Did a comet strike the Earth 12,800 years ago, causing global wildfires and starting an age of cooling? Scientists are still arguing about it. Dr. Joanne Ballard, co-author of two new papers with evidence that it did happen. Comet expert Dr. Mark Boslough says the science is flawed. I close with my own impressions of the science, the believers, and why all this matters a lot for our future. After all, the next comet strike can come at any time.

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In the second week of February 2018, two unexpected comets passed by Earth, coming closer than the moon. They mystery is: why have we NOT been hit by a large rock from space during human times? A group of scientists say there was a strike around 12,000 years ago. They claim it darkened Earth with fires on multiple continents, wiping out large animals, and kicking off a cooling period known as the Younger Dryas.

Around 2006, books were published on this comet strike, with lots of media coverage. There was also push back from other scientists, saying it never happened. Two new papers have been published in the Journal of Geology this month. The lead author in both is Wendy S. Wolbach, along with 26 other scientists.

To make the case for a climate-changing, extinction-level comet strike, just a few thousand years before the discovery of agriculture and the rise of civilization, is co-author Joanne P Ballard. Dr. Ballard is an Archaeologist for the Tennessee Valley Authority in Knoxville.

Dr. Joanne P Ballard

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Listen to or download this 28 minute Radio Ecoshock interview with Joanne Ballard in CD Quality or Lo-Fi


Listen to or download my 19 minute Radio Ecoshock interview with Mark Boslough in CD Quality or Lo-Fi



At times in this first Radio Ecoshock interview, particularly on questions involving comets or astronomy, Joanne is relaying answers from another paper co-author, the Scottish astronomer Dr. William “Bill” Napier. Napier has been publishing about possible comet strikes since 1979. Early on, with co-author Victor Clube, Napier started building a case for “coherent catastrophism.” Another proponent Duncan Steel is thought to have coined “coherent catastrophism”.

For more by Napier, see this paper: Asher, D. J.; Clube, S. V. M.; Napier, W. M.; Steel, D. I., “Coherent catastrophism”, Vistas in Astronomy, vol. 38, Issue 1, pp.1-27, 1994 (Abstract)

According to this entry in “The Velikovsky Encyclopedia”:

Coherent catastrophism is the hypothesis that the inner solar system, and consequently the Earth, has been subjected to catastrophes from passing comets. It is termed ‘coherent’ because:

“Cataclysms visit wide areas of the planet due to the coherent arrival of many impactors in a few days. It is entirely feasible that within those few days the earth could receive hundreds of blows like that of the Tunguska object.”

That second quote is from Duncan Steele. For more from Duncan, pursue Steel, D. L (1991) ‘Our asteroid-pelted planet’, Nature 354, 265 – 267 (28 November 1991). I can’t find anything beyond this title info. If anyone finds the full-text of Steel’s 1991 paper still out there on the Net, please add that link in a comment to this blog.

My point here is we are entering a current of thinking, developed by a few scientists all over the world, reconsidering the time of humans in terms of multiple comet impacts, not all of them yet known.


We will get to more recent developments in this impact hypothesis, and the new group gathered around it, in a minute. First, we have two new papers about this exact topic, published in the Journal of Geology. The first is:  “Extraordinary Biomass-Burning Episode and Impact Winter Triggered by the Younger Dryas Cosmic Impact ~12,800 Years Ago. 1. Ice Cores and Glaciers

The second is: “Extraordinary Biomass-Burning Episode and Impact Winter Triggered by the Younger Dryas Cosmic Impact ?12,800 Years Ago. 2. Lake, Marine, and Terrestrial Sediments

There are 27 authors listed on the first paper (land impacts) with many names recognized in this movement, including Firestone and West. The second paper, on Lake, Marine, and Terrestrial Sediments, has 31 authors. Both papers have Wendy S. Wolbach as lead author. But as we will see (and hear in the interview), not all listed authors are scientists with expertise in the field (most are).


Dr. Joanne P Ballard is an Archaeologist for the Tennessee Valley Authority in Knoxville, Tennessee. You can find out more about her here on Researchgate, where she says:

I analyze lacustrine sediments for charcoal, wood ash, micromorphology using thin sections, stable C and N isotopes, XRF, pollen and non-pollen palynomorphs to reconstruct fire history and vegetational and environmental changes from LGM to the Holocene.”

