Asteroid 2024 PT5 becomes Earth’s temporary mini-moon, orbiting for two months before escaping, observed only by professional telescopes.

This fall, the cosmos will be treated to a phenomenon so rare that it will attract the passion of space enthusiasts and astronomers alike-the Earth will temporarily get a new moon. Asteroid 2024 PT5, the small rock from the Arjuna asteroid belt, is going to be a “mini-moon” that is temporarily trapped by Earth’s gravitational pull from September 29 until November 25. This space phenomenon will not be visible to the naked eye, but this temporary visitor will surely give scientists a great time and exciting opportunities to research, and even some equipped with professional telescopes. The Phenomenon of Mini-Moons

A mini-moon is not a common occurrence, but on the other hand, it’s not completely impossible either. These objects, which are usually small asteroids, sometimes get caught within the Earth’s gravitational field for some time, then orbit the said planet before eventually getting thrown back into space. While Earth’s permanent moon has been a faithful companion for billions of years, mini-moons are much shorter-term events. They are temporary visitors that are generally overlooked, coming and going with little publicity. One such great example is the asteroid 2024 PT5. It is set to remain in orbit for nearly two months, one of the longest-lasting mini-moons scientists have ever observed.

Asteroid 2024 PT5 was spotted on August 7, 2024, by NASA’s Asteroid Terrestrial-impact Last Alert System (ATLAS), an advanced telescope network in the making to provide precise identification of potentially hazardous near-Earth objects. Though 2024 PT5 does not pose a threat to Earth, its novelty has attracted so much attention to its temporary status as a mini-moon. This asteroid is not so big, measuring around 33 feet wide, but it is big enough to pique astronomers’ interest in the research about these rare gravitational interactions.

A Brief but Utterly Fascinating Encounter

There’s something somewhat fascinating about the origin and orbit of asteroid 2024 PT5. 2024 PT5 comes from the Arjuna asteroid belt group of objects following an orbit close to Earth and is on course to pass by close to our planet. It will not, however, fully orbit Earth as astronomer Dr. Jennifer Millard, host of the Awesome Astronomy podcast, explains: It is almost predictable and yet mysterious how Earth’s gravity can catch even a relatively small and slow-moving asteroid, like 2024 PT5, pulling it in and trapping it there for some time in orbit. Scientists comment that when this kind of asteroid is moving at some 2,200 mph (3,540 km/h), earth’s gravity becomes an important enough force to turn the asteroid into a temporary moon. Mini-moons have come and gone before, although many likely escaped detection. Some even return. For instance, the asteroid 2022 NX1 became a mini-moon in 1981 and again in 2022. And while 2024 PT5 is on its way out, it’ll come back around Earth’s orbit again in 2055.

Viewing the Mini-Moon

Asteroid 2024 PT5 will not be visible to the naked eye. It’s tiny and has a dull composition, making it invisible to the naked eye. Even home telescopes or binoculars will not give a good view of the mini-moon. Professional telescopes will have to be used to observe this celestial body, though its movements will be captured and put up online for space enthusiasts to enjoy. As Millard himself pointed out, this reminds one of how much has not been discovered in our solar system, emphasizing that “this asteroid was only discovered this year.”

NASA and other space agencies will of course make the best of this opportunity to closely survey 2024 PT5 to gain valuable data about its composition, trajectory, and how it interacts with Earth’s gravitational field. These mini-moons represent a perfect natural experiment for scientists who would want to better understand the dynamical vicissitudes around near-Earth objects and the forces controlling their orbits.

A Cosmic Reminder

Though asteroid 2024 PT5 will pass for a relatively short period, the way it always reminds us of how dynamic our solar system is is remarkable. Earth lives in an ocean of shifting celestial bodies; asteroids, comets, and other space objects often pass close to the Earth or interact with it. Although asteroid 2024 PT5 won’t be as talked about as other, more dramatic goings-on in space, it remains a fascinating reminder that there is much complexity and beauty in the cosmos.

As we see this mini-moon zip by Earth, we are reminded once again of what astronomy has in store for the universe. From NASA’s ATLAS system catching distant asteroids to astronomers sharing their findings with the world, our developing ability to observe and understand the cosmos inspires wonder and amazement. For those who missed this mini-moon, though, further cosmic surprises wait in store: 2024 PT5 will return to Earth’s neighborhood again in 2055.