Polar Clouds from Space Shuttle Exhaust.

The article focuses on a study about the formation of the polar mesospheric clouds (PMCs) and discusses its scientific impact. There are disputes regarding the formation of PMCs. Some researches indicate that they became brighter and more frequent in the late 20th century. A few scientists also suggest that they are indicators of the global climate change. It was found that a shuttle exhaust plume (STS-107) can also create polar clouds, contributing to 10-20% of the total ice content of PMCs.