(Image via cnn.com)
Volunteer Writer: Emma Bowser
Email: ebowser@umassd.edu
On September 29, 2024, a small asteroid known as 2024 PT5 came within reach of Earth’s orbit and took up a temporary position as a “mini-moon.” The regular moon is still where it’s been since it was formed. It has a companion until November 25, 2024.
Usually, 2024 PT5 is about 93 million miles (150 million kilometers) from our Sun in the Arjuna asteroid belt. After it leaves Earth’s orbit, it will return to its usual place in space.
As it turns out, gravitational capture events, like the one we are experiencing right now, are more common than we think, especially since the Arjuna asteroid belt is close to Earth.
Some Arjuna asteroid belt objects can approach Earth at a close range of around 2.8 million miles (4.5 million kilometers), a fraction of their distance from the Sun.
Furthermore, this isn’t the first time the Earth has accidentally captured an asteroid. Previous documented cases include ones that lasted up to a week and two others that took place over a much more extended period of time.
Appropriately enough, the official term for this category of objects is, in fact, “mini-moons.” One documented case occurred in 2020 and turned out to be a rocket booster from the 1960s. More specifically, it was from the 1966 Surveyor 2 Centaur launch.
The latest “mini-moon” before 2024 PT5 was 2022 YG, another asteroid that accidentally got within the Earth’s capture range. In 1981 and 2022, we also saw 2022 NX1, scheduled to return for a visit in 2051.
Unfortunately, 2024 PT5 will not be observable by the naked eye, but professional astronomers should have access to the equipment necessary for photo documentation of the asteroid.
Any telescope that is 30 inches (7.62 centimeters) in diameter and has the required extra equipment in addition to that should be sufficient.
Since it’s estimated to be approximately 37 feet (11.28 meters) wide, the moon is a whopping 308,108 times wider than the lunar pretender asteroid 2024 PT5!
The asteroid was found by a group called ATLAS, which stands for Asteroid Terrestrial-impact Last Alert System, and they published their findings in Research Notes of the AAS, which is a non-peer-reviewed, indexed, and secure record of works in progress, comments and clarifications, null results, or timely reports of observations in astronomy and astrophysics.
Their article is in volume eight, number nine, titled A Two-month Mini-moon: 2024 PT5 Captured by Earth from September to November. Carlos de la Fuente Marcos and Raúl de la Fuente Marcos from Universidad Complutense de Madrid in Spain are listed as the authors.
The article is open access, so it’s available to faculty, students, or public members who want to read it and learn more about 2024 PT5. The article is short compared to many other scholarly articles, so it’s a short read if you understand the relevant terms and equations.
It seems as if everyone is excited about this unique phenomenon, and the hype has even spread to Google. When you search for “mini-moon 2024,” a small illustration of the moon and 2024 PT5 will drift across your screen. If you click on it, you will be directed to the news section about 2024 PT5.
