On Sunday, Sept. 29, Earth captured a new "minimoon" called 2024 PT5. The bus-size asteroid is expected to orbit our planet for 57 days, but is too small to be visible to amateur skywatchers.

The Earth has got itself a new moon.The new satellite is temporary: it will leave again at the end of November. And it is very small, at just 10 metres across.But it is one of a very few times that we have seen the Earth acquire a new temporary satellite of this kind.

Scientists call such phenomena mini-moons. The asteroid was found by a group called ATLAS, which stands for Asteroid Terrestrial-impact Last Alert System, in August. The researchers who found it published a nonpeer-reviewed study about the asteroid.