Watch Live: Congress to hold first public hearing on UFOs in 50 years, probe possible national security threat

House Intelligence subcommittee Tuesday is holding the first congressional hearing on UFOs in 50 years, as building evidence on the sightings raises more questions than answers.

“There are a lot of unexplained aerial phenomena. We don’t know what they are, and they can’t be easily rationalized as weather phenomenon or balloons or anything else. So it’s quite a mystery,” House Intelligence Committee Chairman Adam Schiff, D-Calif., said of the hearing.

“We’re going to press them on some very serious issues,” Rep. Andre Carson, D-Ind., who chairs the House Intelligence Counterterrorism, Counterintelligence, and Counterproliferation Subcommittee, added.

Carson said in a statement announcing the hearing that it’s crucial for the government to “seriously evaluate and respond to any potential national security risks – especially those we do not fully understand.”

The hearing on what the U.S. government officially calls “Unidentified Aerial Phenomena” (UAP), begins at 9 a.m. ET. It comes after years of unexplained sightings, primarily by U.S. military personnel, of flying objects, which often had no “discernable” propulsion systems and unusual “movement patterns.”

Carson said in a statement announcing the hearing that it’s crucial for the government to “seriously evaluate and respond to any potential national security risks – especially those we do not fully understand.”

The hearing on what the U.S. government officially calls “Unidentified Aerial Phenomena” (UAP), begins at 9 a.m. ET. It comes after years of unexplained sightings, primarily by U.S. military personnel, of flying objects, which often had no “discernable” propulsion systems and unusual “movement patterns.”

Under Secretary of Defense for Intelligence and Security Ronald Moultrie and Deputy Director of Naval Intelligence Scott Bray will testify at the hearing Tuesday. But it’s not clear how much they will be willing or able to share in the public forum.

“I think they will be comfortable telling the public what we do know, and what is still yet to be explained,” Schiff said when asked what people can expect from the hearing. “But they’ll be very careful not to speculate that this is some extraterrestrial or this is some foreign adversary with some… unknown technology. They will set up the limits of what we know what we don’t.”

The government has said that UAP “probably lack a single explanation.” Neither classified nor unclassified reports from the government so far rule out space aliens. But other possible explanations are “airborne clutter” like birds and balloons, “natural atmospheric phenomena,” like ice crystals, highly classified U.S. government programs, or “foreign adversary systems” from Russia, China or other countries.

“Let’s assume that it’s… another country, another nation or another group that’s operating something that we don’t fully understand,” Heritage Foundation senior fellow for naval warfare and advanced technology Brent Sadler told Fox News Digital. “That’s a definitely a security threat… that we can’t necessarily defend against because you can’t defend against something you don’t understand.”

“I think they will be comfortable telling the public what we do know, and what is still yet to be explained,” Schiff said when asked what people can expect from the hearing. “But they’ll be very careful not to speculate that this is some extraterrestrial or this is some foreign adversary with some… unknown technology. They will set up the limits of what we know what we don’t.”

The government has said that UAP “probably lack a single explanation.” Neither classified nor unclassified reports from the government so far rule out space aliens. But other possible explanations are “airborne clutter” like birds and balloons, “natural atmospheric phenomena,” like ice crystals, highly classified U.S. government programs, or “foreign adversary systems” from Russia, China or other countries.

“Let’s assume that it’s… another country, another nation or another group that’s operating something that we don’t fully understand,” Heritage Foundation senior fellow for naval warfare and advanced technology Brent Sadler told Fox News Digital. “That’s a definitely a security threat… that we can’t necessarily defend against because you can’t defend against something you don’t understand.”

Open C3 Subcommittee Hearing on Unidentified Aerial Phenomena – YouTube