Secret to Pulsating Auroras Revealed!

magnetosphere, however. These particles are stored on the night side of the magnetosphere until a substorm releases their energy. Then they speed into earth’s upper atmosphere creating the beautiful, shimmering ribbons of light we call the Northern and Southern Lights (Aurora Borealis and Aurora Australis).

 

But until recently scientists have not known for sure what causes pulsating auroras. These green, red, and purple auroras occur much higher in the atmosphere and flash or pulsate their colors.

 

As some scientists suspected, a pulsating aurora is created when a whistler mode chorus wave (a wave loaded with charged particles which makes a chirping sound) enters the magnetosphere and sends electrons raining down into the earth’s atmosphere.

This phenomenon was uncovered by NASA’s Time History of Events and Macroscale Interactions during Substorms (THEMIS) 

mission and Japan’s Exploration of Energization and Radiation in Geospace (ERG) satelite.

 

By making and comparing observations from ground-based cameras of the THEMIS mission and from the sky with the ERG satellite, scientists were able to see this phenomenon occur from start to finish.