On June 12, 2009, Russia's Sarychev Volcano exploded in outstanding fashion, delivering clouds of ash upward in an extraordinary display of geophysical force. It was the first time Sarychev had erupted in over twenty years and it occurred, just as the International Space Station was soaring above.
There's a lot happening in this brief sequence. The rising cloud casts a black shadow on the lands below. Dark ash, like a pyroclastic flow, can be seen racing down the inclines of Sarychev's summit. The plane, milky cloud located over the largest ash-plume, uncannily white given the circumstances, is called a "pileus cloud," and is believed to form briefly as the air above the ash pole rises and chills.