A five-ton mystery rocket was set to crash into the moon at 6,000 mph Friday, and NASA will promptly move its orbiting camera into position to study the fallout.

The projectile is a spent rocket booster believed to be either from a SpaceX rocket launched in 2015 or a Chinese rocket launched a year earlier, though both parties deny ownership. Those rockets were discarded into space after launching satellites. The one on a collision course with the moon is an upper-stage booster that is 40 feet long and weighs 10,000 pounds.