This photograph shows how clouds can hang at a precise altitude. Volcanic peaks on the Galapagos Islands rise above the cloud layer. The circular volcanic summits visible in the picture highlight both the classic conical shape of the volcanic structures and the stability of the cloud altitude. The radiating fan pattern in the cloud around the volcanos is caused by downslope winds. The equatorial location of the islands contributes to the uniformity of the cloud radiation around the volcano summits. Similar phenomena have been seen in the martian atmosphere, and scientists are keenly evaluating this atmospheric comparison.
STS 51-G, June 1985. Picture #25-32-061.