Red Aurora Over Southern Germany
October 26, 2011
Photographer: Roman Breisch
Summary Author: Roman Breisch; Jim Foster
The photo above showing a crimson-colored aurora was captured over southern Germany, between Munich and Augsburg, Germany, on September 26, 2011. It followed a M 7.1 class solar flare that happened two days earlier -- the time it takes for the solar wind to reach Earth. Auroras occur when high-speed particles from the Sun (the solar wind) blast the Earth’s magnetosphere. These energetic particles, primarily electrons, are guided along magnetic field lines where they typically collide with oxygen or nitrogen atoms. When these atoms recombine (in the case of oxygen, both atoms and molecules), light is emitted. WIth red auroras, there's no mixing of colors to dilute the red coloration, as is the case with green auroras. Although it's not precisely known how the red auroras are produced, aurora scientists believe that a huge influx of low energy electrons is involved. Note that long exposure times make these northern lights appear more noticeable than would be the case when observing with the unaided eye.
Photo details: Canon EOS 60D camera; 60 second exposure time; 1000 ISO; taken at 11:30 p.m. local time; camera is looking north.