The European Space Agency’s experimental Proba-1 Earth-observing satellite pinpointed the source of volcanic ash that paralyzed air traffic across Europe in mid-April.

A 5-meter-resolution black and white image recorded April 20 by Proba-1’s High Resolution Camera depicts the ash cloud rising from Iceland’s Eyjafjallajökull glacier. A second image, taken the day before, shows the breach in the glacier made by the volcanic eruption.

Launched in 2001, Proba-1 was the first in the European Space Agency’s series of microsatellites aimed at providing in-orbit testing of new space technologies.