(The Hill) — NASA said a rocket of unknown national origin that crashed into the moon earlier this year produced a double crater on the surface, an unexpected feat.

The agency’s Lunar Reconnaissance Orbiter, which collects data on the moon, spotted two craters after the “mystery rocket body” collided with the moon on March 4, NASA said recently.

It created an eastern crater about 19.5 yards in diameter and a western crater about 17.5 yards in diameter. 

The agency said the double crater might indicate that the rocket had a large mass on each end of it. A rocket that has used up its fuel usually will just have its mass on the end with the motor, with the other side being an empty fuel tank. 

The rocket’s origin is uncertain, but the double crater that it produced might reveal its identity, according to the release. 

A rocket body hitting the moon has not created a double crater before, the release states. 

The Houston Chronicle reported Thursday that no space-exploring country has claimed the rocket as their own so far.