My friend and i were sitting on my dock and she asked what i thought that was ?I looked up to see something the size of a passenger jet that we see all the time leaving s,f airport heading east but this one to me reminded me of the space shuttle that i have seen before very high 20,000 feet or more i took out my monocular and spotted it and said it looks like the space shuttle i handed it to my friend and she said it just disappeared i said what turned back and it was gone i said well that was crazy we sat watching the area for 20 min looking if maybe it turned into the sun or someting but never saw it again. we are both star gazers and have seen many things in the night sky with telescopes and all 2nd time i have seen something starnge in the middle of the day