PASADENA, Calif. (AP) — Space enthusiasts have been abuzz for days over whether the Mars rover Curiosity captured an extraterrestrial crash. On Friday, NASA declared the mystery solved.

Seconds after the car-size rover parked its six wheels in an ancient crater, a tiny camera under the chassis snapped a picture revealing a smudge on the horizon. The feature disappeared in a later photo.

Was it dirt on the camera lens or a spinning dust devil? It turned out Curiosity spotted the aftermath of its rocket-powered backpack crash-landing in the distance.