Space.com has a great article and amazing series of photographs from the latest events when aurora display was triggered by a series of coronal mass ejections. Nature is so beautiful, glad we are able to observe it. 

‘Cannibal’ sun eruption gives departing astronauts their best aurora | Space:

The latest aurora display was triggered by a series of coronal mass ejections, bursts of magnetized plasma that the sun blasted out last week within a short period of time. The second outburst, travelling a bit faster than the first one, cannibalized its predecessor on the way, resulting in a much more powerful plasma cloud than originally expected.