US Navy pilots reported seeing UFOs (unidentified flying objects) traveling at hypersonic speed and performing impossible mid-air maneuvers off the east coast of the United States, The New York Times reported May 26, 2019.
Several pilots told the outlet that they saw the UFOs several times between 2014 and 2015, and reported the sightings to superiors.
UFO is a technical classification for anything in the air which is unexplained. The pilots did not claim the objects were extraterrestrial in origin. Many UFOs turn out to have logical explanations.
According to the Times:
"Navy pilots reported to their superiors that the objects had no visible engine or infrared exhaust plumes, but that they could reach 30,000 feet and hypersonic speeds."
The technical definition for "hypersonic speed" is any speed more than around 3,800 miles per hour, five times the speed of sound.
The pilots claimed the objects were able to accelerate then make sudden stops and instantaneous turns — maneuvers beyond the capacity of current aerospace technology.
"These things would be out there all day," Lt. Ryan Graves, an F/A-18 Super Hornet Navy pilot, who reported his sightings to the Pentagon and Congress, told the Times.
"Keeping an aircraft in the air requires a significant amount of energy. With the speeds we observed, 12 hours in the air is 11 hours longer than we'd expect."
No-one at the Defense Department interviewed by the Times is saying the objects are extraterrestrial in origin.
But the Pentagon is reportedly intrigued by the sightings of the objects, and recently updated its classified guidance for reporting sightings of UFOs.
Graves and four other pilots told the Times that they had seen the UFOs repeatedly between 2014 and 2015 while engaging in training maneuvers off the coasts of Virginia and Florida from the USS Theodore Roosevelt.
"There were a number of different reports," A Navy spokesman told the Times, remarking that in some cases "we don't know who's doing this, we don't have enough data to track this. So the intent of the message to the fleet is to provide updated guidance on reporting procedures for suspected intrusions into our airspace."
This article originally appeared on Insider. Follow @thisisinsider on Twitter.