Cloud MountainA tower of water vapor makes a cumulonimbus cloud over Colombia look like a cotton-candy mountain in a picture taken last week by an astronaut aboard the International Space Station.Seen from 220 miles (354 kilometers) above Earth, the cloud might appear serene. But tall, dense cumulonimbus clouds are most often associated with thunderstorms and other severe weather events. (See more cloud pictures.)
Photograph courtesy NASA

Space Pictures This Week: Towering Cloud, Moon Geysers

A thundercloud aims high, stars are born near a galactic void, a Saturn moon spews ice, and more in the week's best space pictures.

Published December 4, 2010