On January 21, 2024, a meter-sized asteroid (2024 BX1) entered Earth’s atmosphere and exploded over Berlin at 12:33 am UTC (07:45 pm EST; 04:33 pm PST).
Before reaching Earth, 2024 BX1 was a near-Earth asteroid (NEA) with an orbit that suggests it was part of the apollo group.
The fragments have since been located by a team of scientists from the Freie Universität Berlin, the Museum für Naturkunde (MfN), the German Aerospace Center (DLR), the Technische Universität Berlin and the SETI Institute and have identified them as a type rare asteroid. known as “aubritas“.
The name aubrites comes from the town of Aubrés in France, where a similar meteorite fell on September 14, 1836.
The team in charge of recovering samples of this latest meteorite was led by the meteorite astronomer from the SETI Institute Dr. Peter Jenniskens and MfN researcher Dr. Lutz Hecht. They were joined by a team of staff and students from MfN, Freie Universität Berlin, DLR and Technische Universität Berlin days after the meteor exploded in the sky.
Together, they found the meteorite fragments in fields just south of the town of Ribbeck, about 50 kilometers (31 miles) west of Berlin.
Finding the fragments was a big challenge due to the peculiar appearance of aubrites, which look like rocks like any other from afar but are quite different if you look up close.
While other types of meteors have a thin black glass crust caused by the extreme heat generated when passing through the atmosphere, aubrites have a mostly translucent glass crust. Christopher Hamann, researcher at the Museum für Naturkunde, was involved in the initial classification and participated in the search. According to what he told at a SETI Institute Press release:
“Aubrites don’t look like what people usually imagine meteorites to be. Aubrites look more like a gray granite and are composed primarily of magnesium silicates enstatite and forsterite.
It contains almost no iron and the glassy crust, which is usually a good way to recognize meteorites, looks completely different from that of most other meteorites. Therefore, aubrites are difficult to detect in the field.”
The asteroid (2024 BX1) was first discovered by Hungarian astronomer Dr. Krisztián Sárneczky using one of the telescopes at the Konkoly Observatory in budapest
The task of tracking it and predicting where it would impact Earth’s atmosphere was undertaken by NASA’s Scout mission and ESA’s Meerkat Asteroid Guard impact risk assessment systems, with JPL/Caltech’s Davide Farnocchia providing updates. frequent trajectory.
As the Chelyabinsk meteorite which exploded over southern Russia in 2013, the explosion was witnessed by many and filmed (although no damage was caused).
This was Jenniskens’ fourth guided recovery of a small asteroid that fell to Earth; previous events were a 2023 impact in France, a 2018 impact in Botswana, and a 2008 impact in Sudan. As he explained, this latest asteroid was particularly difficult to track:
“Even with the magnificent indications of meteorite astronomers, doctors Pavel Spurný, Jirí Borovicka and Lukáš Shrbený of the Astronomical Institute of the Czech Academy of Sciences, who calculated how strong winds carried the meteorites and predicted that they could be rare meteorites rich in enstatite.According to the light emitted by the fireball, our search team initially could not easily detect them on the ground.
We only discovered the meteorites after a Polish team of meteorite hunters identified the first find and were able to show us what to look for. After that, our first findings were quickly made by Freie Universität students Dominik Dieter and Cara Weihe.”
Last week, Jenniskens’ colleagues at MfN officially announced that they had performed their first analyzes of one of the meteorite fragments.
The process was led by Dr Ansgar Greshake, chief scientist of the MfN meteorite collection, which involved an electron beam microprobe studying the mineralogy and chemical composition of the fragments.
Their results revealed that the fragments are consistent with an aubrite-type achondrite meteor, which were presented to the International Nomenclature Commission of the Meteoritic Society on February 2, 2024, for verification.
“Based on this evidence, we were able to make a rough classification relatively quickly,” Greshake said. “This highlights the immense importance of the collections for research. So far, in meteorite collections around the world there is only material from eleven other observed falls of this type.”