How the Light Gets In: The Interstellar Expedition Paper Was Accepted for Publication in the Prestigious Journal `Chemical Geology’
It took our team a full year to plan the expedition to the fireball site of the interstellar meteor IM1 in the Pacific Ocean. The location was determined by sensors aboard satellites of the U.S. Department of Defense, which detected the light from IM1’s brilliant fireball on January 8, 2014. Collecting spherules from the ocean floor was particularly challenging because the ocean is a mile deep at that location and the search region is 7 miles in length. Our team constructed a magnetic sled for the task, to be anchored to the ship called “Silver Star” by a 3-mile-long cable.
Thanks to a generous funding of 1.5 million dollars from Charles Hoskinson, we realized our scientific goal. The Interstellar Expedition team visited IM1’s impact site on June 14–28, 2023. We conducted an extensive towed-magnetic-sled survey over the seafloor and found about 850 molten droplets in the form of spherules of diameter 0.1–1.3 millimeters in our samples.
It took us a full year to analyze the retrieved materials. By now, a year after the expedition, we detailed our findings in an extensive scientific paper. The three referees of the paper recommended its publication after minor changes and the editor accepted the paper for publication after their thorough peer review. To all the critics, I can only repeat the words of Leonard Cohen: “There is a crack, a crack in everything. That’s how the light gets in.”
In the concluding paragraph of my message to the team of the Galileo Project Expedition about the acceptance of our peer-reviewed paper for publication, I wrote:
“Our team is now actively planning the next expedition. Here’s hoping that we will receive the funding for it soon.
It is a great pleasure to collaborate with all of you.
Avi”
To access our extensive paper and see the light that gets in through evidence-based science, click on the following link: Interstellar_Expedition_Final.pdf
Below I summarize the highlights of our findings.
The retrieved samples were studied by state-of-the-art laboratory instruments including a micro-X-Ray Fluorescence analyzer, Electron Probe Microanalyzer and an Inductive-Coupled-Plasma Mass-spectrometer. We identified 78% of the spherules as primitive with a composition that resembles the primordial material that made the solar system. When rocky planets like the Earth or Mars form with a hot molten rock (magma or lava ocean) on their surface as a result of bombardment by large bodies, some elements from the periodic table which have a chemical affinity to iron migrate towards the iron core and leave behind a modified abundance pattern, which we labeled as “differentiated”. Our analysis revealed that 22% of our spherules were differentiated.
Among the differentiated spherules, about half, namely 10% of the total number of spherules, had a chemical composition that was never reported before in the scientific literature, characterized by an enhanced abundance of some elements up to a thousand times larger than the standard solar composition. We labeled this special set: “BeLaU”-type spherules. The BeLaU composition is unfamiliar and different from the composition of the crust of the Earth, Mars, the Moon, asteroids and comets and potentially flags an origin from outside the solar system. This origin is unknown.
But curiosity-driven science never ends. The material analysis raises new questions: What is the age and material properties of IM1? Is IM1 natural or artificial in origin? Where did it come from and how long was its journey?
We are planning our next expedition for summer 2025, with the goal of answering these questions. Aside from identifying the nature of IM1, finding large pieces from its wreckage would allow us to determine its age from its radioactive isotopes, to find the composition of volatile elements that were lost from the spherules we retrieved, and also to gauge its material strength and thermal properties, potentially explaining why it maintained its integrity despite witnessing atmospheric stress beyond the tolerance of the toughest iron meteorites known in the solar system.
To find larger pieces of IM1, we intend to use a robot, namely a Remotely Operated Vehicle named Hercules, accompanied by a video feed that would allow us to see what we are picking up. Stay tuned! Science can be exciting.
Next week, I am scheduled to speak about the expedition at the world’s largest philosophy and music festival, titled: “How The Light Gets In”, in London, United Kingdom. I now have an interesting answer to the title of this festival. It is called the evidence-based scientific method.
ABOUT THE AUTHOR
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 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”, was published in August 2023.
