An asteroid that’s projected to get locked into orbit as a mini moon next month may actually be space junk from a failed 1966 moon lander mission.

The asteroid, dubbed 2020 SO, was first identified in September, according to the International Astronomical Union. It was identified by a telescope in Hawaii that was searching for potential “doomsday rocks,” according to the Associated Press. Scientists expect that it will join the ever-growing field of space junk in a temporary orbit around the Earth next month.