Tried exporting video clips from Celestia. Running it on secondary display at 1920x1080, tried exporting at 1280x720 with Xvid codec and as uncompressed avi. The Xvid codec version seemed to be better, more quality rendering, at around 11 fps. The look on the dome of course would be the final test. The idea is to warp the exported video after cropping it to a square shape and see if lower third centre view would be good for globes and such.