I'm pretty sure that's diffracted di-hydrogen oxide.
Well I went up to SR 528 / Rt. 1 area and pulled over at the Banana River, along w/maybe 20 other cars or so. Got there 9am with my wife who's not a space-nut but I got her to come. Radio said they'd come in over Ft. Myers just a couple minutes ago.. I'm looking in the sky, looking, looking.. nothing. Wife says "What's that up there - just an airplane or something?" Of course it was Atlantis!! I could see easily now w/the naked eye but w/binoculars it was awesome - shortly the twin sonic booms rocked the area pretty good.. these two older guys were staring in the wrong area so I ran over and said "there! there!!" and pointed.. they said "No that's not it, that's much too high for the shuttle..." (oh well, just trying to be helpful!) We could follow it for the next 3 minutes or so until it made it's turn around the HAC and lined up,.. never saw it again although tried of course - not sure I was looking in right place for final approach and besides it was far away then - if they'd landed on 33 like originally said, it would've been a great place to watch them turn around the HAC and line up.. oh well.
When we left there were STILL people staring at the sky searching for it LOL
came home and yelled at my TiVO for not recording the landing like I asked it too.. oh well always great to see one in the sky