The subject has been thrust into the spotlight after a blob captured on a fuzzy video by Navy pilots raised questions over extraterrestrials.
The US government has been taking a hard look at unidentified flying objects like this one and a report summarising what the US knows about “unidentified aerial phenomena” — better known as UFOs — is expected to be made public this month.
Ahead of the release of the report, Futurist Dr Richard Hames told Yahoo News' Conspiracies Unpacked series Earth was just a "speck in this vast universe".
"To think that there is no other life than human life or the life on this planet, it would be ridiculous really," he said.
"If you just look at the immensity of the galaxies that are in this universe, it would be highly improbable that we are the only life form."
Dr Hames added people who had claimed to be abducted by aliens were "pretty normal people from all sectors of the population", however reports are more common among people from the UK and US.
He added TV shows like X-Files had given people an idea about alien life and possible experiences they may have had.
"I think particularly in the UK and the US, the cultural narrative around UFOs, alien life, abductions – especially with the influence of Hollywood – is so strong, and familiarity with that cultural narrative of course, it permeates itself into the psychology of people, there's no doubt about that," he said.
Dr Hames said however he did not believe aliens wanted to visit humans and simply wanted to observe.
"They might want to examine why we do the things we're doing," he suggested.
Senator says there's 'stuff flying in our airspace'
The anticipation surrounding the report shows how a topic normally confined to science fiction and a small, often dismissed group of researchers has hit the mainstream.
Worried about national security threats from adversaries, politicians ordered an investigation and public accounting of phenomena that the government has been loath to talk about for generations.
“There is stuff flying in our airspace,” Republican Senator Marco Rubio of Florida, one of the senators who pressed for the probe, recently told Fox News.
“We don't know what it is. We need to find out.”
Pilots and sky-watchers have long reported sporadic sightings of UFOs in US airspace, seemingly at unusual speeds or trajectories. In most cases, those mysteries evaporate under examination.
In 1960, the CIA said 6,500 objects had been reported to the US Air Force over the prior 13 years. The Air Force concluded there was no evidence those sightings were “inimical or hostile” or related to "interplanetary space ships," the CIA said.
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