It’s a conspiracy theory so prevalent it has entered the mainstream. Everyone, it seems, has heard of the idea that the US government is sitting on proof that extraterrestrials exist and have been visiting Earth for decades.
It’s easy to dismiss such stories, but seriously, could there be even a small amount of truth in it? Could extraterrestrial probes really be functioning near Earth? We don’t know. But Harvard astronomer Prof Avi Loeb’s Galileo Project aims to investigate.
What used to be called UFOs (unidentified flying objects) have now been retitled as UAPs (unidentified aerial phenomena). In a blow against the conspiracy theorists, a report from the US Office of the Director of National Intelligence was released in 2021 detailing the UAPs they had been investigating.
According to the document, 144 UAP reports were made between 2004 and 2021 mostly from military personnel. Few conclusions could be drawn, however, because the actual data was limited and difficult to analyse, and that’s where Loeb plans to help out.
“I think the government is puzzled. They don't know what to make of it. They are not scientists,” says Loeb, “I say let's just figure it out, let's not have any prejudice, just collect better data. That's the scientific method. That's the way science is done.”
The goal of the Galileo Project is therefore to transform the search for extraterrestrial technological signatures from accidental or anecdotal observations “to the mainstream of transparent, validated and systematic scientific research” according to the project’s website.
To collect such data, the project team has assembled a special observatory at Harvard University in Cambridge, Massachusetts. It monitors the entire sky, tracking everything that passes overhead. The trick, according to Loeb, was adapting the equipment to track fast-moving objects because when looking out into the distant universe, astronomical telescopes are never required to move quickly.
Loeb had become interested in using science to investigate the idea of extraterrestrial visitation back in 2017, when astronomers discovered the unusual asteroid ‘Oumuamua. Discovered as it was leaving the Solar System, ‘Oumuamua was unusual in that it appeared to be roughly cylindrical rather than potato-shaped as is usual for asteroids. It also appeared to accelerate in a way that could not be explained by the gravity of the Solar System.
Most astronomers assumed that it must have released some gas, like a comet, causing it to accelerate. But Loeb found himself thinking that it would be the exact type of behaviour that you would expect from an alien spacecraft.
He noticed another coincidence too. Six months before ‘Oumuamua’s closest approach to Earth, a metre-sized meteor hit the Earth. Its speed and trajectory indicated that it came from outside the solar system. Although its orbit was not correlated with ‘Oumuamua’s, it inspired him to consider the possibility of an interstellar craft releasing small probes to investigate the planets it was passing.
He called these hypothetical probes ‘dandelion seeds’ and wondered whether any of the reported UAPs might fit the bill.
In 21 of the 144 reports, some sort of unusual movement was reported. Often this movement is extremely fast but as Loeb and Dr Sean M Kirkpatrick, who heads the Pentagon’s All-domain Anomaly Resolution Office, point out in their draft paper, extremely fast movement through the air results in an optical fireball – just like when meteors burn up in our atmosphere.
Instead, they suggest that the lack of a fireball could mean that the objects are closer to the observer than assumed, and therefore smaller and moving more slowly. But in order to know for sure better data is required, underlining the need for rigorous measurements.
Prof Michael Garrett, a radio astronomer at Jodrell Bank, University of Manchester, is vice-chair of the International Academy of Astronautics’ SETI Permanent Committee. He sees Project Galileo as a bridge between two subjects that have traditionally been widely separated: UFOlogy and the Search for Extraterrestrial Intelligence.
Whereas both disciplines have been viewed with extreme scepticism, or even ridicule by the scientific community, the latter has now managed to establish itself as a valid scientific avenue of enquiry. In SETI, radio astronomers use their telescopes to listen for any extraterrestrial signals passing by Earth.
“If I accept that there's intelligence out there, and that might have been around for a long time, I also have to accept that there might be phenomena, including phenomena that could visit us, that's associated with intelligence. I can’t somehow think there might be intelligence somewhere on the other side of the galaxy, and then say, 'oh, yeah, but it can't be here'. Those two things to me don't make sense and are not logical,” says Garrett.
The first data from Loeb’s prototype observatory is expected this summer. However, it is based at just one site. To make real progress he needs more. His team are now constructing copies to be deployed elsewhere in America. If they can attract the necessary funding of tens of millions of dollars, they plan to extend these observatories across the world. He is then hopeful that they will collect the data required.
“It's basically like multiplying the number of objects that we monitor. To get to the bottom of this we have to have enough locations to get good statistics, and clarify whether there is anything other than natural or human-made objects,” says Loeb.
About our expert, Prof Avi Lob
Avi is the Frank B. Baird Jr. Professor of Science at Harvard University. He holds a visiting professorship at the Weizmann Institute of Science and a Sackler Senior Professorship by special appointment in the School of Physics and Astronomy at Tel Aviv University. He is als the author of several books including Extraterrestrial: The First Sign of Intelligent Life Beyond Earth.
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