What about the mysterious asteroid Kamo’oalewa that orbits the sun in an Earth-like orbit? Analyzes of the reflected light spectrum now show that the celestial body is made of a material similar to that of the Moon. Kamo’oalewa was likely created from parts from a previous asteroid impact on our satellite, scientists say.
The Earth-Moon system moves through space in the vicinity of many smaller celestial bodies: in our Solar System there is a brilliant community of near-Earth asteroids. Some of them travel in special orbits: they revolve around the sun in a similar way to the Earth. So they are called semi-satellites. Little is known about these NEOs, as they are very poorly lit and therefore difficult to observe.
In 2016, astronomers added the asteroid Kamo’oalewa to a well-known quasi-satellite: the PanSTARRS telescope in Hawaii was able to capture its subtle glow, which is about four million times fainter than the faintest star the human eye can detect. Look at the night sky. According to the data, the diameter of Camu Aliwa is about 100 meters. It revolves around the sun in an orbit that is only slightly different from the Earth and takes about a year in one orbit. With the current constellation, it always approaches Earth in April. The closest approximation is about 15 million km.
Interesting patterns in dim shimmer
In order to learn more about Kamo’oalewa, researchers working with Benjamin Sharkey of the University of Arizona in Tucson took a closer look at it. The Big Eyed Telescope and the Lowell Discovery Telescope located in Arizona were used. Their high sensitivity to light enabled the spectroscopy of the weak light reflected from the small celestial body. The scientists explained that based on the pattern of wavelengths, it was possible to draw conclusions about the properties of certain materials as well as comparisons with the light spectrum signatures of other celestial bodies.
As they reported, it became clear from the analyzes that the Kamo’oalewa composition is characterized by silicates. Scientists say that a slight shift in the reddish spectrum distinguishes Kamo’oalewa from known signatures from other asteroids in the inner solar system. “I’ve looked at every spectrum of near-Earth asteroids that we’ve been able to reach and none of them match the results,” Sharkey says. However, further comparisons showed that the patterns of light reflected from Kamo’oalewa are consistent with those of lunar rocks, the characteristics of which are known from samples from NASA’s Apollo missions.
Moon debris body?
As the researchers explain, this discovery now sheds light on the possible origin of this asteroid with a particularly similar orbit. “The Kamo’oalewa reflection spectrum supports the interpretation that it formed from lunar debris,” the scientists wrote. Specifically, an asteroid could once have hit the moon, shedding distant material, from which Kamo’oalewa then formed.
Investigations into Kamo’oalewa’s orbit as part of the study also support the asteroid’s origin in the Earth-Moon system. It differs from Earth only by a slight inclination and is in the special orphan state atypical of near-Earth asteroids. “It is very unlikely that a normal near-Earth asteroid would spontaneously oscillate in a semi-satellite orbit like that of Kamuwaliwa,” explains co-author Renu Malhotra of the University of Arizona.
However, some questions about the interesting celestial body remain unanswered. That’s why astronomers want to watch it.
Source: University of Arizona, Articles: Earth Communications and Environment, doi: 10.1038/s43247-021-00303-7