Image submitted by Gordan Ugarković, Zagreb, Croatia, 6 September 2008.
Gordan writes:
"Attached to this mail you can find an animation taken from frames taken on August 29th showing a rather large, circular cloud that emerged from the terminator and dissipated within a short period afterwards. The 10 images composing the animation are the more heavily exposed frames, which were cropped and aligned on the curious feature. The color comes from my quick'n'rudimentary debayer tool and the images were further processed in Photoshop. Also attached is a single crop enlarged 3x which I used to guesstimate the cloud height at an excess of 100 km."