A high altitude balloon lofting an instrument payload for the observation of cosmic X-ray sources floats over Arizona. The six tubes hanging down from the balloon are vent-tubes, through which excess helium vents to the air.

On May 18, 2009 - and again on June 11 of that same year - a similar 4000 pound NASA weather balloon, that was released from the Columbia Scientific Balloon Facility at Fort Sumner, New Mexico, sparked a number of UFO reports when it drifted over Arizona.

[Image borrowed from www.aerostar.com.]