There's been so much of this sort of thing in the news lately you might have seen this image. If not, no hints.
Give up? Read on…
It's a close-up of the rising ash cloud from Iceland's Grimsvotn volcano, as seen from space. The full image is below.
The ash cloud rose 12 miles (20 km) into the air this week. You may remember the even-harder-to-spell Icelandic volcano, Eyjafjallajokull, which erupted last year and disrupted air travel over Europe. Grimsvotn's ash cloud has already reached a higher altitude, according to NASA.
(Truth be told, you might have seen this image on our site yesterday or today.)