This spectacular light show took place over Santiago on the night of December 18. What was it? Certainly not an aircraft. However, it could have been a fleet of balloons carrying flickering LED lights. Once, it would have been hard to generate enough luminosity from lightweight devices to create such a light show at this level, but that is no longer true. Still, this is a possible unknown.

http://www.youtube.com/watch?v=LrssYOEeGT4
Story Source:
http://www.youtube.com/watch?v=LrssYOEeGT4