FLORIDA, USA - Nasa cannot yet explain all of the mysterious sightings that have been spotted in the sky, a major new report has said.

A panel assembled by the space agency to examine Unidentified Anomalous Phenomena, or UAPs, said that more and better data is required to be able to explain them.

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Recently, a number of people – primarily military pilots – have said they have spotted unrecognisable objects over the US. While some have been explained as having known natural or human-made causes, some continue to defy explanation.

Nasa’s chief, administrator Bill Nelson, said that the lack of good information had made it very difficult to explain those remaining examples.

“There is a global fascination with UAPs,” Mr Nelson said during a panel discussion following the publication of the report. “Much of that fascination is due to the unknown nature of it.

“Think about it: most UAP sightings result in very limited data. That makes it even more difficult to draw scientific conclusions about the nature of UAP.”

To better understand where those still mysterious phenomena are coming from, the space agency’s panel urged it to come up with “a rigorous, evidence-based, data-driven scientific framework” to better examine and understand them.

Some of that can be done by Nasa, it said, and the space agency should play a “prominent role”. But the research must be done across the US government.

Nicola Fox, the associate administrator of Nasa’s Science Mission Directorate, says begins the report by saying that UAPs are “one of our planet’s greatest mysteries”.

“Observations of objects in our skies that cannot be identified as balloons, aircraft, or natural known phenomena have been spotted worldwide, yet there are limited high-quality observations,” she writes. “The nature of science is to explore the unknown, and data is the language scientists use to discover our universe’s secrets.

“Despite numerous accounts and visuals, the absence of consistent, detailed, and curated observations means we do not presently have the body of data needed to make definitive, scientific conclusions about UAP.”

The report suggests that Nasa’s work is already helping with the mission to find out what is behind UAPs. It has done that in part just by launching its work to study them, which has helped to remove some of the stigma around talking about the phenomena.

The report notes that there is no firm evidence that the UAPs come from away from Earth. However, it notes that if that is the case, the spacecraft would have had to come from elsewhere in space – which means that Nasa should keep looking for that any other sign of alien life.

“At this point there is no reason to conclude that existing UAP reports have an extraterrestrial source. However, if we acknowledge that as one possibility, then those objects must have traveled through our solar system to get here,” the report says.

“Just as the galaxy does not stop at the outskirts of the solar system, the solar system also includes Earth and its environs. Thus, there is an intellectual continuum between extrasolar technosignatures, solar system SETI, and potential unknown alien technology operating in Earth’s atmosphere.”