(KXAN) — Earth is picking up a new moon later this week. This mini-moon is about 33 feet across, the size of a small school bus, and will orbit the Earth from Sept. 29 to Nov. 25. This animation shows a rough outline of the orbital path of the mini moon. Graphic not to scale. (Credit: Eric Henrikson/KXAN News) "We don't know how often (this mini-moon orbits the Earth), because this guy is pretty faint, and then similar ones would be pretty faint," said Anita Cochran, senior research scientist with the University of Texas' McDonald Observatory. The mini-moon, nicknamed 2024 PT5, will orbit the Earth in a horseshoe pattern before the gravity of other objects in our solar system pull it off. It will return to orbit the Earth again in 2055. "It's a tug of war, and the tug of war is won by the Earth for a short period of time, in this case, but not for a very long period of time," Cochran said about our brief time with the mini-moon. What is a mini-moon? While quite small, the rock gains the classification of a mini-moon once it orbits the Earth. Likely originating from the asteroid belt, we know little else about the rock. The mini moon, spotted by the ATLAS project in South America, circled in green. COURTESY: Kacper Wierzchos | @WierzchosKacper Planets gain moons in a couple of ways. A planet's gravity can capture a rock passing by it in space. If the rock is big enough and close enough, it can gain a semi-permanent orbit around the planet. "If it gets captured in orbit, there was nothing else to change it, it would stay in order around the Earth. But the problem is, as far as this is concerned, is that there is other things to attract it," Cochran said. The other way a planet gains a moon is through a collision. Our moon was created when a planet the size of Mars collided with the Earth about four billion years ago. Spotting the mini-moon Unfortunately, we won't be able to easily spot the mini-moon due to its size. At just 33 feet across, it is already hard to see in the vast expanse of space. Its orbit will be pretty far away too. It will orbit the Earth at a distance five times that of the distance between the Earth and the Moon. The NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS) spotted the rock as it hurtled toward the Earth. ATLAS checks the sky daily for large rocks that could possibly impact the Earth. This mini-moon won't hit us. Cochran said spotting mini-moons, even with advanced technology, is challenging. "They don't really get very close to the Earth. And therefore, unless you're looking at the right spot, you don't pick them up," Cochran said.