I was suprised at how uneventful that seemed to go.
The 2-3 days while the planes were out of the skies, scientists were able to conduct a number of 'clear-skies' tests. (No contrails anywhere in the skies)
I also remember there being hardly any clouds in the sky for several days. The sky was that brilliant blue that only comes in early autumn.
Are you a member at Time Bomb 2000? Just curious...