Corroded Iron and Volcanic Debris in IM1’s Path

Avi Loeb
6 min readJun 18


Diary of an Interstellar Voyage: Part 14 (June 19, 2023)

We keep running and thinking on Silver Star. Avi Loeb at his routine 3-mile jog every morning before sunrise, listening to a podcast on his wireless earbuds.

My daily jog at an average speed of 3 miles in 24 minutes did not bring me out of the boundary of the ship’s deck. The reason is simple: there is a vast ocean beyond that boundary. My cell phone app measured the effective distance that I would have traversed if I were let free on land. It occurred to me that irrespective of how much effort we put into our daily routines, we sometimes run in circles. The key is to open our minds to the broader horizon out there.

As the Sun was rising, I looked at the huge body of water surrounding the boat. This ocean has an all-encompassing reality here, with a nearly uniform appearance except for small ripples, much like the Universe at large. Yet, we tend to live our life and focus all of our attention on the boat that carries us. In the cosmic case — the boat is our home planet, the Earth. Last night we asked the boat captain to turn off the deck’s lights so that we could see better the Milky Way stars overhead. The majestic view left me in awe. I could not avoid wondering: what if there is a different world out there, hidden from our limited view, like life in the depths of the ocean? In the latest video footage taken by our underwater sled, I noticed shrimp and fish swimming in front of the sled at a depth of 2 kilometers underneath our boat, Silver Star. To see them, we had to send a camera to a great distance. Similarly, to find intelligent partners in our cosmic neighborhood we have to work hard in seeking the evidence, as a substitute to the lazy mantras “where is everybody? … extraordinary claims require extraordinary evidence…”.

While surveying the floor of the Pacific Ocean for 12 hours, our latest Run 6 saturated the sled magnets by scooping material from the likely crash path of the first recognized interstellar meteor, IM1. By now, our expedition team members Rob Millsap and Art Wright mastered the technique of keeping the sled on the ocean floor, while Jeff Wynn and Ryan Weed mastered the technique of characterizing the composition of the harvested materials.

After Run 6 that lasted 12 hours, the sled magnets were fully saturated. Rob Millsap directed the winch cable as the sled was lowered on deck, like a fisherman that has just caught fish.

As I approached the sled, I noticed a rock stuck in between two lead weights. Jeff Wynn conjectured that it might be coral or a natural product of a nearby volcano. Indeed, the video footage from the sled cameras showed a debris field full of volcanic rocks.

Rob Millsap watching the video footage of Run 6 after a sleepless day.

Examination of some fragments by our electronic microscopes showed small particles of either biological or geological origins.

The only anomaly in Run 6 was a collection of pieces of corroded iron, which I quickly dried up with a hair dryer and handed over to Ryan Weed for a composition analysis.

The anomalies in Run 6: pieces of corroded iron and a rock. The stretched-out microphone of the filming crew can be seen in the background of the top image, behind Avi Loeb’s hand.

With enough material, our gamma-ray spectrometer could infer whether the volcanic ash or the corroded iron pieces were produced before or after August 1945, based on whether they carry radioactive isotopes that contaminated Earth after atomic bombs were dropped on Hiroshima and Nagasaki.

A microscope image of magnetized particles mixed with planktonic debris, taken by Jeff Wynn.
A microscope image, taken by Jeff Wynn, of a clump of vesicular tephra with an entrained magnetite particle.

Upon launching Run 7, the winch cable jumped the pulley and shifted between the pulley frame and the pulley disk at a height of 7 meters on a heaving deck with a thunderstorm on the horizon. The UK-based oceanographer Toby Adamson, who sleeps on the bed below mine in our shared bunk, spliced the cable in record time with a splice that is 95% as efficient as the original tensile strength. This startling experience after midnight brought Rob Millsap out of bed after a sleepless day and convinced me beyond any doubt that we have an exceptional A-team of professionals on Silver Star.

Around the time that we started examining the harvest from Run 6, I received an email that my paper with Professor Thiem Hoang, about `Oumuamua not being a water iceberg — as suggested recently, has been accepted for publication after peer review in the prestigious scientific outlet, The Astrophysical Journal Letters. I decided to write to some science journalists in major newspapers who concluded several months ago that `Oumuamua’s nature has been resolved as being a natural object. My email read as follows:

“Dear Science Reporter,

Following on our past correspondence concerning the Bergner & Seligman paper in Nature that you reported about on March 22, 2023, you may find at this link the final (accepted for publication) version of my paper with Professor Thiem Hoang, showing that their model is untenable as an explanation for the non-gravitational acceleration of `Oumuamua.

Bergner & Seligman neglected to include evaporative cooling in calculating the iceberg temperature and exaggerated the hydrogen propulsion as a result. At the surface temperature they used, evaporative cooling is orders of magnitude larger than the terms they included in their energy balance equation. As a result of the evaporative cooling, not enough hydrogen is available to reach the surface by annealing at a temperature T>30K and propel `Oumuamua. Even if a surface layer happens to be made of pure molecular hydrogen, it will not survive the journey through interstellar space as a result of heating by starlight. Long-period comets from the Oort cloud originate outside the heliosphere, are exposed to the same interstellar conditions as interstellar comets and do not show pure hydrogen propulsion. Indeed, the truly interstellar comet, 2I/Borisov, resembled solar system comets.

The Hoang & Loeb paper is now accepted for publication in The Astrophysical Journal Letters, following peer review. For a broader perspective, see my essay here.

We would be grateful if you could mention the above oversight of Bergner & Seligman, since the public deserves to know the truth on scientific matters. We cannot ask our politicians to be more truthful about scientific matters than our science reporters.

With gratitude,


Abraham (Avi) Loeb
Frank B. Baird Jr. Professor of Science; Director, Institute for Theory & Computation, Harvard University

Professional website


After sending the emails, it occurred to me that we will keep running our operation and thinking about it on the deck of Silver Star, irrespective of what these science reporters and their followers do.


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 chairs the advisory board for the Breakthrough Starshot project, and 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. His new book, titled “Interstellar”, is scheduled for publication in August 2023.



Avi Loeb

Avi Loeb is the Baird Professor of Science and Institute director at Harvard University and the bestselling author of “Extraterrestrial” and "Interstellar".

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