Joanne’s specialty in carbon dating can help pinpoint when there were major fires, even thousands of years ago. She has analyzed lakes in the southern United States, and in Michigan. Although these papers contain a graphic showing concurrent fires on many continents, including Africa and Europe, Joanne only discussed the fires in North America, where she has studied.


Joanne Ballard’s Doctoral Dissertation was also on the Younger Dryas Impact Hypothesis, titled “Evidence of Late Quaternary Fires from Charcoal and siliceous Aggregates in Lake Sediments in the Eastern U.S.A.” Joanne was originally inspired by a presentation by Richard Firestone. In this Radio Ecoshock interview she says: “I learned about this hypothesis when I attended a paleontology conference at the Mammoth Site in Hot Springs North Dakota.” The impact hypothesis offers an alternative for the usual ideas on why the great mammoths went extinct in North America. (A few mammoths persisted into historic times, as a smaller species, in Siberia). Previous to this hypothesis, the common reasons for mammoth extinction have been climate change, over-hunting by early humans, or a disease.


Proving that a comet struck the earth, a couple of thousand years before human agriculture, is easier if you have a big impact crater to show where it landed. This hypothesis is not so easy. No crater large enough for the impact effects described in this paper has been found.

The group has “evolved” ideas about the lack of a crater. In their 2006 book, “The Cycle of Cosmic Catastrophes: How a Stone-Age Comet Changed the Course of World Culture“, Richard Firestone and Allan West suggested the Younger Dryas and mammoth deaths came about due to a supernova explosion affecting Earth. Then with Napier and others, the explanation became a bit muddied, at least for untrained people. It sounds like a Comet exploded in nearby space, or on entry, and Earth then passed through a cloud of debris. That would explain the fires arising on many different continents. However, in our next interview, our other comet expert Dr. Mark Boslough says that is unlikely to impossible.

In this radio interview, Joanne Ballard suggests a comet could have hit the Laurentide Ice Sheet, then covering North America to a depth of up to two miles. The “crater” would be in ice, and so be invisible later after the melt. This is problematic when trying to explain why fires would start concurrently in Africa. Another impact proposed in the paper is a global nuclear winter from impact dust. But again, would there be that much dust from hitting the ice sheet?

Mark Boslough says a comet of the size required for the impacts in these papers would have drilled through the ice, leaving a visible crater, and being so recent, might be still steaming today!


In this interview, Joanne touches on some of the complexity of proving objects from outer space landed in a particular time zone. People are slicing up segments of “black mat” (organic goo from long ago) for microscopic work. Others have searched for irregular isotopes of rare metals coming only from comets or asteroids. When the discussion goes to “spherules” my eyes glaze over.

That is the stuff of science, and the evidence trail is beyond my abilities to judge it. Joanne also discusses using ice core data, which is generally reliable. We also discuss evidence of massive acid rain at this time.

A 2007 paper led by W.B. Masse argued that asteroids and comets have struck Earth regularly in the longer past, so why has it been so quiet during our time?


Dr. Mark Boslough

The Wiki on Mark Boslough is impressive, and so is his CV and long list of publications. Wiki says:

Mark Boslough is a physicist. He is a member of the technical staff at Sandia National Laboratories, an adjunct professor at University of New Mexico, and a Fellow of the Committee for Skeptical Inquiry.[1] Asteroid 73520 Boslough (2003 MB1) was named after him.”

However, that is out of date. Mark retired from Sandia Labs a few months ago. Now I’m just going to quote more from WIKI, because I cannot get this detail said any better:

An expert on planetary impacts and global catastrophes, Boslough’s work on airbursts challenged the conventional view of asteroid collision risk and is now widely accepted by the scientific community. He was the first scientist to suggest that the Libyan Desert Glass was formed by melting due to overhead heating from an airburst. His hypothesis was popularized by the documentaries “Tutunkhamun’s Fireball” (BBC), (recipient of Discover Magazine’s Top 100 Science Stories of 2006) and Ancient Asteroid National Geographic. which provided inspiration for the unorthodox and controversial notion that a large airburst over North America caused an abrupt climate change mass extinction.

However, Boslough has been a leading critic of the Younger Dryas impact hypothesis, arguing among other things that the proponents have misinterpreted his airburst models. He appeared as a skeptic on the “Last Extinction“ Nova, (recipient of AAAS Kavli award for best science documentary of 2009).

