Two Chilean volcanic mountain peaks in the South Pacific left these giant chicken tracks in the clouds in this image captured by NASA's Aqua satellite on April 29. Meteorologists call this cloud pattern "ship-wave-shape" because they look like boats' wakes; but in a way they're actually mountains' wakes. When air blows over and around mountain peaks, it rises and falls in ripples with peaks and troughs. Wherever the air rises, it cools and forms clouds. In places where the air falls it warms, dissipating cloud vapors and leaving behind clear spaces.
The ship-wave-shape cloud on the left was induced by the island of Alejandro Selkirk, which has an elevation of 1,330 meters. The one on the right was induced by Robinson Crusoe Island, elevation 915 meters. The islands are so high that they often create atmospheric patterns that can be seen from space, according to NASA.