(NewsNation) — A bipartisan group of lawmakers continued their push Wednesday to solve concerns surrounding the decades-old UFO mystery.

The Senate Armed Services Subcommittee on Emerging Threats and Capabilities held the second hearing on the phenomenon in more than 50 years.

Dr. Sean M. Kirkpatrick, director of the All-domain Anomaly Resolution Office (AARO), was the sole witness for the hearing. Lawmakers asked about administrative matters, including ensuring that AARO has the necessary funding to execute its scientific mission.

“I also state clearly for the record that in our research, AARO has found no credible evidence thus far of extraterrestrial activity, off-world technology or objects that defy the known law of physics,” Kirkpatrick said in his testimony.

He added: “If the significant scientific data were ever attained that a UAP encounter can only be explained by extraterrestrial origin, we are committed to working with our interagency partners at NASA to appropriately inform U.S. government leadership of its findings.”

Kirkpatrick co-authored a draft paper last month with Harvard University professor Avi Loeb that will likely prompt questions from lawmakers. The paper theorizes that recent unidentified aerial phenomena, or UAPs, the U.S. Department of Defense is studying could be “extraterrestrial technological probes” sent from a “parent craft.”

In May 2022, the House Intelligence Subcommittee held its first congressional hearing on UFOs in nearly 50 years, just months after the Pentagon promised it would investigate UFO sightings more seriously.

All of that came after The New York Times published cockpit footage from a Navy pilot who encountered a UFO, or unidentified aerial phenomenon as they are formally called, in the air. The Pentagon then said it would make more UAP footage public.

Briefings from naval aviators who witnessed the mysterious objects have subsequently paved the way for groundbreaking UAP-related legislation.

The DOD created the AARO to scientifically analyze UFOs “that exceed the known state of the art in science or technology.” To cut through several layers of bureaucracy, lawmakers mandated that AARO’s director report to top Pentagon and intelligence community leadership.

The government has still not released any findings as to what the objects were, or if they have any information or hunch at all that the objects may have origins outside Earth.

The Hill contributed to this report.