Exploring abrupt climate change induced by comets and asteroids during human history

Comet fragment airburst melts, whips and freezes Chilean desert sands during Younger Dryas

Horrifying event witnessed by humans -- Brown University says desert glass is from space -- not "grass fires"

The Independent
USA Today

In the wake of Halloween last week a very, very scary scientific paper was published. “Widespread glasses generated by cometary fireballs during the late Pleistocene in the Atacama Desert, Chile,” Shultz et al.”(October, 2021) creates a rebuttable presumption that horrific cosmic airbursts — without leaving craters — have indeed occurred in human history, a decade long contention here at the Tusk.

The chilling part is that evidence for this type of atmospheric hell storm can be difficult to detect, and therefore we have no idea how often they occur. If the explosions didn’t happen in the last 300 years or so, like Tunguska, it is unlikely they would be “recorded,” except as wild sounding myth, oral traditions of illiterate villagers, and spiritual recollections.

And again, like Tunguska, within a few generations there would not be anything more than microscopic evidence at the location of the blast. But fortunately, the special conditions of the Atacama Desert, and other deserts, reveal evidence of fire from the sky more easily than in say…Ohio.

Shultz et al. provides yet more physical evidence that Planet Earth and humans have encountered showers of fragile comet debris that impact the atmosphere — but do not ding the earth itself. Kinda like bridge jumpers who don’t deform the river bottom, but do find a very hard, energetic stop on the way down.

Due to the extreme change in density from outer space to air, a whole class of incoming debris — the vast majority — never dig a hole. They just blow up in the atmosphere and create ferocious blasts exceeding the most awful nukes ever devised. And, like nuclear bombs, depending on the altitude of the blast (and in the case of space debris, the angle of entry) they don’t leave behind craters.

To make matters worse, they also come in swarms:

The distribution and general similarity of glasses with the same entrained meteoritic clasts at widely separated locations require either successive low-altitude breakup of a single body with a low-angle trajectory or a series of tidally disrupted bodies entering the atmosphere at relatively high angles (>30° from the horizontal), analogous to the Shoemaker-Levy 9 collision by a fragmented cometary body on Jupiter. ~Shultz, 2021

The paper puts the date of the Chilean hellstorm at 12,500, which is notable to the Tusk because it is very close to the YD impact and climate crash date of ~12,800. A 2.4% discrepancy is good enough for government work, you might say. But it also provokes my suspicion that Pete Shultz could be dead right on the date, and we are seeing evidence supporting the work of Clube and Napier.

To wit: The Taurid meteor stream presents repeated threats, which wax and wane through the millennia since a giant comet entered our solar and began disintegrating ~20,000 years ago.

As Bill Napier put it to me, its like highway traffic. Depending on the time of the day — or portion of millenia/or given span of time — you can have very busy periods where crossing the highway (blindfolded as we are) is deadly from a thousand points, and others where you could more likely cross safely. It’s a chaotic state with some elements of predictability. Current impact frequency analysis by NASA and others consider the highway to be equally busy at all times of the day, year round, for millennia.

So the Younger Dryas encounter can be thought of as a very bad stretch of traffic — obviously with some trucks — which may have been preceded and followed by pulses of lesser events within hundreds of years.

I’m left to wonder if Shultz et al. somehow managed to have this profound paper published in the week of “peak traffic” for the Taurid Stream, in late October/early November. That would be creepily fitting, since Halloween appears to be a cultural artifact of the repeated fall traumas.

Our results have three important implications. First, the Pica glasses illustrate the difficulty in recognizing such [airburst] events due to the poor geologic expression at the time of formation, the soil conditions necessary for glass generation, and the low preservation potential. Consequently, these glasses provide a unique, well-preserved recent record that can be used to constrain details about the formation process and the frequency of similar airbursts. Second, the dates for the Pica glasses coincide with the disappearance of Qua-ternary megafauna in South America, an extinction that was more severe than that on any other continent (Barnosky and Lindsey, 2010). While a direct causal link is not claimed, the timing is intriguing. Third, the entrained mineral assemblages are most consistent with a cometary body. Recent studies suggest that more than 16% of the objects >3 km in diameter hitting Earth may be cometary (Quintana and Schultz, 2019), which is higher than some previous estimates (e.g., Weiss-man, 2007). Such an airburst would affect a much broader area than a cratering event (for an equivalent-mass object), as demonstrated by the numerous airburst scours on Venus (e.g., Schultz, 1992) and entry models for Earth (Boslough, 2014)


