The BeLaU spherules are a collection of microscopic, metallic spheres enriched in beryllium (Be), lanthanum (La), and uranium (U), discovered during a 2023 oceanic expedition led by Harvard astrophysicist Avi Loeb. This mission aimed to locate remnants of a meteor, designated IM1, which entered Earth’s atmosphere in 2014 and was hypothesized to be of interstellar origin
due to its high velocity and unusual material strength. Avi Loeb, born in 1962 in Israel, is an Israeli-American theoretical physicist and astrophysicist known for his extensive work in cosmology, black holes, and the search for extraterrestrial life. He is the Frank B. Baird Jr.1
Professor of Science at Harvard University, where he served as the longest-tenured chair of the Department of Astronomy from 2011 to 2020. Loeb has made significant contributions to the study of the first stars, the formation of black holes, and the nature of dark matter. He gained widespread attention for his hypothesis that the interstellar object ‘Oumuamua could be an artificial extraterrestrial probe.
Loeb has authored over 700 scientific papers and several popular science books, including Extraterrestrial: The First Sign of Intelligent Life Beyond Earth. He is also the founding director of Harvard’s Black Hole Initiative and heads the Galileo Project, which aims to search for physical evidence of extraterrestrial technological artifacts. The expedition involved towing a magnetic sled across the seafloor near Papua New Guinea, resulting in the retrieval of
approximately 700 spherules ranging from 0.05 to 1.3 millimeters in diameter. Subsequent analyses revealed that about 22% of these spherules exhibited compositions indicative of planetary igneous differentiation, distinct from known solar system materials. Notably, a subset termed “BeLaU” spherules displayed extreme enrichments in Be, La, and U
—up to three orders of magnitude greater than typical solar system abundances. These findings led researchers to propose that the spherules might have originated from a differentiated magma ocean2 on an exoplanet with an iron core, suggesting an extrasolar provenance. However, the discovery has been met with skepticism within the scientific community.
Critics argue that the spherules’ compositions closely resemble terrestrial materials, particularly those associated with industrial pollution. Some suggest that the spherules could be microtektites3 formed from terrestrial laterites, linked to known impact events like the Australasian tektite strewn field4.
Additionally, the reliability of the trajectory data used to locate the meteor’s impact site has been questioned, with some attributing the seismic signals to non-meteoric sources, such as nearby vehicular activity. The debate surrounding the BeLaU spherules underscores the challenges in distinguishing between extraterrestrial and terrestrial origins of such materials. While the unique elemental enrichments are intriguing, they are not definitive proof of an interstellar source. Further interdisciplinary research is essential to unravel the true nature and origin of these spherules, balancing open-minded inquiry with rigorous scientific scrutiny.
Footnotes
- Frank B. Baird Jr. was a benefactor whose foundation established the Frank B. Baird Jr. Professorship of Science at Harvard University, recognizing outstanding scientists within the Faculty of Arts and Sciences. Notable holders of this title include Professor Avi Loeb, appointed in 2012, and Professor Neil Shephard, appointed in 2017. ↩︎
- A differentiated magma ocean refers to a molten planetary layer that undergoes chemical separation as it cools and solidifies, resulting in distinct layers of varying composition. This process typically occurs on planetary bodies during their early formation when intense heat from accretion and radioactive decay melts the outer layers. As the molten material cools, heavier elements like iron and nickel sink to form a dense core, while lighter silicate minerals rise to create the mantle and crust. This differentiation is crucial for understanding planetary evolution and the geochemical characteristics of rocky bodies in the solar system and beyond. Evidence of differentiated magma oceans is observed in Earth’s early history and on planetary bodies such as the Moon. ↩︎
- Microtektites are tiny, glassy spherules formed from terrestrial debris that melts and is ejected into the atmosphere during meteorite impacts. These particles are typically less than 1 millimeter in size and are found in marine sediments and other geological deposits. Their formation involves the intense heat and pressure generated during an impact event, which vaporizes rock material that subsequently cools and condenses into glassy droplets. Microtektites are often associated with larger tektite strewn fields and are valuable indicators of past impact events, providing insights into Earth’s geological history. They are commonly composed of silica-rich glass and may contain bubbles, inclusions, or distinctive surface textures. ↩︎
- The Australasian tektite strewn field is the largest known tektite deposit on Earth, covering an area of about 10% of the planet’s surface and spanning parts of Southeast Asia, Australia, and the Indian Ocean. Formed approximately 790,000 years ago, this strewn field resulted from a massive meteorite impact, believed to have occurred in Southeast Asia, possibly in present-day Laos or southern China. The impact ejected molten terrestrial material into the atmosphere, which rapidly cooled and solidified into glassy tektites that rained down across the region. These tektites vary in size and shape, with distinctive forms such as splash droplets, dumbbells, and discs. The Australasian strewn field is unique for its extensive distribution and abundance, making it a key subject of study in impact geology. ↩︎
Further Reading
Sources
- The Galileo Project “Spherule analysis finds evidence of extrasolar composition” https://projects.iq.harvard.edu/galileo/news/spherule-analysis-finds-evidence-extrasolar-composition
- Medium “The BeLaU Spherules from IM1’s Site Are Not Coal Ash” https://avi-loeb.medium.com/the-belau-spherules-from-im1s-site-are-not-coal-ash-7b818dd5f452
- USA Today “Metallic spheres found on Pacific floor are interstellar in origin, Harvard professor finds” https://www.usatoday.com/story/news/nation/2023/08/29/metallic-spheres-interstellar-origin-avi-loeb-finds/70699783007/
- LiveScience “‘Alien’ spherules dredged from the Pacific are probably just industrial pollution, new studies suggest” https://www.livescience.com/space/extraterrestrial-life/alien-spherules-dredged-from-the-pacific-are-probably-just-industrial-pollution-new-studies-suggest
- Big Think “Harvard astronomer’s “alien spherules” are industrial pollutants” https://bigthink.com/starts-with-a-bang/harvard-astronomer-alien-spherules/
- Independent “Scientists give verdict on Harvard professor’s claim of finding materials in sea from outside Solar System” https://www.independent.co.uk/space/harvard-professor-materials-outside-solar-system-b2406910.html
- Earth “Harvard scientist finds alien artifacts at the bottom of the Pacific Ocean” https://www.earth.com/news/tiny-metal-spheres-from-the-pacific-ocean-may-earths-first-alien-objects/
- NewScientist “Have interstellar meteor fragments really been found in the ocean?” https://www.newscientist.com/article/2390244-have-interstellar-meteor-fragments-really-been-found-in-the-ocean/
