How we search for intelligent life in the cosmos matters

Sadly, the visionary radio astronomer Frank Drake recently passed away. When the Breakthrough Listen initiative was announced in 2015, I had the privilege of sitting next to Drake during a banquet dinner preceding a panel discussion about the search for extraterrestrial intelligence (SETI). Drake pioneered radio SETI with Project Ozma in 1960. For the 62 years that have elapsed since then, the SETI effort focused on the search for radio or laser signals from distant civilizations.

This traditional SETI approach is equivalent to waiting for a ringtone on our phone. To receive an electromagnetic signal, we need the sender to transmit it exactly a light-travel-time ago with similar communication technologies to those we developed over the past century. This runs the risk of not detecting any transmission since signals from other intelligent life in the stars could have been sent billions of years ago.

The likelihood for a phone call is highly uncertain, as Drake quantified in his famous Drake equation. With no ring from our phone, we kept reflecting on Enrico Fermi’s question: “Where is everybody?”

Gladly, there is an alternative search method. It involves checking for physical packages in our mailbox.  Even if radio-transmitting civilizations are dead by now, their packages might have piled up in our cosmic neighborhood since these packages move slowly and are bound by gravity to the Milky Way disk.

Over the past year, NASA and the U.S. intelligence agencies have encouraged the scientific community to study the nature of Unidentified Aerial Phenomena (UAP) near Earth. Their request inspired the Galileo Project at Harvard University, which I lead. It follows the alternative path to traditional SETI. The time is ripe for academia to engage more broadly with the new All-domain Anomaly Resolution Office (AARO) in an effort to explain the unknown nature of an unusual subclass of Near-Earth Objects.

I was recently asked, “If a spaceship landed in your backyard, would you board it?” My answer was a resounding yes.But most likely, we will never be offered a ride to exotic interstellar destinations for the same reason that ants on the sidewalk are not offered rides by bikers who traveled from far away. In fact, the bikers might barely notice these ants. Moreover, the bikers’ language, technological equipment, and intellectual aspirations are entirely foreign to the rituals of an ant colony. It is pure fantasy for the ants to imagine that the bikers would say, “take us to your leader,” just as it is for Neil de Grasse Tyson to expect having dinner with extraterrestrials in New York City.

Could we identify an encounter with something that we cannot comprehend? Absolutely. The search technique is straightforward: The object should not resemble familiar entities. These include natural objects like insects, birds, thunderstorms or rocky meteors and human-made objects like drones, weather balloons, bullets, artillery shells, missiles, airplanes and satellites. There is no need for us to reverse engineer the objects we detect. UAP could comply with known physics and still represent an unfamiliar technology.

New physics is a high bar that should only be contemplated when the data demands it without a reasonable doubt. Any new physics must be universally accessible and reproducible through experimental data on multiple systems. In fact, we might harness it ourselves after fully understanding how it works.

If functional devices arrived at Earth, their manufacturers were likely far more technologically advanced than we are. Our current interstellar probes will take tens of thousands of years before they exit the Oort cloud of our solar system and enter interstellar space. Future light sail technologies, inspired by Breakthrough Starshot, could enable interstellar travel at a higher speed.

Near-Earth Probes (NEP) are a new subclass of Near-Earth Objects that could be equipped with artificial intelligence (AI). Should we be worried about the risk from the unknown? Not at all. If the unknown wanted to harm us, it likely would have done so long ago. We should collect scientific-quality data and use our best AI systems to interpret it.

The task before us is to humbly study any new evidence on NEP. The reality in interstellar space remains the same irrespective of what is popular on social media or in academia. Let us be as open minded as students on their first day in class. This is the true legacy of Frank Drake.

Avi Loeb is the head of the Galileo Project at Harvard University, founding director of Harvard’s Black Hole Initiative, director of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics and the former chair of the astronomy department at Harvard University (2011-2020). He chairs the advisory board for the Breakthrough Starshot project, and he is a former member of the President’s Council of Advisors on Science and Technology and a former chair of the Board on Physics and Astronomy of the National Academies. He is the bestselling author of “Extraterrestrial: The First Sign of Intelligent Life Beyond Earth” and a co-author of the textbook “Life in the Cosmos,” both published in 2021.