Several pilots told the New York Times in an article published in May about multiple encounters with UFOs with no visible engine or infrared exhaust plumes.
In April, the Navy introduced guidelines for its pilots to report unexplainable events so the military can keep track of what may, or may not, be happening. Politico first reported on this matter.
A Navy official told CNN at the time that the Navy does not believe aliens have been flying around US airspace.
But there have been “a number of reports of unauthorized and/or unidentified aircraft entering various military-controlled ranges and designated air space in recent years,” the Navy said in a statement.
The Navy said these kinds of “incursions” pose both a security risk and safety hazard.
“For safety and security concerns, the Navy and the USAF takes these reports very seriously and investigates each and every report,” the statement said.

This content was originally published here.