Last year, two amateur astronomers, Grzegorz Duszanowicz and Jordi Camarasa, discovered an object partially orbiting Earth. That thing is a mini-moon, and is said to return sometime in the future.
The mini-moon is named 2022 NX 1 because it is likely an asteroid temporarily captured by Earth's gravity. But there is another possibility that is less interesting, namely that the mini moon could be the remnants of a rocket.
Then, a new scientific paper appeared confirming the natural status of 2022 NX 1, making it a mini-moon that is dropping by and may return in the future. There are also suggestions that the mini-moon may crash into Earth later this century.
Quoted from IFL Science, in addition to our large and crucial Moon, Earth occasionally gets other objects known as mini moons, which stray into its gravitational well and stay for a while.
It seems that this kind of thing has been happening since the birth of the Solar System, but only recently has anyone been able to detect it. One prominent example occurred recently with an object named 2020 SO.
The thing is, humanity's capacity to discover mini-moons coincided with a time when we indulged in trashing space by dumping thousands of artificial satellites and rocket pieces into Earth's orbit. This condition makes it difficult to distinguish whether it is a mini moon or space junk.
For example, 20 years ago an object named J002E3 was thought to be an asteroid. Later, however, it was discovered that J002E3 was debris from the Apollo 12 mission.
As a result, when amateur astronomers Duszanowicz and Camarasa discovered 2022 NX 1, they weren't sure if it was a celestial body. Fortunately, the scientific journal Astronomy and Astrophysics confirmed that the object is a mini-moon and revealed the true nature of the find, as well as its future prospects.
Mini Moon Discovery
2022 NX 1 was discovered on July 2 from the Moonbase South Observatory, Namibia, and is thought to have made its closest approach to Earth on June 26. There is a 1.2% chance of hitting Earth between 2075 and 2122, but it is not expected to cause widespread damage, although an explosion such as the Chelyabinsk, Russia meteor crash event is possible.
So far, 2022 NX 1 has been confirmed as an asteroid, probably of type K, and qualifies as a minimoon. A combination of observations shows that 2022 NX 1 has only been 'captured' by Earth (having negative geocentric energy) for 21 days. This time is not enough to complete one orbit, leading some astronomers to question its status as a minimoon, but it meets the official definition.
Interestingly 2022 NX 1 was previously detected at least twice in the 1980-1981 range. It is estimated that its orbit will return it to the same status for a period in 2051.
An additional fact, even though it is called a mini moon, is actually quite large compared to the large Moon. As an illustration, the length is equivalent to one to three giraffes.
"The discovery of 2022 NX 1 confirms that minimoons can be larger than a few meters and also have heterogeneous populations in terms of surface composition," the authors concluded.