The BeLaU Spherules from IM1’s Site Are Not Coal Ash

On 8 January 2014, US government satellite sensors detected three atmospheric detonations in rapid succession about 84 kilometers north of Manus Island, outside the territorial waters of Papua New Guinea. <a href="https://iopscience.iop.org/article/10.3847/1538-4357/ac8eac/pdf" rel="noopener ugc nofollow" target="_blank">Analysis</a> of the trajectory suggested an interstellar origin of the meteor. The object, labeled IM1 for Interstellar Meteor 1, arrived with a velocity relative to Earth of more than 45 kilometers per second and originated from outside the plane of the ecliptic. On 1 March 2022, the US Space Command issued <a href="https://lweb.cfa.harvard.edu/~loeb/DoD.pdf" rel="noopener ugc nofollow" target="_blank">a formal letter to NASA</a> certifying a 99.999% likelihood that the object was interstellar in origin. Along with this letter, the US Government released the <a href="https://lweb.cfa.harvard.edu/~loeb/lightcurve.pdf" rel="noopener ugc nofollow" target="_blank">fireball light curve</a> as measured by satellites, which showed three flares separated by a tenth of a second from each other. The bolide broke apart at an unusually low altitude of about 17 kilometers. The object was substantially stronger than any of the other 272 objects in the <a href="https://cneos.jpl.nasa.gov/fireballs/" rel="noopener ugc nofollow" target="_blank">CNEOS catalog of fireballs</a> compiled by NASA, including the 5%-fraction of iron meteorites from the solar system. Calculations of the fireball light energy suggest that about 500 kilograms of material was ablated by the fireball and converted into ablation spherules with a small efficiency. The fireball path was <a href="https://arxiv.org/pdf/2303.07357.pdf" rel="noopener ugc nofollow" target="_blank">localized</a> to a kilometer-wide strip based on the delay in arrival time of the direct and reflected sound waves to a seismometer located on Manus Island. <a href="https://avi-loeb.medium.com/the-belau-spherules-from-im1s-site-are-not-coal-ash-7b818dd5f452">Website</a>