These cloud formations were seen over the western Aleutian Islands. Their color variations are probably due to differences in temperature and in the size of water droplets that make up the clouds.This image was acquired by <a href="http://landsat7.usgs.gov/">Landsat 7’s</a> Enhanced Thematic Mapper plus (ETM+) sensor on June 16, 2000. Sensor: Landsat 7/ETM+. Data Start Date: 6/16/00.