Record Collapse of Earth's Upper Atmosphere Puzzles Scientists

An upper layer of Earth's atmosphere recently collapsed in an unexpectedly large contraction, the sheer size of which has scientists scratching their heads, NASA announced Thursday.

The layer of gas – called the thermosphere – is now rebounding again. This type of collapse is not rare, but its magnitude shocked scientists.

"This is the biggest contraction of the thermosphere in at least 43 years," said John Emmert of the Naval Research Lab, lead author of a paper announcing the finding in the June 19 issue of the journal Geophysical Research Letters. "It's a Space Age record."

http://www.space.com/scienceastronomy/puzzling-collapse-earth-atmosphere-100715.html