A celestial visitor is about to grace our skies, albeit briefly. Earth is set to play host to a "mini-moon," the newly discovered asteroid 2024 PT5, which will be caught in our planet's gravitational embrace from September 29 to November 25. This temporary celestial dance, as described by astronomers, is a rare occurrence detailed in the Research Notes of the American Astronomical Society.

First glimpsed on August 7 through the eyes of the South Africa-based ATLAS observatory, 2024 PT5 is estimated to be around 37 feet in diameter, though its true size remains a subject for further observation. The asteroid could span anywhere from 16 to 138 feet, potentially larger than the Chelyabinsk meteor that lit up the skies over Russia in 2013, causing widespread damage and injury.

As a mini-moon, 2024 PT5 poses no threat of collision with Earth in the immediate future. It will orbit at a distance of approximately 2.6 million miles, a tenth of the way to the moon. The term "mini-moon" encompasses two types of events: long episodes where asteroids become temporarily captured orbiters, circling Earth for a year or more, and short episodes like 2024 PT5's, where the asteroid doesn't complete a full orbit around our planet.

Earth has had other fleeting mini-moon companions, such as Asteroid 2020 CD3, which was detected in February 2020 and left a few months later, only to be revealed as a long-capture mini-moon that had been orbiting Earth undetected for years.

The capture of an asteroid as a mini-moon is a delicate process, requiring the right speed and trajectory to be gently pulled into Earth's orbit. According to Robert Jedicke, an expert on solar system bodies, the likelihood of an asteroid becoming a mini-moon is independent of its size or mass and depends solely on its approach speed and angle relative to the Earth-Moon system.

Asteroid 2024 PT5 hails from the Arjuna asteroid belt, a collection of small asteroids with orbits akin to Earth's. Jedicke suggests that there might be a dishwasher-sized minimoon in the Earth-Moon system at any given time, but their detection is a challenge, with most remaining undiscovered during their brief tenure.

De la Fuente Marcos and his team plan to observe 2024 PT5 using powerful telescopes in the Canary Islands to gather more data. However, this mini-moon will be too small and dim for amateur astronomers to spot with telescopes or binoculars.

After its 56.6-day visit, the sun's gravitational pull will guide 2024 PT5 back to its regular orbit. It is expected to make a close approach to Earth on January 9, 2025, before departing until its next return in 2055. When it does, astronomers predict it will once again don the title of mini-moon for a few days in November 2055 and then for a few weeks in early 2084, a testament to the enduring yet fleeting nature of Earth's celestial encounters.