In addition to the Moon, it appears that Earth has another celestial companion, something that has captured the attention of astronomers for years. If we were to break it down, the size of Kamoʻoalewa, essentially a giant asteroid, is much smaller than our Moon. In fact, it is a little less than the size of the Statue of Liberty.
Additionally, Kamoʻoalewa is also known as a “second moon” due to its orbit which, more so optical, appears to encircle the Earth. In actuality, Kamoʻoalewa, together with Earth, orbits the sun. Therefore, it is more accurately referred to as a quasi-satellite.
After a period of time, researchers found that the aforementioned asteroid had originated closer to the Moon than one might think. In fact, it derived from the Giordano Bruno crater, resting on the Moon surface. This information came to light recently as a research paper published in the journal Nature Astronomy, proposed theory that rock materials blasted from the Moon surface millions of years ago, might have been hit, could have gone off orbit. And this, could have resulted in the formation of an asteroid like Kamoʻoalewa.
The Pan-STARRS telescope array, stationed in Hawaii, was the first establishment to spot Kamoʻoalewa back in the year of 2016. A peculiar thing was that its light signature was unlike that of any other asteroid. Rather, it bore a strong resemblance to the Moon.
The article says that one piece of evidence is supporting their bold idea, proposed back in 2021 by the University of Arizona, that it’s possible the sample is a piece of moon rock.
The giordano bruno crater link
The Giordano Bruno Crater is a large scar on the dark side of the moon. It is believed to be 1 to 10 million years old. This is rather young when it comes to the age of the universe. The crater is 22 kilometers in diameter which was formed by the impact of an asteriod that was roughly one mile wide. The asteriod was able to spin off and debris into space. The impact was so strong that and moon’s gravity was unable to pull it back.
Simulations show that it is possible for a rock the size of Kamoʻoalewa to be within reach and captured Kamoʻoalewa’s orbit. It is a rare space rock that is located close to Earth. What is even more interesting is that it’s spectrum, the light it reflects, resembles moon soil more than it does any other asteroid that is closer to us. This means that every time this asteroid is observed, we are looking at a piece of the moon.
China’s Tianwen-2 mission to visit Kamoʻoalewa
We won’t have to wait too long to find out. China’s Tianwen-2 mission is due to visit the asteroid in a few years and return with samples. It will be the first mission to examine deep an asteroid of such small dimensions—objects the size of a small room which astonishingly are the most abundant in our solar system and yet the most mysterious.
Scientists will be able to confirm whether the material is indeed lunar in origin. If so, Kamoʻoalewa will become the first asteroid which is believed to be captured in an orbit close to the Earth and was formed from the Moon. Such a find will not only answer a celestial riddle but will also enhance our understanding of the processes that govern the formation of planets, moons and the small orbiting bodies.
As with all our neighbors in space, Kamoʻoalewa is a reminder of the rather complex and surprising history that all of them tell. From a crater hiding behind the Moon to a relic that can be found in Earth’s atmosphere.