Meteorite fragments of asteroid 2024 BX1 recovered nearby Berlin are aubrites

by

On January 21st, 2024, a small (meter-sized) asteroid now designated 2024 BX1 and detected while still in space entered the Earth’s atmosphere near Berlin (Germany). Fragments of the corresponding meteorite have now been found and determined (by Peter Jenniskens and team) to belong to the rare group of aubrites (enstatite achondrites). This meteorite will certainly have an associated orbit and will be added to the list as soon as both its name (from the MetBull DB) and orbit are officially announced.

For more info, see the press release by the SETI institute.

Santa Filomena (H5-6), Ådalen (Iron) and Al-Khadhaf (H5-6) added

by

I have added three new meteorites to the list, which now lists 49 meteorites with published orbits. Santa Filomena (Tosi et al., 2023, MAPS) is a H5-6 fallen in Brazil in 2020, which has a considerable recovered mass (80 kg). Ådalen (Kyrylenko et al., 2023, ApJ), from Sweden, is the first iron meteorite with an orbit. Unfortunately, an ownership dispute (see e.g. here: Karmaka.de), now in appeal, still stands in the way of a detailed analysis of the meteorite, inlcuding the exact type and its publication in a Meteoritical Bulletin (I’ll note here that given the soon-to-launch mission to 16 Pysche, it would be very interesting to know more about the orbits of iron meteorites). Finally, Al-Khadhaf (H5-6; MetBull 112), with a very small recovered mass (ca. 22 g), is the first meteorite found with the help of a new camera network recently installed in Oman.

New meteorites with orbits from France and Italy

by

Two recent events saw the recovery of meteorites for which there is good data on the entry fireballs: first, the fall of the small (ca. 1 m diameter) asteroid 2023 CX1 in France on February 13th, resulting in the discovery of at least 7 meteorite fragements since. Second, the fall of a meteorite on “Valentine’s day”, February 14th, in southern Italy, and the recent detection of the first meteorite fragments. I expect both events to yield meteorites with reliable orbits, in particular, the first one, which was already observed while still in space. From the look of it, both meteorites look like ordinary chondrites.

I somehow missed Ozerki (L6)

by

Many meteorites with the potential for a photographic orbit have fallen since I started this page. They all go into my candidate list, and I regularly check whether any of them have been published in the mean-time. However, the process is not perfect, as the case of Ozerki demonstrates: Ozerki is an L6 that fell in June 2018 in Russia. Its orbital elements have been published by Kartashova et al. in 2020 in Planetary and Space Science, and yet, I never stumbled over the paper. Anyway, Ozerki is in the database now. If you know of any other meteorites that I missed, please let me know.

An iron meteorite with an orbit?

by

Kyrylenko et al. report in an LPSC abstract (PDF) that they might have found the first iron meteorite with an orbit. The still unnamed, unofficial meteorite (at time of checking the MetBull database on May 24th, 2022) with a mass of 13.7 kg fell on November 7th, 2020, and seems to have a determined orbit with rough parameters of a = 1.9 AU and e = 0.5. More details are certainly forthcoming in a future publication, at which point I will include the orbit on the list.

An iron meteorite with an orbit is a very welcome and exciting addition to the suite of meteorites with orbits. Irons make out only about 4% of all falls, so “it’s about time” we have one among the 40 orbits known today. While the orbital parameters given in the abstract do not look remarkably different, over time – with more iron meteorite orbits to be expected in the future – the picture of iron meteorite origins will become much clearer. /m4

Novo Mesto EPSC abstract published

by

Vida et al. have published an abstract (PDF) to the European Planetary Science Congress (EPSC) of 2021 where they give the orbital parameters for Novo Mesto, an L5 chondrite with a photographic orbit which fell in Slovenia in February 2020. This is enough for inclusion in our list of published meteorite orbits, and a corresponding entry has been added. In total, there are now 38 meteorites with published orbital elements derived from photographic documentation.

To answer a related frequently asked question, I am aware that there are a number of recently fallen meteorites for which it is known that orbital elements were determined based on photographic documentation of the entry fireball – however, the orbital elements for these meteorite orbits are not currently available in the scientific literature because the authors chose not to add them to an abstract where they announced the publication of an orbit solution, or just haven’t published them yet in a regular journal article. If you find an abstract or article reporting orbital elements for a meteorite currently not listed, please let me know. /m4

Motopi Pan / asteroid 2018 LA

by

A new meteorite with associated orbit has been added to the table: Motopi Pan. Although officially classified as a howardite (in the MetBull database), it is a complex HED breccia with howardite, cumulate and basaltic eucrites, as well as diogenite lithologies, as the authors write in an article published online today in MAPS (Jenniskens et al., 2021). This is only the second time (the first was Almahata Sitta in 2008) that a meter-scale asteroid was found to be on a collision course with Earth only a few hours prior to impact (the asteroid was named 2018 LA), observed as a meteor when it entered the Earth’s atmosphere, and meteorites recovered afterwards, this time in Botswana. Because of the longer observation arc, the orbit is much better constrained compared to a typical “meteorite-with-orbit” fall. The orbit strongly suggests the meteoroid was delivered via the nu-6 resonance from the large asteroid Vesta. From the combination of ejection age (= cosmic-ray exposure age, ca. 22 Ma) and shock-reset age in phosphates, Jennsikens et al. (2021) even suggest that the source crater of the impact might be Rubria, in the Venenaia impact basin on Vesta.

Full disclosure: I am a co-author on the paper. /m4

Tables & Figures updated

by

The table of orbits and the three Figures (number and type of falls vs. year of fall, plane view of the solar system with all orbits, eccentricity vs. semi-major axis) have all been updated to include all 36 currently known meteorites with published photographic orbits. /m4

New paper accepted: Flensburg (C1-ungr.) in MAPS

by

A paper describing the trajectory and orbit of the Flensburg (carbonaceous, C1 ungrouped) meteorite, which fell on September 12th, 2019 in northernmost Germany, has been accepted for publication into MAPS, and the corresponding preprint uploaded on arxiv.org. The meteoroid delivering the single known piece of the Flensburg meteorite (of only 24.5 g) originates from a quite elongated orbit with a large semi-major axis (ca. 2.8 AU), which puts it right on the 5:2 orbital resonance with Jupiter, as well as in the Jupiter Family Comets field (2 < Tisserand parameter <3). It had a mass in the range of 10-20 metric tons and correspondingly, a radius of 2-3 meters. The authors suggest that based on the orbit and the very short cosmic-ray exposure age of only 7 ka (Bischoff et al., 2021), the meteoroid probably originated on a carbonaceous asteroid close to the edge of the 5:2 resonance.

Flensburg is only the fourth carbonaceous meteorite with an orbit (the others being Tagish Lake, Maribo, and Sutter’s Mill). Its interesting to note that carbonaceous meteorites are now slightly over-represented (ca. 11%) among meteorites with orbits compared to their abundance among “normal” finds (ca. 4%), perhaps because, once landed on the surface, they decay quickly and are thus less likely to be found without the “prompt” provided by the fireball observation. /m4

New paper out: Cavezzo, an anomalous L-chondrite

by

A new paper by Gardiol et al. in MNRAS (available online) summarizes the results from the initial investigation of the Cavezzo chondrite, which fell in Italy on the evening of January 1st, 2020. The meteorite, of which two fragments have been found, is an anomalous L5 chondrite, the 9th L-chondrite out of 34 meteorites with orbits. The semi-major axis and eccentricity of its parent meteoroid plot along the characteristic trend, and as is often observed, the perihelion is just inside Earth’s orbit, while the aphelion is in the asteroid belt. /m4