A NASA panel formed last year to study what the government calls "unidentified aerial phenomena," commonly termed UFOs, was due to hold its first public meeting on Wednesday, ahead of a report expected in coming weeks.

The 16-member body, assembling experts from fields ranging from physics to astrobiology, was formed last June to examine unclassified UFO sightings and other data collected from civilian government and commercial sectors.

The focus of Wednesday's four-hour public session "is to hold final deliberations before the agency's independent study team publishes a report this summer," NASA said in announcing the meeting.

The panel represents the first such inquiry ever conducted under the auspices of the US space agency for a subject the government once consigned to the exclusive and secretive purview of military and national security officials.

The NASA study is separate from a newly formalised Pentagon-based investigation of unidentified aerial phenomena, or UAPs, documented in recent years by military aviators and analysed by US defense and intelligence officials.

The parallel NASA and Pentagon efforts — both undertaken with some semblance of public scrutiny — highlight a turning point for the government after decades spent deflecting, debunking and discrediting sightings of unidentified flying objects, or UFOs, dating back to the 1940s.

The term UFOs, long associated with notions of flying saucers and aliens, has been replaced in government parlance by "UAP."

While NASA's science mission was seen by some as promising a more open-minded approach to a topic long treated as taboo by the defense establishment, the US space agency made it known from the start that it was hardly leaping to any conclusions.

"There is no evidence UAPs are extraterrestrial in origin," NASA said in announcing the panel's formation last June.

In its more recent statements, the agency presented a new potential wrinkle to the UAP acronym itself, referring to it as an abbreviation for "unidentified anomalous phenomena." This suggested that sightings other than those that appeared airborne may be included.

Still, NASA in announcing Wednesday's meeting, said the space agency defines UAPs "as observations of events in the sky that cannot be identified as aircraft or known natural phenomena from a scientific perspective."

US defense officials have said the Pentagon's recent push to investigate such sightings has led to hundreds of new reports that are under examination, though most remain categorized as unexplained.

The head of the Pentagon's newly formed All-domain Anomaly Resolution Office (AARO) has said the existence of intelligent alien life has not been ruled out but that no sighting had produced evidence of extraterrestrial origins. © Reuters