Back in 2005, in this very publication, I coined the term Find2Fall to describe meteorites whose arrival on earth was not witnessed in the usual way, but it seemed obvious that the meteorite was not completely a find. For instance, there was evidence that the space rock arrived very recently, or there was a documented or historical record containing accounts that could reasonably be considered evidence of someone witnessing the events of the meteorite’s fall. But still, the binary classification of fall or find prevented notation that there might be more to the story. And for obvious reasons, science would always err on the side of caution meaning by default, everything is considered a find until proven guilty by one or more eyewitness. However…
“The Meteorite Nomenclature Committee (NomCom), which publishes The Meteoritical Bulletin on behalf of the Meteoritical Society, is mainly responsible for the oversight of meteorite names, but also documents their classifications and whether they were falls or finds.”
Categorization of Finds and Falls 24 February 2015
And thus, with the stroke of a laser printer, three more categories were created whereby a meteorite is no longer just a fall, but rather a Confirmed fall, a Probable fall, a Possible fall, or a Find, doubtful fall, or just a Find. Entries in the Meteoritical Bulletin after this 2015 ruling now contain a notation along with the find or fall designation.
And with that single sentence, the muddy waters between meteorite falls and meteorite finds become a little less murky and more nuanced especially for meteorite collectors like me. Prior to 2015, meteorites listed in the Meteoritical Bulletin were noted as either a fall or a find. But given this new set of stratified options, a meteorite falling through the roof of a television studio during a live broadcast would most likely be a confirmed fall. And a doorstop used for decades attached to a solid chunk of folklore that the stony object now blocking open the barn door once did, in fact, smash the skull of a grazing cow, well that is likely a probable fall. Especially when there is additional evidence such as fresh crust that supports the folklore. Anything less than that is a find, a find-doubtful fall, or a find-possible fall. And now, may I introduce you to the PreFall!
PreFalls are my name for space rocks that are identified prior to entering the earth’s welcoming atmosphere. Satellite and telescope technology watching the sky have identified nine such events where an incoming space rock will soon smoke its way to earth, often in full expected view of the interested locals and meteorite tourists. Now should one of those PreFalls happen to land intact on terra firma, it is not only a witnessed fall, but an anticipated confirmed fall (ACF perhaps?). And thus far, there are four of them!
2008 TC3–Ureilite
2018 LA–Howardite
2023 CX1–Ordinary Chondrite L5-6
2024 BX1–Aubrite
What makes this even more unusual, at least to me, is that of those four PreFalls where material was recovered, three or a full 75% were achondrites, and rare classes at that. While one PreFall was a L5-6 chondrite, the other three were an Aubrite, a Ureilite, and a Howardite. The chance that any single fall is an achondrite is about 8%. But Howardites fall about 1.6% of the time, Aubrites fall about 0.9%, and Ureilites a scant 0.6% of the time. I cannot see where a cause for this would be found, but I’m sure someone out there has a theory and I’d love to hear it.
The first PreFall was in October 2008 with the now famous Almahata Sitta Ureilite. The most recent PreFall was September 4, 2024, also known as last week. But there is a sleeper still out there in the form of 2022 WJ1 which fell November 19, 2022 above southern Ontario. While it’s thought the bulk of the meteorite landed in Lake Ontario. However, it is also likely some pieces fell on land and are yet to be found. According to Western News (https://news.westernu.ca/2022/11/niagara-meteor/), “Residents in the area between Port Weller and Virgil, in particular, should be on the lookout.”
So, if PreFalls become a thing and are so noted in the MetBul, then why not take it further and denote photographed falls of which there are plenty. It would be nice to have some additional information tagged on the vitals of the meteorite. Like Lost City, fall (w,p) for witnessed, photographed). Peekskill, fall (w,v) for witnessed, videoed. And Chelyabinsk (w,ltv) for witnessed, viewed live on TV). Maybe that last one is a little over the top.
In the end, two things about PreFalls stand out to me. The first is that the window of time between discovery and atmospheric impact is measured in hours, sometimes just a couple. This does not bode well for us earthlings being able to prevent a significant impact through any of our science fiction-like devices and plans. The second thing, and possibly even more concerning, is the intense euphoria in the press about these events where the incoming rocks never had the chance to pose a threat to anybody or anything often with the additional insult of “fell harmlessly into the ocean.” They report it like it’s a good thing, and it really makes me wonder whose side they’re on? Either way, future searches for meteorites might, in addition to wandering dirt and sand with magnet in hand, also include studying near-earth asteroids in hopes one will decide to make earth its home.
Until next time….
