As part of the Apollo 16 mission in 1972, the rocket’s Saturn V third booster SIVB was intentionally crashed into the surface of the Moon after it had propelled the crew into lunar orbit. Somewhere along its descent, NASA scientists lost track of it and its location has remained a mystery ever since.

The 17.7-meter (58-foot) SIVB booster contained liquid hydrogen, liquid oxygen tanks and a J2 engine. While smashing it into the Moon might sound like reckless space littering, the crash was intended to measure seismic activity in the hope of learning more about its surface.

Forty-three years later, the crash site has finally been found by Jeff Plescia , a physicist and geologist from Johns Hopkins University, Baltimore. He found the lunar scar through high-resolution images from the NASA Lunar Reconnaissance Orbiter.

“I did finally find the Apollo 16 SIVB crater,” Plescia told Inside Outer Space . “It looks like the others, but its position was much more poorly defined since the tracking was lost prior to impact.”