Known as “2020 CD3” and only discovered in February, Earth’s temporary mini-moon has left orbit and is headed for the Sun. According to astronomers’ calculations, the car-sized object—likely an asteroid or lunar rock—had been circling Earth for at least a year. 2020 CD3 likely departed on March 7, astronomy-software developer Bill Gray tells The Atlantic’s Marina Koren. It might return in 2044.