6 Responses

  1. A corollary hypothesis to the Mid Pleistocene Transition Impact holds that the 600 km long and 100 km wide traverse of a comet on a grazing regime trajectory through kilometers of MIS 20 continental ice sheet and Michigan Basin late Paleozoic sediments created the Saginaw Glacial “lobe” footprint as its distinctive astrobleme; the Carolina Bays, Rainwater basins and High Plains Playas as dimples in density waves of hydrated sediments spreading across the landscape of North America; and the Australasian Tektites as distal ejecta. Oh, and allowing for a significant portion of the now-shattered comet to continue on its merry way on an earth-crossing heliocentric orbit. I’m implying that the Taurid Stream has evolved over 800,000 years, but we are speaking of “geological weeks” for events that are functioning across 4 billion years of planetary accretion through cosmic impacts. Dr. Napier told me a decade ago that the Taurid Progenitor did not need to actually impact Earth to cause the comet to break up, but just 788,000 years ago the Earth DID suffer its largest cosmic impact of the past 30 Million years. The impact site remains “missing” after 50 years of searching the wrong side of the Earth.

  2. Thank you, Mr. Howard, for sharing these reports.

    It’s worth recalling that the US military some decades past created and may yet maintain a world-wide network of “listening posts” –– i.e., some fairly sensitive but durable microphone stations, including anchored mid-oceanic buoy platforms, if memory serves. These were intended initially to monitor possible violations of treaties ending atmospheric nuclear testing. Over the years there have been a number of reports of detonations over remote portions of the oceans, that at first were thought to be possible illicit Nuclear Weapons Tests.

    But subsequent investigations found Zero evidence of radioactive fission products that are almost impossible to conceal/contain/mask. The reports surmised that what had been detected were fairly substantial cometary or asteroidal fragments that exploded in the upper atmosphere over the trackless oceans…out of sight of land observers, and of ships’ crews plying their assigned routes.

    Evidently, the incidence of enormous extraterrestrial bodies ‘sploding in our atmosphere is far more common than we have supposed. It is a little daunting to imagine the detonations that were thought to be NUKES… Guess we should be thankful for those big wide oceans.

  3. Thanks for posting this, George. Keeping up like this in a timely fashion is good.

    I am an airburst skeptic. Since Chelyabinsk in 2013, airbursts are the cosmic toy of the day. Even though Chelyabinsk’s flare up is called an explosion, I don’t agree. It broke up at about 25km elevation and the shock waves from that and its exposing of lots more surface area to the air resistance which heats up the rock, that knocked down one building and caused some February sunburn-type effects.

    Given how fast they travel (15-20 kps) and the typical 15-20° downslope of their paths, doing damage like turning desert sand into glass means a very close encounter. As we saw in Chelyabinsk, the time to hit the ground was only 30 seconds or so from a height of 25 kms. That means the time in any 100 meter height slice of the atmosphere while it was dropping the equivalent of dropping 50kms in a minute. Or 1.2 kms per second.

    I am flabbergasted that anyone can think that it is in the airburst ‘zone’ at the magic height necessary to melt glass.

    Our friend Boslough drew the same magical conclusion about the Egyptian Desert Glass, around ten years ago, and he even drew up a program that fitted his magical numbers. And he got some magical results.

    If this is in any way different from Boslogh’s dream, can somebody tell me why it is better? Bos let his ego get in the way. Peter Schultz I don’t think does that. But I disagree that such a thing is at all likely – to match the height and the airburst dynamic pressures and temps. If they happen 2 kms higher or not at all, the window of time for the sand melting to happen before actual impact happens is simply not within statistical possibilities, IMHO. Magical airbursts I don’t get into. They happen at the end of most every shooting star – but way up near the top of the atmosphere.

    Anything big enough to melt out dozens of kms away isn’t going to melt equally all that way out to the edge.

  4. Interesting stuff George. But I notice that folks are still too naive, thinking in terms of a single, one fragment at a time event.
    During the early phases of the Taurid progenitor’s breakup there would have been the potential for something orders of magnitude more violent.
    If you can imagine what a few hundred barge loads of gravel, rocks, and ice might do coming in and filling the sky with I can show you where something like that must have hit right here in California. And these burnt, partially melted, and thermal fractured, rocks look like they were freshly roasted just last year.

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