At http://cosmictusk.com there is a report, published by the Royal Society, that says that some 4 years ago green fireballs streaked across the sky over Australia which led to a succession of UFO reports. However, it is now thought they might have been meteors or ball lightning caused by electrically charged shockwaves in a similar fashion to the way aurorae is created. The colour was predominantly green, an interesting observation in itself, as the colour green is associated with myth and the gods and green stone such as jade was highly prized, especially as a medium to make stone axes. The axe, as a common symbol in the ancient world, is generally associated with lightning – or meteors. The timing suggests the event was triggered by debris from Comet 73P/Schwassman-Wachmann3 and a transient electrical link between the ionosphere and the ground, producing the ball lightning effect. As the comet in question was many miles distant from the earth one is left wondering what might happen if a comet came much closer … and if something like that might have happened in the past.
A post on the next day makes the point that the comet has a 5.4 year periodicity and is due to return in November 2011 which means the theory can be tested – will it produce further cosmic green magic.
At the same web site and under the title, Great Serpents: Comets by another name, there is a piece taken from www.angelfire.com/nt/dragon9/SERPENT.shtm (which I have not checked out) that claims that Native American lore about a Great Serpent was associated with a flood tradition resembling that of Noah. In one tale the serpent lived at the bottom of a lake somewhere in the NE of N America, a situation reminiscent of the Anglo-Saxon Tale of Beowulf where the Grendel hides.