THE HARVARD ASTROPHYSICIST
Loeb is the Frank B. Baird Jr. Professor of Science at Harvard, where he chaired the astronomy department from 2011 to 2020, directs the Institute for Theory and Computation, and was founding director of the Black Hole Initiative. Most of his long publication record is conventional astrophysics: the first stars, black holes, the early universe. His public profile comes from a much smaller part of his work, on objects he argues may be artificial.
'OUMUAMUA
In October 2017 the Pan-STARRS telescope in Hawaii found 'Oumuamua, the first known object to pass through the solar system from interstellar space. It was elongated or flattened, had no visible tail, and sped up slightly as it left the Sun in a way gravity alone did not explain. In 2018 Loeb and Shmuel Bialy proposed that it could be a thin light sail pushed by sunlight, and his 2021 book Extraterrestrial argued that an artificial origin should not be ruled out without study. Most astronomers favor natural explanations, such as a fragment of hydrogen or nitrogen ice whose outgassing left no visible tail.
THE GALILEO PROJECT
In July 2021 Loeb founded the Galileo Project, an effort to bring systematic, instrument-based science to the search for anomalous objects. Its observatories record the sky continuously with calibrated optical, infrared, radio and audio sensors, so that an unusual object would be captured as data rather than as a single eyewitness clip. The approach is the opposite of most UFO research, which starts from a report and works backward.
THE PACIFIC METEOR EXPEDITION
In June 2023 Loeb led an expedition off Manus Island, Papua New Guinea, to recover fragments of a 2014 meteor that U.S. government sensors had recorded and that he and a student had argued came from outside the solar system. The team dredged tiny metallic spherules from the seafloor and reported an unusual composition. Other scientists disputed both the interstellar origin and the reading of the spherules, and the debate is still open in the journals.
3I/ATLAS AND THE CRITICS
In 2025 he made a similar case about 3I/ATLAS, the third known interstellar object, discovered that July; most astronomers treat it as a natural comet. His critics say he raises the artificial hypothesis too readily and promotes it before peer review. His answer is that science should test unlikely ideas with data rather than dismiss them, which is also the stated purpose of Galileo.
SCIENCE AND THE RECORD
Loeb's posture is a useful lens on the PURSUE files. He is neither a true believer nor a reflexive debunker; he insists the only honest path is measurement. That is exactly the spirit in which Umbra presents the record: the primary sensor data and documents, rendered as released, for you to assess. For the government's own approach, see AARO and the UAP Science Advisory Council.
Who is Avi Loeb?
A Harvard astrophysicist, the Frank B. Baird Jr. Professor of Science, who chaired Harvard's astronomy department from 2011 to 2020. He is known publicly for arguing that some interstellar objects could be artificial and for founding the Galileo Project.
What did Avi Loeb say about 'Oumuamua?
That its shape and its small non-gravitational acceleration were unusual enough that it might be a thin artificial light sail, an idea he set out in a 2018 paper with Shmuel Bialy and in his 2021 book Extraterrestrial. Most astronomers favor a natural explanation.
What is the Galileo Project?
A research effort Loeb founded in 2021 to search for anomalous objects with purpose-built observatories that record the sky in several wavelengths, so any unusual object is captured as calibrated data.
What did the 2023 Pacific expedition find?
Tiny metallic spherules dredged from the seafloor near Manus Island, which Loeb's team linked to a 2014 meteor they argue was interstellar. Other scientists dispute both the origin and the interpretation.
Is Avi Loeb part of the government UAP program?
No. He works independently through Harvard and the Galileo Project. The government's UAP work runs through AARO and the records published under PURSUE.
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