Just as with Large Language Models, the quality of our thoughts is dictated by our training dataset. Babies receive most of their training dataset from the environment around their crib. Once they learn how to crawl and then to walk, the training dataset expands to a larger space within their home. Often, the steady attention they receive from their parents leads them to believe that they are located at the center of the Universe. Their early training suggests unequivocally that they are unique and special.
Enter their first day at kindergarten. The same kids realize for the first time that there are many more entities like them. This shocking realization is supplemented by the discovery that some of these strangers are even more intelligent. This delivers a direct blow to the ego. Welcome to adulthood!
Let me be clear: our very best astrobiologists have not matured yet to cosmic adulthood. They got used to the training dataset of their home on Earth, where humans treat each other as the pinnacle of creation since the Big Bang, 13.8 billion years ago. Public figures like Carl Sagan and Elon Musk argue persistently that the existence of extraterrestrial life, not to speak about beings more intelligent than us, is an “extraordinary claim that requires extraordinary evidence”.
But the sobering truth is that our own Milky-Way galaxy contains on the order of a hundred billion Earth-Sun systems which could host the chemistry of life-as-we-know-it. Common sense would argue that our kindergarten contained many kids smarter than we over the past 13.8 billion years. This is an ordinary claim that requires ordinary evidence. Unfortunately, common sense is not common in academia, as much as it is not common among pre-kindergarten infants. Even after observing many homes like theirs from the windows of their home, they could insist that the concept of these homes containing attention-deserving infants similar to them, is an extraordinary claim that requires extraordinary evidence. Remarkably, unfamiliar infants might be delivered by visitors to their home, in which case their existence would be undeniable.
This week, a new scientific paper reported results from the analysis of fragments retrieved from the asteroid Bennu in October 2020 by NASA’s 1.2 billion dollar mission OSIRIS-REx. The retrieved 122-gram sample is uniquely pristine, free from any terrestrial contamination that characterizes meteorites which interact with the Earth’s atmosphere and crust. The new analysis discovered that Bennu contains all 5 nucleobases that form DNA and RNA on Earth and 14 out of the 20 amino acids in known proteins. Whereas terrestrial amino acids that make all living organisms have a ‘left-handed’ molecular structure, those found in Bennu contain nearly equal quantities of left and right-handed structures. This mirror-symmetry must have been broken once terrestrial life emerged from a symmetric reservoir of amino acids delivered to Earth by Bennu-like asteroids.
The carbonaceous material that makes Bennu likely originated from the collisional breakup of a much larger parent body in the inner asteroid belt, which contained hot water channels. In a companion paper, other scientists reported that Bennu is also rich in salts created billions of years ago, when watery ponds on Bennu’s parent asteroid evaporated. These ponds could have led to the chemistry of life-as-we-know-it, yet no signs of such forms of life were found on Bennu.
These discoveries imply that proto-planets in the early solar system developed the building blocks of life. If they did so, then the long-lived ocean under the icy surface of Saturn’s moon Enceladus or Jupiter’s moon Europa — to be studied by the recently launched Europa-Clipper, may contain microbial life right now, waiting to be discovered.
The sobering message from Bennu is that extraterrestrial life should be regarded as an ordinary claim. Our Galactic kindergarten might have included many kids like us over the past 13.8 billion years.
We can learn about dead extraterrestrial civilizations by searching for the artifacts they produced in interstellar space over the past billions of years. The most abundant interstellar relics might be in the form of space trash carried by stellar winds when their host stars became giants. Human-made space trash from broken satellites is commonly labeled “empty trash bags objects” by sky watchers. These objects possess a large surface area per unit mass and exhibit non-gravitational acceleration from solar radiation pressure, similar to that exhibited by the first interstellar object recognized by us, `Oumuamua.
Under my leadership, the Galileo Project is currently constructing four observatories that would monitor the sky in search for anomalous interstellar objects. We are also planning a new expedition to retrieve large fragments from the crash site of the interstellar meteor IM1, whose fireball was spotted over the Pacific Ocean by U.S. government satellites in January 2014. Thanks to the generosity of the visionaries Dr. Frank Laukien and Eugene Jhong, we are about to receive this month the funds necessary to complete the full analysis of the millimeter-size fragments retrieved in our 2023 expedition to IM1’s site. Our latest scientific analysis of the retrieved fragments, at a cost of merely 0.1% of the OSIRIS-REx mission, resulted in two peer-reviewed papers published recently here and here.
Humanity will mature only if astrobiologists will open their mind to studying anomalous objects in space. This lesson was learned from the pioneering research of Galileo Galilei who discovered in January 1610, exactly 415 years ago, four points of light orbiting Jupiter. On February 20, 2025, we will celebrate Galileo’s legacy in my office at the Harvard College Observatory by unveiling a bronze sculpture titled: “Galileo Looking at the Four Moons of Jupiter.” This new sculpture was created by the renowned artist Greg Wyatt who was described by Sir Professor Stanley Wells as `America’s Rodin’. The sculpture is being donated by the Newington-Cropsey Foundation in celebration of the Galileo Project, which also received millions of dollars in donations over the past month and whose scientific publications are listed here. The event will feature a musical performance by the composer David Ibbett, the artist in residence at the Center for Astrophysics | Harvard & Smithsonian.
We must all keep in mind that the true intellectual center of astrophysics might be located on an exoplanet around a star that formed billions of years before the Sun. The scientists in that center might know what preceded the Big Bang, what lies inside black holes as well as the nature of dark matter and dark energy. If so, they are likely to be humble in recognizing how prevalent life and intelligence are in the cosmos. The sign of cosmic intelligence is the desire to seek a larger training dataset.
Arrogance is a marker of ignorance.
ABOUT THE AUTHOR
Avi Loeb is the head of the Galileo Project, founding director of Harvard University’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 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. The paperback edition of his new book, titled “Interstellar”, was published in August 2024.
