulsive with planet’s gravity as it bobs about the Earth’s orbital plane in what NASA Center for NEO Studies at the Jet Propulsion Laboratory manager Paul Chodas characterized as a game of leapfrog. This is a process going on for about a century and is likely to continue for decades to come.
As a result, it is known as Earth’s “constant companion” and is regarded as the most outstanding example of a quasi-satellite.
Every year, the asteroid’s loops around Earth move forward or backward. Still, when they move forward or backward, Earth’s gravity is vital to change and hold onto the asteroid so that it never moves further away than about 100 times the distance of the Moon, Chodas said in 2016. “The same force keeps the asteroid from getting any closer than around 38 times the distance between it and the Moon. This little asteroid is engaged in a brief dance with Earth.”
The recent study, published in the academic journal Communications Earth & Environment, began in 2016 and examined the asteroid using the Large Binocular Telescope and the Lowell Discovery Telescope to perform a thorough examination, and discovered that the asteroid is reddened, referring to its specific pattern of reflected light, also known as a spectrum. It is unique, but the level of reddening is significantly more than that found in other asteroids in the inner solar system.
The researchers discovered it to be the closest match after analyzing lunar samples from the Apollo 14 mission. This suggests that Kamooalewa must have broken away from the lunar surface at some time.
But there’s another problem: although it’s conceivable, it’s also utterly unprecedented. “I searched through every near-Earth asteroid spectrum we had access to, and nothing matched,” said primary research author Ben Sharkey, a doctoral student at the University of Arizona, in a release, referring to the fact that there are no other known NEOs considered to have split from the Moon.
The astronomers had to take another observation of the asteroid after being uncertain for three years. COVID-19, on the other hand, shut down the telescopes required to observe it in April 2020, denying them another look. Kamooalewa is incredibly faint, 4 million times fainter than the brightest visible star in the sky. It would not be easy to see without a telescope. They finally saw Kamooalewa in the spring of 2021, and the puzzle began to fall into place.