Electric-blue clouds appear over Antarctica, Earlier Than Normal

Scientists watch Noctilucent clouds (earth's highest) that return to Antarctica Nov. - Feb. The clouds are over the Arctic during the northern hemisphere summer.  Because the clouds returned early, they think it may be a sign of climate change.   When I was in Antarctica in February 2012,  I saw only thick, white cloud cover.  http://bit.ly/198DigL

Image comment: NASA AIM satellite image of Antarctica
Image credits: LASP / University of Colorado