I was lucky enough to see the Northern Lights en route from SFO to LHR from the flight beck of a VS 747.

(September '95 - on board G-VJFK "Boston Belle")

I was visiting the flight deck & the crew pointed out the Northern Lights & then dimmed the lighting on the flight deck so we could better outside.

We sat there for a good 15 / 20 mins chatting about flying while watching the wonderful display outside. Majorly cool