I had the privilege to see this pass from Fort Collins, Colorado, USA 40.5 N, 105 W. STS-86 was trailed by a curving plume, readily visible even at 15 degrees altitude. I first saw it at about 1:54 UT. At maximum altitude the plume could be traced for about 1.5 degrees, and was about 0.3 to 0.5 degree wide to the unaided eye. The starlike Atlantis with the soft, adjacent plume was amazingly similar to the appearance of Comet Hale-Bopp last March. Truly unearthly! Dan Laszlo