Alejandro Rojas, spokesman for the Scientific Coalition for Ufology (SCU), said being unexplained did not mean the UFOs were alien.
He said: “Remember, the ‘U’ is for unidentified, not alien.
“We don’t know what these things are.
“Just because we get uncomfortable with the idea of aliens does not mean we should not investigate when the people who pilot our most advanced technology say they encounter something that outclasses their aircraft. It would be highly negligent not to investigate.”
Steven Aftergood of the Project on Government Secrecy at the Federation of American Scientists in Washington, DC, also urged caution.
He said: “It is somewhat dismaying to see how quickly ‘unidentified’ aerial phenomena are publicly interpreted and portrayed as UFOs of possibly extraterrestrial origin.
“Collectively, we should all be becoming more intelligent and more perceptive, not more stupid and gullible.”