Cor - looks lovely, doesn't it? Even if it's not the actual Aurora themselves (see earlier post)

I'm intrigued... you said you 'applied polar coordinates' - please explain how... I've obviously missed this feature of GE, and I could really do with that knowledge!

Second - you mentioned the black areas. Alas, this is a BIG problem - to remove them, the images would have to be fetched by a separate server, and then processed to turn all the black pixels into transparent ones, and then the image would need to be 're-served' back to end-users.

Alas, that puts rather a load on whichever developer creates the final KML - because they become the bottleneck where all GE users are fetching their images from. Chances are, they'll have a lot less bandwidth than NOAA, unfortunately.

Perhaps Google/Keyhole can apply the necessary pressure to NOAA (as they have with NASA) to get the black turned into transparency at source? It wouldn't affect the images that NOAA create on their own site, and would make them perfectly suitable for GE.

Here's hoping. Again - great idea. Just the sort of thing that would make GE even more stunning! Keep pushing!