PHOENIX -- A silver object spotted floating over metro Phoenix on Monday evening has been identified.
Authorities said it was a research balloon from the Columbia Scientific Balloon Facility in New Mexico, not a UFO.
The NASA-contracted facility launched the 2-ton, teardrop-shaped balloon Monday morning from Fort Sumner, north of Roswell.
On the balloon payload were university student's devices, including one to collect air samples.
The devices were launched on the balloon to test how they work at high altitudes.
The Arizona Republic reported the balloon drifted west from New Mexico at 45 mph and reached a height of 120,000 feet above sea level. It landed west of Phoenix early Tuesday.