In 2011, he presented a paper at the IAA Planetary Defense Conference in Bucharest, Romania, in which he stated, “It is virtually certain (probability > 99%) that the next destructive NEO event will be an airburst.” This prediction proved true less than two years later, on Feb. 15, 2013, when an airburst over Chelyabinsk, Russia injured more than 1000 people. Boslough was among the first western scientists to arrive in Chelyabinsk, where he did field research and accompanied a production crew filming Meteor Strike for NOVA. Most of the documentaries are focused on his impact and airburst modeling.

In 2014, Boslough delivered a major address on “death plunge” asteroids that can pose a sudden danger to Earth at the second Starmus Festival in the Canary Islands.

So there you go. Boslough provided the original theory of asteroid airbursts, but strongly disputes the case that one happened 12,800 years ago, or that a comet of any significant size hit then either. In 2013, Boslough published an article about all this, published in PNAS, the Proceedings of the National Academy of Science. Find that article “Younger Dryas impact model confuses comet facts, defies airburst physics” here.

Boslough calls for Planetary Defense. He is the pioneer of the “airburster” space rocks (technically “bolides”) that cause significant damage, but not age-ending catastrophes. Boslough says we should worry less about big asteroids and more about smaller space debris hitting Earth.

We talk more about Mark’s book, and he tells us about the coming “Asteroid Day”.

Mark Boslough talks about the 100X Declaration

On a personal note, Mark turned a private property fight with off-roaders in Colorado into an important new argument in the climate change battle. As Mark told the Huffington Post, we have a “right to radiate”.

The right to radiate by all citizens has a much easier burden of proof. Our prescriptive easements consist of the gaps in the infrared absorption spectrum of the sky that are now being filled up by pollution. We’ve all been using them for our entire lives. And we can prove it in court if we can convince a judge that we’ve always had warm bodies, and get a physicist to be an expert witness. All we need are some real libertarians to work up some righteous indignation and file a lawsuit.


With our ability to find events from many millions of years ago, it should be easy to say whether a comet hit the Earth just before humans developed agriculture and civilization. As you have heard, it is not easy, and scientists do not agree on the results.  I spent a lot of time trying to resolve the truth about the Younger Dryas Impact Hypothesis. I did not succeed, but did find lots of worthwhile things to explore, not raised by either of our guests. Here you go from a fraction of my notes.

First, as Mark Boslough says, trust is everything in science. I checked out our guest Joanne Ballard. She went through the right training, with very good advisers at the Masters and Doctorate level. Those advisers specialized in subjects helpful to the two new papers. Joanne is a genuine scientist.

There’s a long history and deep cultural fabric running below this whole topic. Humans have long held a mythology or religious belief that matter from space drives major events on Earth. Science agrees, with a big asteroid ending the age of dinosaurs, hitting near Mexico’s Yucatan Peninsula about 66 million years ago.

The whole subject was popularized by a best-selling book published in 1950, which I read in the 1960’s: “Worlds in Collision” Immanuel Velikovsky. Then in 1979, the Scottish astronomer and author William M. Napier published, with Victor Klube, “A theory of terrestrial catastrophism“. Bill Napier is a co-author in the current paper, and provided some of the answers relating to astrophysics, relayed to us by Joanne Ballard.

Richard Firestone and Allen West joined the fray with their 2006 book “The Cycle of Cosmic Catastrophes: How a Stone-Age Comet Changed the Course of World Culture”. The science in that book has since been discounted. As you heard in our interviews, newer papers “evolved” in their theory of what happened.


There is a group of people, mostly scientists, who are dedicated to proving Comets continued to make big changes much more recently. They gather in two organizations: the Comet Research Group in the West, and the Holocene Impact Working Group based in Russia. Joanne Ballard and the other 29 authors of the new papers in Journal of Geology belong to the Comet Research Group.

The Comet Research Group was co-founded by Dr. Ted Bunch, a credible scientist; by George Howard, an enthusiast with no training in the field, and the enigmatic “Dr. Allen West”. Nobody, including science journalist Rex Dalton, has managed to find any record of science degrees for Allen West, who took up that name only recently.

I don’t have a problem with citizen scientists and enthusiasts contributing ideas and work. But we need honesty about that.  I randomly checked three “members” listed on the web site of the Comet Research Group. Dr. Sylvia Gonzalez replied she is a member, having seen evidence of a major event in her work in Mexico. Another said he is not a “member” but has written two papers supporting the hypothesis. A third denied any connection to the group.

