Earth is about to gain a new ‘mini-moon,’ albeit temporarily. A recently discovered asteroid, named 2024 PT5, will be captured by Earth’s gravity and will orbit our planet from September 29 to November 25. After this, it will return to its heliocentric orbit around the sun.
The capture of an asteroid as a mini-moon requires very specific conditions: it must approach Earth at a slow speed and a close range. Asteroids must be within 2.8 million miles (4.5 million kilometers) and travel at speeds under 2,237 miles per hour (3,600 kilometers per hour).
Robert Jedicke, a specialist on solar system bodies at the University of Hawaii’s Institute for Astronomy, notes that size and mass do not influence the capture process. Only speed and trajectory matter. Asteroid 2024 PT5 originated from the Arjuna asteroid belt, known for small asteroids with orbits similar to Earth’s.
Jedicke adds that approximately one dishwasher-size mini-moon exists in the Earth-Moon system at any time. However, their detection is difficult, meaning many go unnoticed. At about 10 meters in diameter, 2024 PT5 is the largest captured object discovered so far.
Mini-moons can also originate from the main asteroid belt between Mars and Jupiter or be fragments of the lunar surface ejected by asteroid impacts. Understanding their origins helps scientists learn about crater formation and the distribution of lunar material.
Asteroid 2024 PT5 will return to its usual orbit around the sun after 56.6 days, influenced by the sun’s gravitational pull. It will not have any observable effects on Earth during its brief capture.
The asteroid is expected to make a close approach to Earth, coming within 1.1 million miles (1.7 million kilometers) on January 9, 2025. It will move away from our vicinity until its next predicted return in 2055.
In 2055, another mini-moon event is anticipated, lasting a few days in November, followed by an event in early 2084. These predictions allow astronomers to plan further observations well in advance.
The temporary capture of asteroid 2024 PT5 as a mini-moon provides a unique opportunity for further astronomical study. While it poses no threat to Earth, its brief presence will contribute to our understanding of such fleeting celestial events.
Continued observations and research on 2024 PT5 will enhance knowledge of asteroid behavior and the dynamics of mini-moons. These insights could be crucial for future studies and the monitoring of near-Earth objects.
