A Puzzling Collapse of Earth's Upper Atmosphere   NASA - July 15, 2010

NASA-funded researchers are monitoring a big event in our planet's atmosphere. High above Earth's surface where the atmosphere meets space, a rarefied layer of gas called the thermosphere recently collapsed and now is rebounding again.

This is the biggest contraction of the thermosphere in at least 43 years. It's a Space Age record. The collapse happened during the deep solar minimum of 2008-2009 - a fact which comes as little surprise to researchers. The thermosphere always cools and contracts when solar activity is low. In this case, however, the magnitude of the collapse was two to three times greater than low solar activity could explain. Something is going on that we do not understand.