During the interview, Mark Boslough mentioned a critical article by Rex Dalton. It’s called “Comet Theory Comes Crashing to Earth“, published May 14, 2011. Google it, or find a link in my show blog. We also mentioned the paper “The Younger Dryas impact hypothesis: A requiem” with lead author Nicholas Pinter. It was published June 20, 2011 in the journal Earth-Science Reviews.

The two new papers in Journal of Geology have about 29 co-authors. In my opinion, that is a growing disease in modern scientific literature. Science journals complain too many names are being given to add weight to a publication. There is a committee looking into this, and abuses of adding names just to help careers, with no indication who did what work. I’m not saying that happened with these two papers in Journal of Geology, but we have to recognize that a long-list of co-authors no longer guarantees anything about whether the science is correct. I was surprised when two of the co-authors here were not scientists at all.

The Comet Research Group is like a club of people with common interests in near-term impacts and coming impacts. Their Facebook page is a lively place to check out new arrivals from outer space, and research into past contacts. Everything posted there supports the Younger Dryas Impact Theory, with no criticism, but I found this Facebook page useful and I’ll be back.

The Comet Research Group is also a non-profit in the United States. The main poster on their web site is George Howard, blogger at the Cosmic Tusk. The group is doing fund-raising. They hope to raise over $100,000 to fund 3 expeditions to verify their theory. Over the past 3 months they report getting around $35,000. For example, they would like to send members to find an impact crater, perhaps in Greenland or North Dakota,.


More worrying to me, the Comet Research Group is also sending out an expedition to Jordan to investigate whether a comet destroyed the Biblical cities of Sodom and Gomorrah. It sounds like a marriage of mythology and religion, where comets determine human history. Of course that is possible, but I worry about a cult-like following developing around this subject.

“Fire from the Sky” Expedition Update ☄

Along those lines, the prolific author and amateur archaeologist Graham Hancock has endorsed the Younger Dryas Impact Hypothesis. Hancock claims there are many previous civilizations that were wiped out. This Impact Hypothesis, he says, explains what happened to them. His 2015 book “Magicians of the Gods” is based on the Hypothesis, and he gives credit to Kennett, Bunch, Allen West “and the gang”. Graham has a page promoting the Comet Research Group on his popular web site.

Comet Research Group

Getting its propers: Younger Dryas Boundary takes center stage in Fall 2015 bestseller from Graham Hancock


Hanging around the fringes of the Comet Research Group are commenters who claim the pyramids and Stone Henge are all part of human response to comet strikes. The scientists can’t be blamed for off-base comments. It’s just part of the Internet today.

George Howard and his blog the Cosmic Tusk gets “rave reviews” from the world worst climate denial blog, WattssUpWithThat. Anthony Watts has run at least three pieces on the Younger Dryas Impact Event – and why not? It wasn’t really climate change: a space rock did it! To be fair, Watts also reported on studies that refuted the Hypothesis.

Chilton Raved at Watts Up


As recently as February 2, 2018 Watts revived the theory of massive fires and the comet strike during the time of early humans. So there is a continuing traffic between some supporters of this theory and climate change denial – but no denial in the scientific papers we are considering in this show.


There is another small collection of scientists working on this theory. The Holocene Impact Working Group has six scientists “who hypothesize that meteorite impacts on Earth are more common than according to current scientific consensus.”

Although the scientists come from all over the world, the group’s server is hosted in Novosibirsk Russia, by the Tsunami Laboratory Institute, which is part of the Siberian Division Russian Academy of Sciences. That lab also maintains an “Expert Database on the Earth Impact Structures (EDEIS)”. Naturally, since global interest in the strike in Siberia in 1908, the largest in recent times, a cottage industry of scientists and tourists are fascinated by comets in Russia.

Again at the Holocene Impact site we find some books that cover “alternative history”. One example is Irishman Mike Baillie’s 1999 book “Exodus to Arthur: Catastrophic Encounters with Comets.” But I also note a Canadian book “Tsunami: The Underrated Hazard: Second Edition” by E. Bryant. Remember our space expert Mark Boslough said that a tsunami arising from a comet landing in the ocean may be possible. More research is needed, but that could be a big surprise indeed.


This seems to be a big topic for Russian research as well. I suppose that’s natural considering the big hit in Siberia in 1908, and the recent surprise strike in Chelyabinsk Russia in February 2013. The Siberian Division of the Russian Academy of Sciences holds two databases of reported hits. Co-author Bill Napier reports to Joanne Ballard that he has talked with some Russian counterparts. Of course that is natural in the global nature of science these days.

