On September 29, 2024, a small asteroid temporarily entered our planet’s orbit, capturing the attention of many astronomy enthusiasts. First spotted on August 7, scientists officially named the asteroid “2024 PT5.” However, it is often referred to as a “mini-moon,” a term used to describe non-Earth objects that enter Earth’s orbit and complete full revolutions around the planet. 2024 PT5 is known to have originated from the Arjuna asteroid belt, which revolves around the Sun close to our planet and contains rocks that follow a similar orbit to Earth. Just like this, some small asteroids seldom get relatively close to Earth’s orbit. According to Northeastern University’s news site Northeastern Global News, if an asteroid is moving closely at a relatively slow speed, Earth’s gravitational pull can have a strong influence, potentially trapping it in orbit temporarily.
Although this seems like a once-in-a-lifetime occurrence, it is far from the first time that a “mini-moon” has appeared in Earth’s orbit. The last time that one was seen was in 2022, which was itself a repeat visit from the same asteroid that appeared before as a mini-moon in 1981. While most are harmless, some asteroids cause immense amounts of damage. According to an article written by NASA (National Aeronautics and Space Administration), a particular asteroid in 2013 entered the atmosphere in Chelyabinsk, Russia at around 11 miles per second and exploded 14 miles above ground, releasing energy equivalent to around 30 times the atomic bomb dropped on Hiroshima, Japan, resulting in 1,600 casualties. Do not fret, though, because the 2024 PT5 is predicted to float around until it leaves Earth’s orbit, without causing any harm.
While 2024 PT5 is too small and dim to be seen with the naked eye, with its diameter a mere 37 feet, which is around the size of a bus, it can be spotted fairly well with a professional telescope. If you are planning to take a look at it, do so before the asteroid leaves Earth’s orbit on November 25, which will occur 56.6 days after entering Earth’s orbit. If you missed it already, though, do not worry—scientists predict that the same 2024 PT5 will come back in 2055, when the paths of the asteroid belt and Earth align and put it back into our orbit.