The United States Congress on Tuesday held its first hearing in half a century on the issue of unidentified flying objects (UFOs). There is still no confirmation of extraterrestrial life from the government.

Testifying before a House Intelligence Subcommittee, Pentagon officials said nothing new about the ongoing investigation into hundreds of unexplained apparitions in the sky. They revealed, however, that they have chosen the director of the working group who will coordinate the collection of data on what the government calls “unidentified aerial phenomena”.

Undersecretary of Defense for Intelligence Ronald Moultrie added that the Pentagon is also trying to “de-stigmatize” and encourage pilots and other military personnel to report anything unusual they see. “We want to know what’s there just as much as you want to know what’s there,” Moultrie told lawmakers, adding that he is a science fiction fan. You are not the only ones asking us questions. Our loved ones ask us too, all the time.

Lawmakers from both parties say UFOs are a national security concern. Apparently, unpowered aircraft have been sighted near military bases and along coastlines, and some worry that witnesses may have spotted secret Russian or Chinese technology.

But these appearances are usually ephemeral. Some are seen for only a moment on camera ― then the image is often distorted by the lens. The US government may have other technical information about this that has not been made public.

An interim report released last year by intelligence officials listed 144 sightings of aircraft and other devices flying at mysterious paths or speeds. In all but one of the cases examined, there was insufficient information for investigators to describe, even in a very general way, the nature of the incident.

A senior Pentagon executive on Tuesday illustrated the complexity of the task. Deputy Director of Naval Intelligence Scott Bray presented a short video shot by an F-18 fighter. The tape shows a blue sky and some clouds. In a single image (which took us several minutes to find) we see something that looks like a balloon.

“As you can see, finding [unidentified aerial phenomena] is harder than you might think,” he said.

Two members of the committee urged officials to make every effort to elucidate these incidents, recalling again the threat they pose to the security of the United States.