Already in the coming days, the Earth will lose its mini-moon. We are talking about asteroid 2024 PT5, which was temporarily captured by its gravity.
What are mini moons
From time to time our planet can acquire mini-moons. They are near-Earth objects that move along horseshoe-shaped trajectories and approach the Earth with low relative velocity. As a result, their geocentric energy becomes negative for some time. Quite often such objects do not have time to make a single orbit around the Earth, after which they leave its vicinity.
An example of such a mini-moon is the small object 2022 NX1. It became a temporary satellite of our planet twice in 1981 and 2022. Some astronomers speculated that 2022 NX1 may be a spent rocket stage. But observations have not confirmed this theory.
We can also mention the tiny asteroid 2006 RH120, whose diameter is only a couple of metres. In 2006-2007, it was a temporary satellite of the Earth and managed to make four orbits around it, after which it switched to a heliocentric orbit.
Second Moon for 56 days
Now the status of a mini-moon has been transferred to asteroid 2024 PT5. It was discovered on 7 August 2024, by telescopes automated system ATLAS. Its diameter is estimated at 11 metres. Presumably, 2024 PT5 is part of the Arjuna family of near-Earth asteroids.
After astronomers estimated the orbital parameters of 2024 PT5, it became clear that on 29 September it will be temporarily captured by Earth’s gravity. Thus, formally our planet has a second natural satellite.
However, the stay of 2024 PT5 in this status turned out to be quite short. In the next few days, the asteroid will leave the sphere of Earth’s gravity. This will happen on 25 November, after which the Moon will again become the only natural companion of our planet.
Radar observations 2024 PT5
However, although very soon 2024 PT5 will no longer be a mini-moon, we will still see it. On 9 January 2025, the asteroid will approach our planet at a distance of 1.8 million km. The visit poses no danger to Earth – this distance is almost five times the distance to the Moon. NASA is already preparing for the coming meeting, intending to conduct radar observations of the asteroid with the help of the Goldstone complex. They will help determine its shape and origin.
The fact is that immediately after the discovery of 2024 PT5, there were speculations that it might actually be a spent rocket stage. Subsequent analyses have shown that this is unlikely and the object is most likely of natural origin. However, there is a rather interesting possibility that it could be a large chunk of rock ejected from the surface of the Moon as a result of an asteroid impact. Radar observations will help to determine whether this is the case or not.
As for the asteroid, after the approach in January 2025, it will leave the vicinity of the Earth and continue its orbit around the Sun. The next time 2024 PT5 will approach our planet will be in 2055.
