Earth recently captured a small asteroid known as 2024 PT5, temporarily transforming it into a second moon. This rare event was confirmed by astronomers from Massachusetts Institute of Technology (MIT) and the Complutense University of Madrid, offering a glimpse into these elusive “mini-moons” that Earth occasionally holds within its orbit. However, Earth’s newly acquired companion is not here to stay. In a matter of weeks, by mid-November, 2024 PT5 is expected to slip out of Earth’s gravitational hold and resume its journey around the sun.

How Scientists Discovered 2024 PT5

This asteroid was first identified on 7 August 2024 by NASA’s Asteroid Terrestrial-impact Last Alert System (ATLAS) at Hawaii’s Haleakala Observatory. Subsequent observations were conducted by astronomers from the Complutense University using a high-powered telescope located in Sutherland, South Africa. While such temporary moons have been observed before, they are typically hard to detect due to their small size and fleeting appearance.

Richard Binzel, a renowned astronomer at MIT, highlighted that these transient moons are easier to track now with advanced telescope technology. “We’re only starting to observe these small objects with enough regularity to learn more about them,” he explained. As Earth.com reported, the capture of 2024 PT5 has piqued the interest of astronomers eager to study near-Earth objects in greater depth.

Why Mini-Moons Are Important

While our primary moon spans an impressive 2,159 miles in diameter, 2024 PT5 is a mere 37 feet across — rendering it invisible without a telescope of at least 30 inches in diameter. The limited visibility of these mini-moons shows us the challenge in observing them. As noted by William Blackmore, Planetarium Director and Astronomy Instructor at Mt. Hood Community College, “each mini-moon offers a unique learning opportunity.” He pointed out that by studying these objects, scientists can make better methods for tracking potential asteroid threats to Earth.

Potential for Future Exploration

While the chances of mining such asteroids remain distant, Blackmore envisions future missions using probes or satellites to monitor these fleeting visitors. Understanding mini-moons like 2024 PT5 could pave the way for intercepting larger asteroids in the future, a critical step in safeguarding Earth.
In a few short weeks, 2024 PT5 will leave Earth’s orbit.