Starting next week, the moon, Earth’s closest celestial body, will be joined by a new neighbor: a second moon. From Sept. 29 until Nov. 25, astronomers calculate that 2024 PT5— which is what scientists think is an asteroid but have dubbed a “mini-moon”—will be looping around Earth.

It won't be there forever, but Earth will have a second moon when a small asteroid begins to orbit the planet later this month, space researchers have announced.

Scientists aren't sure if 2024 PT5 is an asteroid. At roughly 10 meters in length, 2024 PT5 is difficult to spot without a telescope. Yet a new study reveals that for the next two months, 2024 PT5 will join our Moon in orbit around our planet, which means Earth will (temporarily) have a second moon, from September 29 to November 25.