Was the Tunguska Fireball a Comet Chemical Bomb?
Written by Ian O'Neill
It was an energetic event that occurred over Tunguska, but what caused it? (Don Davis)
Although there are many theories as to how the Tunguska event may have unfolded, scientists are still divided over what kind of object could have hit the Earth from space. Now a Russian scientist believes he has uncovered the best answer yet. The Earth was glanced by a large comet, that skipped off the upper atmosphere, dropping a chunk of comet material as it did so. As the comet chunk heated up as it dropped through the atmosphere, the material, packed with volatile chemicals, exploded as the biggest chemical explosion mankind had ever seen…
12,000 years ago, a large object smashed into North America, causing global destruction. Dust and ash was released into the atmosphere, triggering global cooling and possibly causing the extinction of a number of large mammals around this time. The Tunguska event was of a similar energy to that catastrophic impact, but fortunately for us, Tunguska had a benign effect on the world. It simply exploded high in the atmosphere, flattened a region of Russia and vaporized.
"Significantly, the energy of the chemical explosion is substantially lower than the kinetic energy of the body," says Edward Drobyshevski of the Russian Academy of Sciences in St Petersburg, who has published his research into the Tunguska event. The fact that the Tunguska explosion energy is lower than what is expected of the kinetic energy of an object that hit the Earth from space is key to his work. Drobyshevski therefore concludes that the event must have been caused not by an asteroid or whole comet, it was actually caused by a fragment of comet material that fell off as the main cometary body skipped off the Earth's upper atmosphere. This means that the Earth was hit on a tangent and the fragment dropped comparatively slowly toward the surface.
Sounds reasonable so far, but how did the fragment explode? Using our new understanding as to what chemicals comets contain, Drobyshevski surmises the fragment was rich in hydrogen peroxide. This is where the magic happened. The explosion was not due to a rapid release of kinetic energy, it was in fact a hydrogen peroxide bomb. As the fragment descended, it heated up. As the reactive chemicals in the material got hot, they explosively disassociated to form oxygen and water, ripping the fragment apart. The Tunguska event was therefore a huge chemical bomb and not a "regular" comet-hits-Earth impact.
An interesting study. Not content with dropping asteroids on our planet, the Universe has started throwing hydrogen peroxide explosives at us too. Whatever next?
Source: The Physics arXiv Blog
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March 27th, 2009 at 1:30 pm
Sounds nice in theory but there is no observable evidence that a comet was spotted at that time.
Even if it was a tiny comet, it should have been visible for astronomers long before it skimmed the Earth, and even if it was not visible before, the moment it skimmed Earth's atmosphere it would light up for thousands of miles visible for a lot of people and visible for many days after it moved away from Earth because of the gasses it lost that light up.
March 27th, 2009 at 2:00 pm
It is best to refer to eyewitness observation.
Sibir Newspaper, July 2, 1908:
On the 17th of June, around 9 in the AM, we observed an unusual natural occurrence. In the N Karelinski village (200 verst N of Kirensk) the peasants saw to the North-West, rather high above the horizon, some strangely bright (impossible to look at) bluish-white heavenly body, which for 10 minutes moved downwards. The body appeared as a "pipe", i.e. a cylinder. The sky was cloudless, only a small dark cloud was observed in the general direction of the bright body. It was hot and dry. As the body neared the ground (forest), the bright body seemed to smudge, and then turned into a giant billow of black smoke, and a loud knocking (not thunder) was heard, as if large stones were falling, or artillery was fired. All buildings shook. At the same time the cloud began emitting flames of uncertain shapes. All villagers were stricken with panic and took to the streets, women cried, thinking it was the end of the world.
Testimony of Chuchan of Shanyagir tribe, as recorded by I.M.Suslov in 1926:
We had a hut by the river with my brother Chekaren. We were sleeping. Suddenly we both woke up at the same time. Somebody shoved us. We heard whistling and felt strong wind. Chekaren said, 'Can you hear all those birds flying overhead?' We were both in the hut, couldn't see what was going on outside. Suddenly, I got shoved again, this time so hard I fell into the fire. I got scared. Chekaren got scared too. We started crying out for father, mother, brother, but no one answered. There was noise beyond the hut, we could hear trees falling down. Me and Chekaren got out of our sleeping bags and wanted to run out, but then the thunder struck. This was the first thunder. The Earth began to move and rock, wind hit our hut and knocked it over. My body was pushed down by sticks, but my head was in the clear. Then I saw a wonder: trees were falling, the branches were on fire, it became mighty bright, how can I say this, as if there was a second sun, my eyes were hurting, I even closed them. It was like what the Russians call lightning. And immediately there was a loud thunderclap. This was the second thunder. The morning was sunny, there were no clouds, our Sun was shining brightly as usual, and suddenly there came a second one!
Me and Chekaren had some difficulty getting under from the remains of our hut. Then we saw that above, but in a different place, there was another flash, and loud thunder came. This was the third thunder strike. Wind came again, knocked us off our feet, struck against the fallen trees.
