In his book Extraterrestrial, Harvard astrophysicist Avi Loeb suggests that a 2017 interstellar object known as 'Oumuamua is "interstellar technology built by aliens".

Inspired by partially by ‘Oumuamua, Loeb founded The Galileo Project in 2021 to "systematically search for extraterrestrial intelligence or extraterrestrial technology on and near Earth." Galileo planned and secured funding for an expedition to recover portions of an object known as CNEOS 2014-01-08, commonly called Interstellar Meteor 1 (IM1), which crashed of the coast of Papua New Guinea on January 8th, 2014.

IM1 became a target of interest for The Gallileo Project when Loeb and a student, Amir Siraj, submitted a preprint arguing—citing a US Department of Defense memo—that the object originated outside the solar system.

we identify the ∼0.45m meteor detected at 2014-01-08 17:05:34 UTC as originating from an unbound hyperbolic orbit with 99.999% confidence. The U.S. Department of Defense has since verified that "the velocity estimate reported to NASA is sufficiently accurate to indicate an interstellar trajectory."

If Loeb and Siraj are correct, then IM1 is the first interstellar object scientifically known to impact the earth. Other scientists have disputed their conclusions.

Based on IM1's observed toughness, Loeb believes that not only may the object be interstellar, but that it could be alien technology. To quote Loeb:

There are two general possibilities. Either IM1 is of new natural origin, or it is artificial, produced by an extraterrestrial technological civilization. Regarding the first possibility, X-ray imaging of the Vela supernova remnant revealed bow shocks from bullets flying out of the explosion site, a discovery I attempted to explain three decades ago. It is possible that IM1 was a small bullet tougher than conventional iron meteorites, shot out of an exploding star. But it is also possible that it was a spacecraft, a billion-year old equivalent of our interstellar probes. Just imagine a spacecraft like Voyager 1 & 2, Pioneer 10 & 11 or New Horizons, crashing onto a habitable exo-planet and burning up in its atmosphere. The exo-scientists on this exo-planet would regard the resulting exo-meteor as space trash. However, if they are curious enough to examine the composition of its fragments, they would realize that it was artificial in origin.

Using a massive magnetic sled to scrape the seabed, Loeb's expedition found 50 spherules which Loeb believes are portions of IM1. Loeb says these spherules are now being analyzed by "three laboratories in UC Berkeley, Harvard and the Bruker Corporation in Germany." Loeb is providing regular updates on his blog.

The fundamental question we will address is whether the elements and radioactive isotopes in the spherules have different abundances than solar system materials. If so, we would also check for any anomalies that might indicate a technological origin. For example, the melted material of semiconductors would include rare elements at a much higher abundance than found in nature.