COLORADO SPRINGS, Colorado (CNN) -- Fighter jets scrambled in an unsuccessful attempt to investigate a contrail of unknown origin first seen over the Caribbean and later reported over the midwestern United States, the Department of Defense said Thursday.
The North American Aerospace Defense Command scrambled the jets soon after unverified reports were received around 4 p.m. Wednesday that the contrail, seen near the Turks and Caicos Islands, was headed northwest toward the United States, said Lt. Cmdr. Curtis Jenkins, a spokesman for the Colorado Springs-based group.
A contrail is a white trail of condensed water vapor that sometimes forms in the wake of an aircraft.
The jets were scrambled from more than one base and more than one location, he said, though he did not know how many jets or from how many locations.
Commercial airline pilots later reported the contrail over Florida and then over Indiana, after which no more sightings were reported, he said.
The jets attempted to intercept and identify the source of the contrail, but no visual or confirmed radar contact was made, he added.
"I don't know that anybody was predisposed to think it might be some thing or the other," he said. "We don't even know that it was a thing. It was just simply reports of contrails. We don't even know that it was the same one. We had reports from different places and NORAD did its job and tried to find out."
NORAD is coordinating with the Federal Aviation Administration and is continuing to investigate the reports, he added.