The US space agency Nasa officially joined the search for unidentified flying objects (UFOs) on Thursday, but in keeping with the stigma associated with the subject, it refused to name the head of the new programme entrusted with doing so.
The official's appointment is the result of a year-long Nasa fact-finding report into what Nasa calls "unidentified anomalous phenomena (UAP)."
"At Nasa, it's in our DNA to explore -- and to ask why things are the way they are," Nasa chief Bill Nelson said.
An independent team of 16 researchers concluded in the report that the search for UAPs "demands a rigorous, evidence-based approach."
Nasa is well positioned to play a prominent role, thanks to its satellite capabilities and other technical assets. But the agency stressed in its report that any findings of possible extraterrestrial origin "must be the hypothesis of last resort -- the answer we turn to only after ruling out all other possibilities."
"We want to shift the conversation about UAP from sensationalism to science," Nelson said.
Even if Nasa has long explored the heavens, hunting for the origin, identity and purpose of a growing number of unexplained flying objects over planet Earth is bringing unprecedented challenges, AFP reported.
Military and civilian pilots keep offering a multitude of reports on strange sightings. But decades of movies and sci-fi books about aliens mean the entire topic is mostly laughed off by the public as the territory of cranks.
That atmosphere explained the unusual decision by Nasa to decline to identify the lead UAP official's identity.
"We need to ensure that the scientific process and methods are free," said Daniel Evans, who worked on the year-long Nasa report leading to the announcement.
"Some of the threats and the harassment have been beyond the pale quite frankly," Evans said.
Nasa released new report on UAPs on Thursday.
There's no proof aliens exist, but they might
The very last page of the report said "there is no reason to conclude" that extra-terrestrial sources are behind the hundreds of UAP sightings Nasa has investigated.
"However... those objects must have travelled through our solar system to get here," the report said.
Although the report did not conclude extra-terrestrial life exists, Nasa didn't deny the possibility of "potential unknown alien technology operating in Earth's atmosphere".
Limited amount of UAP data
Nicola Fox, the associate administrator for Nasa's Science Mission Directorate, said: "UAP are one of our planet's greatest mysteries" and that is mainly because of the lack of high quality data.
Despite numerous reported UAP sightings, Fox said there typically isn't enough data that "can be used to make definitive scientific conclusions about the nature and origin of UAP".
Fox announced that Nasa has appointed a new director of UAP research to "establish a robust database for the evaluation of future data".
The director will use AI and machine learning in the data gathering and analysis process, BBC reported.
Nasa recommends using AI tools
Artificial intelligence and machine learning are "essential tools" for identifying UAPs, the report said.
The public is also considered a "critical aspect of understanding UAP".
Nasa, which has said one of its biggest challenges of better understanding and identifying UAPs is a lack of data, aims to plug that gap through crowdsourcing techniques.
800 events
There have been more than 800 "events" collected over 27 years, of which two to five percent are thought to be possibly anomalous, the report's authors said during a May meeting.
These are defined as "anything that is not readily understandable by the operator or the sensor," or "something that is doing something weird," said team member Nadia Drake.
The US government has begun taking the issue of UAPs more seriously in recent years, in part due to concerns that they are related to foreign surveillance.
One example of a still unexplained phenomenon was a flying metallic orb spotted by an MQ-9 drone at an undisclosed location in the Middle East, which was shown to Congress in April.
Nasa's work, which relies on unclassified material, is separate from a parallel Pentagon investigation, though the two are coordinating on matters of how to apply scientific tools and methods.
In July, a former US intelligence officer made headlines when he told a congressional committee he "absolutely" believes the government is in possession of unidentified anomalous phenomena -- as well as remains of their alien operators.
"My testimony is based on information I've been given by individuals with a longstanding track record of legitimacy and service to this country -- many of whom also shared compelling evidence in the form of photography, official documentation and classified oral testimony," David Grusch told lawmakers.
Nasa weighs in on viral 'alien' photos from Mexico
Earlier this week, the alleged bodies of two "non-human" beings were presented during a congressional hearing in Mexico, generating a mixture of surprise, disbelief and ridicule on social media.
The purported mummified remains, which had a grayish color and a human-like body form, were brought by Jaime Maussan, a controversial Mexican journalist and researcher who reported finding them in Peru in 2017.