A Toast of Champagne for Fifty IM1 Spherules and Beyond!

Avi Loeb
4 min readJun 27, 2023


Diary of an Interstellar Voyage, Report 33

(June 27, 2023)

Sunset at the successful conclusion of the Interstellar Expedition. Art Wright (left) and Avi Loeb (right), share their affection for IM1’s site in the Pacific Ocean (June 27, 2023).

We just had a toast of champagne at dinner time on the deck of Silver Star, celebrating the discovery of 50 spherules totaling 35 milligrams near the fireball path of the first recognized interstellar meteor, IM1.

Rob McCallum (left) pouring champagne in celebration of “mission accomplished” at retrieving spherules from the first recognized interstellar meteor, IM1 (June 27, 2023).

The spherules were found primarily along the most likely path of IM1 and not in control regions far from it. In the coming weeks we will analyze their elemental and isotopic composition and report our data in a paper submitted to a peer-reviewed journal. The interpretation will be left to follow-up papers. Given IM1’s high speed and anomalous material strength, its source must have been a natural environment different from the solar system, or an extraterrestrial technological civilization.

The final count of 50 spherules in the size range of 0.1–1 millimeters. This whiteboard will decorate Avi Loeb’s office at Harvard.

By the end of this week, we hope to know more about the elemental and isotopic composition of IM1. In response to the nay-sayers we say nothing other than show our data in our first publication. One cannot argue with facts, only with interpretations.

There were over a million verified views worldwide of my 33 diary reports over the past couple of weeks. Science can be exciting when it resonates with the passion of the public.

When looking at the beautiful sunset over the horizon in the company of Art Wright, I could not help but wonder whether the treasure is yet to be found at IM1’s location. Finding a large relic of IM1 on the ocean floor based on the spatial distribution of spherules in our 26 runs through the 10 kilometers region around IM1’ s fireball will be our common goal for the coming year.

I will miss the breathing noise of Silver Star’s engine as it retrieves the sled with black powder attached to its magnets. At first, we regarded this volcanic ash as background but within a week we realized that our signal is embedded in it in the form of metallic marbles of sub-millimeter size and a milligram mass. Back at Harvard, my daughter, Lotem, will use tweezers to separate the abundant population of small spherules of size below 100 microns which we were unable to separate on the rocking ship. By plotting the size distribution of spherules, we can infer whether there is a lower or an upper cutoff to their population.

Pulling up the magnetic sled in Run 25 (June 27, 2023). There is one more run to go before the retrieval of spherules concludes.

Run 25 delivered a piece of painted debris which was verified as TiO2 paint, commonly used by humans after 1915. I noted: “anything produced by humans is of no interest to this expedition.”

Avi Loeb holding a magnetic piece of debris painted in white, with a composition of a human-made TiO2 paint. Art Wright appears in the background with his back to the camera.

The final listing of events and spherules sealed a busy schedule of two weeks during which my sleep hours were uncorrelated with the position of the Sun in the sky.

Cheers to future interstellar expeditions, including in outer space!

Final listing of events in the last day of the Interstellar Expedition.
Final box of 50 spherules. Mission accomplished!


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".