Arttu Sainio

☄️ Of all of my space rocks, this Bjurböle is quite special, as it was recovered from the seabed, with great effort, in 1899. It is the only complete recovery of a meteorite at sea. Meteorites hit the Earth randomly, and thus ~70% of them hit the oceans and disappear forever. This claim was a reasonable assumption, since 71% of the Earth is covered by ocean, and it was recently verified by analysis of the world’s infrasound sensors used to monitor the nuclear Comprehensive Test Ban Treaty. The sensors recorded meteorite impacts by land and by sea, as seen in the B612 video here. Here’s is how this unique space rock recovery happened: on March 12, 1899, at 9:30pm, a bright fireball screamed over my homeland of Estonia on final approach, making a thunderous noise like artillery fire for what seemed like minutes and smashed into the Baltic Sea. Helsinki’s major newspaper Päiväleht asked for witness details and drawings to help locate the fall. As a result of Finnish citizenry’s efforts, the trajectory of the fireball was triangulated, and its impact point was determined to be in the Baltic Sea about 50 kilometers from Helsinki. Because the Baltic Sea was still frozen over in March, there was evidence of the point of impact — a three-meter hole in the surface ice. Then the recovery effort: they tried to find it by poking around with sticks, but the meteorite was 25’ down on the bedrock. So, they built a waterproof well out of wooden beams and dropped it through the hole in the ice. The well was pumped to empty out the water and mud. This did not succeed completely, but in the end a diver was able to find the fractured meteorite and pull it out. It was then displayed the following year at the World’s Fair in Paris in the Finnish pavilion. Bjurböle is a distinctive LL4 meteorite. It is unusually friable and its fine-grained creamy matrix is packed with chondrules — spherical silicate-rich droplets of fiery rain that aggregated from the dust and ice of our early solar system, before the planets formed. It also sports the catalog stamp of the Finnish Museum of Natural History (and was obtained by a meteorite trade).