EBEX flight causes UFO reports

AZ Balloon (Stratocat) Stratospheric balloon. June 11, 09 Fort Sumner, New Mexico.- More like a rocket than a balloon, the maiden flight of the EBEX instrument ended tonight at 21:40 local time, a few kilometers northeast from Lake Havasu in the western side of Arizona, close to the border of California, in the southwestern of United States. The trip of more than 13 hours was the culmination of a project started at University of Minnesota's Physics and astronomy group a few years ago and of an integration and preparation effort at the launch base of more than two months. The balloon was launched from the Fort Sumner Airport in New Mexico, at 8:01 local time (14:01 UTC) and after a nominal ascent phase with a eastward flight path, it reached float altitude of near 117.000 ft and mounted onto the Jet Stream and following a very arrow-like straight course crossed the sky of New Mexico and Arizona.

... EBEX (acronym for E and B EXperiment) is a balloon-borne polarimeter designed to measure the intensity and polarization of the Cosmic Microwave Background (CMB) radiation, what in short is some kind of residual "noise" originated at the time of the explosion that created the Universe. Measurements of the polarization of the CMB could probe the expansion that took place shortly after the big bang helping to know values of several cosmological parameters as well to provide helpful information on the levels of polarized Galactic dust for future CMB observations. It is a result of a cooperative effort of the afored mentioned University of Minnesota, along with Brown, Pennsylvania, Harvard, McGill, UC Berkeley, The International School for Advanced Studies and University of Rome, La Sapiensa, Italy, Weizmann Institute of Science, Israel, Laboratoire Astroparticule et Cosmologie and Institut d'Astrophysique Spatiale from France, University of Wales - Cardiff and the University of Toronto in Canada. - stratocat

May be the cause of this sighting among others.