(Space) trash talk

Professor Avi Loeb is on the search for evidence of interstellar civilizations.


The search for extraterrestrial life is one of the most exciting frontiers in science. However, scientists involved in technological interstellar archeology are not looking for little green aliens. Rather, they’re scouting for debris from explorations of the cosmos that have entered our galaxy.

On Wednesday, Oct. 19, at 6 pm, Professor Avi Loeb will speak about this search for interstellar artifacts, or, as he says, extraterrestrial “space trash” that has come from outside our solar system. Loeb’s credentials are voluminous — he’s the 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.

Interstellar artifacts have already been found entering our planetary system. For instance, CNEOS 2014–01–08 was detected in 2014 by U.S. government sensors near Papua New Guinea. The first interstellar meteor is an outlier, because it was moving faster than 95 percent of all the stars in the vicinity of the Sun, and it was tougher than all other 272 meteors in the NASA catalog. Loeb told The Times in a phone interview that “astronomers monitored this object, and it looked very unusual. Not like a regular comet. And there was a mysterious force pushing it. Usually you get such a force with a rocket effect, being propelled forward and ejecting the gases from their fuel backward.”

Loeb continues, “Moreover, it had a very strange shape. Most likely it was flat. I suggested that the force pushing it was actually a reflection of sunlight. For that, the object had to be very thin and like a sail that was being pushed by light, instead of by the wind. Nature doesn’t make such objects, so I said maybe it’s artificial; perhaps a cover of a spaceship that was torn apart and came our way.”

In 2017, the Pan-STARRS telescope in Hawaii found the unusual interstellar object “Oumuamua.” Importantly, “Oumuamua,” which in Hawaiian means “a messenger from afar, arriving first,” showed half-a-dozen anomalies relative to comets or asteroids in our solar system, including that it didn’t have a cometary tail.

Interestingly, this was perhaps not the first noted interstellar artifact. In 2019, Loeb was looking through a catalog of meteors that the government had compiled related to its missile warning system, and found an object from 2014 that, as he explains, “was definitely moving too fast to be bound to the sun. So this object too came from outside our solar system.” Furthermore, as with CNEOS 2014–01–08, the data revealed that it was tougher than iron and, in fact, tougher than all the 273 meteors in the catalog. It also had an unusual shape. Loeb concludes, “Therefore, maybe these two interstellar objects were outliers that came from an artificial origin.” 

In 2021, with donations from private funders, Loeb founded the Galileo Project, which will rely on scientific evidence to support its discoveries in searching for extraterrestrial technological relics. “If there is equipment that is reaching the earth from another civilization, we want to explore the evidence instead of saying everything in the sky is rocks. Also, we want to photograph ‘Oumuamua,’” Loeb says. And the Galileo Project is building instruments that will monitor the sky to try and identify the nature of the unidentified objects contained in a report released last year by the U.S. director of national intelligence. They then hope to openly analyze the data and report it to the public.

The Galileo Project is designing a space mission to rendezvous with interstellar objects like “Oumuamua,” and is planning an expedition to retrieve fragments from the first interstellar meteor, CNEOS 2014–01–08, from the ocean floor near Papua New Guinea. 

Loeb wants us to keep in mind that just as we send rockets and equipment into space, “It’s conceivable that there could be those from civilizations that predated us, because most stars come from millions of years before our sun, and a substantial fraction of them have planets like the Earth.”

Loeb adds that science should be based on evidence, and scientists are often guided by completely different motivations. “They want to show they are smart; they are experts. Therefore, they explain everything that is observed based on what they already know. They resist change in their point of view,” he says. 

Finally, Loeb wants us all to maintain our childhood curiosity: “When we are children, we learn about the world, and we’re not afraid of making mistakes. As adults, we often want to preserve our image so we don’t take risks. We subscribe to the beaten path so other people will not see us making mistakes. That’s a path that doesn’t lead to discovery. You have to take the path that was not taken in order to discover new things.”

Loeb will be speaking on Wednesday, Oct. 19, at 6 pm. Email tthorpe@clamsnet.org to sign up and get the Zoom invite. For more information, call 508-645-3360. To learn more about Loeb’s work, see cfa.harvard.edu/~loeb.