Astronomer Kelsey Johnson Reflects on the Science Behind the Search for UFOs

Collage of images from a cockpit of an airplane over top of a fighter pilot helmet

Photo Illustration by Ziniu Chen, University Communications

“It was something not from the Earth,” U.S. Navy Cmdr. David Fravor, commanding officer of a squadron of F/A-18 Hornet fighter planes, said in an interview with the Washington Post about the fast-moving, Tic Tac-shaped UFO he sighted during a 2004 training mission over the California coast. The object moved unlike any aircraft he was aware of and seemed to defy nearby radar operators’ efforts to track it.

Fravor’s account of the incident remained classified for 13 years until the Department of Defense announced the formation of the Unidentified Aerial Phenomena Task Force in 2017 and charged it with the job of cataloging and analyzing sightings of strange aerial objects that could potentially represent a threat to U.S. national security.

Late in 2019, lawmakers asked the secretary of defense and director of national intelligence to submit a report on what the task force has learned about the objects we know as UFOs, and an unclassified version of that report is scheduled to be released later this month.

Government officials have already confirmed that the task force has found no evidence of alien spacecraft, but University of Virginia astronomer Kelsey Johnson, who is president-elect of the American Astronomical Society and also a former member of the National Science Foundation’s Astronomy and Astrophysics Advisory Committee, spoke with UVA Today about what the report might contain and what it might mean for those of us who are eager to catch a glimpse of extraterrestrial life.

Q. What do you think the government’s report on UFO activity is most likely going to tell us?

A. I think the report is likely to confirm that there have been sightings of objects in the sky that are currently unexplained. The catch is that just because something is “unidentified” does not mean that it was extraterrestrial life visiting Earth. If you are really bad at identifying things, then anything in the sky could technically be a UFO.

Taking the step to infer that the object is extraterrestrial in origin requires evidence – and in science we have a saying that “extraordinary claims require extraordinary evidence.” Finding evidence for extraterrestrial life would pretty much peg the meter on “extraordinary.”

Kelsey Johnson headshot

University of Virginia astronomer Kelsey Johnson is president-elect of the American Astronomical Society. (Photo by Dan Addison, University Communications)

That being said, regardless of the origin of objects in UFO sightings, I think these occurrences can be important to study and understand. Objects that have been observed by reliable witnesses and recorded to behave in unexplained ways absolutely merit legitimate scientific effort. Even if the explanation isn’t aliens, we might gain new insight into a natural phenomenon or better understand threats to national security. I find it really unfortunate that so much stigma has become attached to this topic – among both scientists and government officials. Yes, be skeptical and require evidence, but also be open-minded to explanations you cannot rule out.

This stigma has actually spun off a new term with less baggage: Unidentified Aerial Phenomena, or UAP.

Q. What kinds of phenomena are most likely reported as UFOs or UAP?

A. This depends on who is doing the reporting! For the general public, one of the underlying issues is that many people simply don’t spend a lot of time outside looking at the sky, so folks are not so familiar with objects that are totally normal. As a result, Venus, Mars and even the moon are frequently reported as UFOs. But there are also a number of less-common, but still 100% explainable, atmospheric phenomena that can appear pretty strange if you don’t know about them – everything from sun dogs caused by ice crystals in the atmosphere to really funky clouds. Lenticular clouds can do an especially great job mimicking Hollywood-style flying saucers.

Things get much harder to explain when there appear to be changes in motion that defy known modern technology. This is what has raised some eyebrows with the recent reports by the military. I am reminded of the “god of the gaps” fallacy, which is to say that just because we don’t understand something doesn’t mean the explanation is supernatural or alien.

Q. What might make some of these phenomena appear to be something other than what they are?

A. Human perception is fraught with issues and is extremely unreliable, and the need to be skeptical of personal accounts is amplified when something isn’t reproducible. We are also incredibly bad at gauging distances. If we don’t really know how far away something is, changes in motion are easily misinterpreted by our brains. For these reasons and others, it is essential to have actual data and measurements to test against different hypotheses.

Q. Are there good reasons for using federal or military funding for further research into these sightings?

A. I think it is always worthwhile to study things we don’t understand. That is how we make progress toward understanding the universe we live in. Truly unexplained phenomena with associated data should not be sitting on a shelf – these could reveal something very cool about the natural world or a novel technology that could be beneficial or threatening.

Q. How could science benefit from a renewed interest in extraterrestrial visitors?

A. Science is all about curiosity, and thinking about extraterrestrial life is rich ground for asking a huge range of questions. I absolutely love talking about and teaching these questions as a hook for inquiry – what forms might extraterrestrial life take? What environments might they need to live? How would they communicate? Would they even want to communicate? Considering these questions also gives us insight into ourselves and our own place in the universe.

Q. What is the likelihood that aliens have, in fact, visited Earth?

A. The likelihood that extraterrestrial life has visited Earth depends on a number of assumptions. I’m not going to give a specific likelihood, but I will say that with some basic assumptions, one could infer that the universe ought to be teeming with life.

Now whether extraterrestrial life is commonly able to survive and evolve into something more than a simple organism – let alone develop technology and travel across the galaxy – is the crux of the matter. Answering these questions goes beyond astrophysics and astrobiology into fields that don’t exist yet – like astrosociology and astropsychology.

Q. What kind of proof would scientists in those fields need to be sure?

A. To prove extraterrestrial life had visited Earth would require us being able to unequivocally rule out terrestrial origins, and that is tough. To “prove” something in the scientific sense, the phenomenon generally has to be repeatable so that hypotheses can be tested. With only fleeting and unpredictable sightings, it is virtually impossible to test hypotheses to verify or dismiss them. This leaves us wanting for real, tangible, physical artifacts that can be examined and tested by a range of scientists.

The late Arthur C. Clarke had three adages – known as Clarke’s Three Laws – the first of which was, “When a distinguished but elderly scientist states that something is possible, he [sic] is almost certainly right. When he [sic] states that something is impossible, he [sic] is very probably wrong.” We would all do well to use the word “impossible” with caution.

Q. How would you feel if extraterrestrial life were discovered?

A. I would be elated. If there is no other sentient life in the galaxy, that is a huge warning sign for humans and our potential for long-term survival. And how sad it would be for this enormous and grand universe to have so few to bear witness. I also think that finding other sentient life would bring about a beautiful renaissance of human thought and knowledge. I have to believe that our worldviews would change for the better if we had a deeper understanding that we are all truly on this tiny little planet together.

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