As an aside, in my darker more paranoid moments, I wonder if the Kremlin has considered a disruption war against climate science. Decarbonization is bad for the current Russian economy, which is heavily dependent on fossil fuel extraction and exports. Would they? Have they done it already, but funding scientists in the West who question climate change? I don’t think that’s an issue for the authors of these new papers, but it may come some day, or already be happening in a different venue. Watch that space.


A question I raised to Joanne Ballard in this week’s show was about another potential cause for the Younger Dryas: that a warm period caused so much meltwater that it cooled the oceans, and led to a cooling event. Some scientists worry there are early signs this is happening now, as meltwater rushing off Greenland has created a cold spot in the ocean further south.

Here is an except from a new article from Andrew Glikson: “The onset of climate tipping points: Methane and the future of the biosphere

Dr. Andrew Glikson, Australia

Andrew Glikson, Earth and paleoclimate scientist, Australian National University

As is well known to students of the history of the climate, once a temperature threshold is breached, abrupt events follow as a consequence of amplifying feedbacks, often within short time frameworks, examples being (1) stadial freeze events which followed temperature peaks during past interglacial peaks due to cooling of ocean regions adjacent to melting ice sheets, such as the north Atlantic Ocean and west Antarctica; (2) the intra-glacial Dansgaard–Oeschger (DO) ~1400 years-long warming events during the last glacial period; (3) the Younger dryas stadial freeze (12,800–11,600 years- ago) and the Laurentian stadial freeze (8200 years-ago).

In some instances it only took a temperature rise of about 1 – 2 degrees Celsius to trigger extensive ice melt, a flow of cold melt water into the oceans and thereby a regional to global freeze event, over periods ranging from a millennium to a few centuries. The abrupt transitions into and from stadial conditions could occur over a few decades and even few years.”

Oh, and by the way, check this out in Andrew’s new article:

Hudson (2011) estimates the increase in absorbed radiation due to total removal of Arctic summer sea ice as 0.7 Watt/m2, equal to about 1.05 o Celsius. This means the global effect of Arctic melting, which in itself constitutes a feedback from CO2-driven global warming, is close to the warming effect of the rise in atmospheric CO2 from 280 ppm to 407 ppm since the onset of the industrial age.”

That article by Stephen R. Hudson is here.

So, the Arctic warmed by our emissions is losing sea ice at record rates. When we have a “blue ocean” event, that will greatly increase warming all on it’s own – adding as much heating as all our emissions since the beginning of the industrial age!  I’ll be covering the big changes in the Arctic in a coming show.


So where do we end up and does it matter? I say recognizing and measuring comet impacts matters a lot. The energy released from such events are measured in terms of comparable numbers of nuclear weapons exploded. Larger rocks from outer space have already changed Earth’s climate, and caused mass extinctions. Even the smaller ones can do significant damage, as Mark Boslough told us.

Space rocks have passed close to Earth in the last few weeks. A big asteroid is expected to come very close to Earth in 2029. As Boslough said, if smaller ones come from the direction of the sun, we will not see them before impact. So more science, and raising awareness among the public is a positive thing. That’s why I did this radio program.

It is strange that we can have certainty about an event 66 million years ago, but no certain closure about a strike just 12,800 years ago. NASA still reports “the Near Earth Object (NEO) community of planetary scientists” says “that no large impacts have occurred during the past 15,000 years“. As Nicholas Pinter points out, not a single human has been proven killed by a rock arriving from outer space. Statistically, it’s been quiet on that front during our human times. How long can that last?

We need artists, and even scientists, to exercise imagination for our knowledge to progress, but we also have to be very cautious about what is science, and what is myth-making.

One of the pillars and promoters of the Younger Dryas Impact Hypothesis is a leading light of science. Dr. James Kennett from the University of California, Santa Barbara is legendary. Still, as we have seen in the case of Dr. James Lovelock, scientists with vision can sometimes be very right about one thing, and wrong about another. They may still have the same passion for both.

We are always going to be challenged by what is good science, and how we keep our imaginative minds tracking reality.  Thank you for taking this journey with me this week. I’m Alex Smith for Radio Ecoshock.

(The end music for the 1 hour show is “Path of Destruction” by Alex Smith.)


I’m asking for your support to hire a person who will help me find more radio stations, and more social media, to get these important messages out even further.  If listeners can help me raise $5,000 this program can go a lot further.  Please go to this page to lend your support. Any amount you can donate will help. Or sign up to give a small amount each month. Together, we can build this thing bigger.