I guess it has been solved now. However
Originally Posted by Pie™
There was a spiral of light in the sky, expanding like some kind of green laser.
Now, in my town we see the Aurora Borealis every winter, so green lights in the sky is not a new phenomenon. Never the less, in my 20 years here I've never seen anything like this, and for a second I thought it looked like a huge explosion in the distance.
I thought it might have been a specular phenomena of the upper atmosphere using a high power argon/krypton laser. Be it malfunction of communicaitons/scan or perhaps someone cloud-writing/experimenting.
Aurora Borealis was a close second in my guess.
But I guess not afterall. :'( Still must've been pretty nice to behold in person.