This month, starting from September 29, our planet will be accompanied by a new celestial companion: the small asteroid 2024 PT5, which will temporarily become a mini-moon of Earth. Unlike our Moon, which has been orbiting us for about 4 billion years, 2024 PT5 will stay nearby for only a short period of about two months before returning to its position in the Arjuna asteroid belt, an area located at an average distance of about 150 million kilometers from the Sun.
A team of scientists specializing in the study of mini-moon events has recently identified this imminent gravitational capture.
By regularly monitoring near-Earth celestial objects, they noticed the dynamic peculiarities of 2024 PT5, making it an ideal candidate for this rare phenomenon.
Asteroids in the Arjuna belt follow orbits similar to Earth’s, occasionally allowing these objects to approach up to about 4.5 million kilometers from our planet.
Mini-moons form when an object enters a temporary orbit around Earth. In these cases, the relatively low speed of the asteroid, which in the case of 2024 PT5 is about 3,540 km/h, combined with a negative geocentric energy, allows the object to be captured by Earth’s gravitational field.
This process will begin next weekend and last for two months, during which the asteroid will remain bound to Earth without completing a full orbit.
Mini-moon events are divided into two categories: long captures, which can last for years and during which the asteroid completes multiple revolutions around Earth, and short captures, where the celestial body does not even complete one orbit and the encounter lasts only a few weeks or months. 2024 PT5 falls into the second category, with a short capture of two months before being expelled from Earth’s orbit due to gravitational disturbances caused by the Sun.
The Arjuna asteroid belt is a regular source of potential mini-moons. In recent history, only two objects have been subject to long captures: RH120 in 2006 and CD3 in 2020.
Additionally, there are examples of short captures such as VG in 1991, NX1 in 2022, and now, PT5 in 2024.
Although there are other cases of captures not yet published, these observations offer valuable study opportunities.
Unfortunately, 2024 PT5 will not be visible to most amateur observers.
Its small size and low brightness make it difficult to observe with common telescopes or binoculars.
However, the object could be detected through professional telescopes equipped with advanced instruments such as CCD or CMOS detectors and with a minimum diameter of 30 inches.
Scientists plan to conduct spectroscopic and photometric observations to gather valuable data on the composition and dynamic properties of this asteroid.
After its stay as a mini-moon, the asteroid 2024 PT5 will return to its original orbit around the Sun, continuing to be part of the near-Earth asteroid population.
Although its presence will go unnoticed by most people, its study will provide new information on gravitational capture processes and the orbital dynamics of these small celestial bodies.
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