> Did anybody capture good views of the 'ring of fire' effect

Here's one view -- better than the digital images
I snapped off my monitor. It's awesome --
http://forum.nasaspaceflight.com/forums/get-attachment.asp?action=view&attachmentid=15298

What is the physical basis for this luminescence?

I suspect it is impact illumination, as main engine
combustion products hit the thin atmosphere -- since the
ring collapses when the three mains shut down. The atomic
effect is O2 dissociating from impact energy, then recombining
and emitting a characteristic wavelength.

Don't forget the shuttle is only 55 miles up at engine
shutdown, coasting out to 135 miles or so half an orbit
later, when the OMS engines fire to circularize.

Thoughts?