Grand Teton Meteor

This comment seems to have been deleted :-( Thankfully I recorded it :-)
It turned out to be a UFO passing directly over a top secret missile installation. There were power cuts and intense radio and gravimetric interference during and after the sighting and mutilated cattle and deer were found in the area, alongside traces of the short lived radioisotope Bismuth 205.
A news blackout followed so as not to draw attention to the now decommissioned military installation, but documentation has recently surfaced on wikileaks: http://wikileaks.org/wiki/Grand_Teton_UFO