We looked at the fallen trees, watched the tree tops get snapped off, watched the fires. Suddenly Chekaren yelled 'Look up' and pointed with his hand. I looked there and saw another flash, and it made another thunder. But the noise was less than before. This was the fourth strike, like normal thunder.
Now I remember well there was also one more thunder strike, but it was small, and somewhere far away, where the Sun goes to sleep.
Testimony of S. Semenov, as recorded by Leonid Kulik's expedition in 1930:
At breakfast time I was sitting by the house at Vanavara trading post (65 kilometres/40 miles south of the explosion), facing North. [...] I suddenly saw that directly to the North, over Onkoul's Tunguska road, the sky split in two and fire appeared high and wide over the forest (as Semenov showed, about 50 degrees up – expedition note). The split in the sky grew larger, and the entire Northern side was covered with fire. At that moment I became so hot that I couldn't bear it, as if my shirt was on fire; from the northern side, where the fire was, came strong heat. I wanted to tear off my shirt and throw it down, but then the sky shut closed, and a strong thump sounded, and I was thrown a few yards. I lost my senses for a moment, but then my wife ran out and led me to the house. After that such noise came, as if rocks were falling or cannons were firing, the earth shook, and when I was on the ground, I pressed my head down, fearing rocks would smash it. When the sky opened up, hot wind raced between the houses, like from cannons, which left traces in the ground like pathways, and it damaged some crops. Later we saw that many windows were shattered, and in the barn a part of the iron lock snapped.
March 27th, 2009 at 2:22 pm
What was wrong with the old airburst theory that posited that atmospheric pressure built up sufficiently to cause the interloper to burst in midair, creating a huge pressure wave that flattened thousands of miles of tundra forest? If a chunk of an object coming in tangentially to earth's surface were to lose a piece that eventually exploded in the air, would not the felled trees not reflect this asymmetric blast wave by having an extremely ellipsoidal blast pattern? I think Occam's razor may say otherwise.
March 27th, 2009 at 2:58 pm
If this was a fragment would we not be able to calculate where the original object would be now?
Especially if we can assume this object came out of the sun and no direct observations where possible until it was on top of the Earth.
March 27th, 2009 at 3:10 pm
As we dont know the original angle that the comet hit, and what exact direction it came from, and its mass, its almost impossible to say where it is now. Too many unknown variables.
March 27th, 2009 at 3:33 pm
Jon: Its not much of a stretch to think the scientist involved in this work hasnt thought of that, in fact it is probably one of the reasons for his work..the current Theories do not fully explain the evidence . The scientist who did this study knows more about this event ( details ) than us laypeople…he stated that he has a Theory that better explains the event than current theories. Remember this is published, *peer reviewed* work, its pretty much guaranteed that 'occams razor' has been liberally applied.
March 27th, 2009 at 3:40 pm
Oil these are witnesses of the part that fell down, not the part that skilmmed the earth and moved away after the explosion.
A comet this close to the solar system will have a tail and will be visible for many days/weeks before and after the event and seen by astronomers in a big part of the world.
March 27th, 2009 at 3:43 pm
Hasn't this claim been pretty much debunked lately? At least it comes across as distinctly non-mainstream.
March 27th, 2009 at 4:41 pm
Oillmastery- good job on digging up those eyewitnesses- I had never read those before-
There have been several good programs on the Science channel concerning the subject and the ideas are many- Meteors-comets- gas escaping from the ground out of an extinct volcano- and one scientist who still believes that it may have been an alien space ship that exploded over the area- so far no little green men have been found.
I could speculate as to what your eye witness observations conclude but I am afraid that my answers would be naive.
So lets hear it- What do you think caused the multiple explosions.
March 27th, 2009 at 5:03 pm
Nahhhh….
March 27th, 2009 at 5:17 pm
You know, this is one of the few things that could be explained by plasma and an electric jolt because of some magnetic reconnection after it has been twisten too much and snaps. LOL
March 27th, 2009 at 5:35 pm
Olaf:
As far as before goes, it is entirely possible that it's trajectory meant that from the earths perspective it was close to the sun most of the time – the perfect examples of this being most of the Kreutz Sun Grazers, and specifically, the Great Eclipse Comet of 1882 X/1882 K1).
MAny of the Kreutz sun grazers follow trajectories that, for most of the year mean their invisible – which only really leaves the question of why wasn't the parent body spotted after the collision, and I think ONE POSSIBLE explanation to this is that if it was a volatile rich fragment in a largely dusty body (which to some extent could appear to be supported by the evidence).
March 27th, 2009 at 5:55 pm
To follow up my previous post, it has been previously noted that in order for a cometary fragment to penetrate that far into the atmosphere, it would had to have been an extinct comet with a stony mantle.
What i'd like to know is if this researcher considered Lake Cheko.
March 27th, 2009 at 6:31 pm
I had thought earlier Russian researchers had identified a butterfly shaped blast pattern. Wouldn't that suggest a trajectory?
The 12,000 year old strike theory relates to the Clovis culture. See http://www.universetoday.com/2008/07/07/exploding-asteroid-theory-gains-evidence/
March 27th, 2009 at 6:58 pm
The picture accompanying this article is one of the coolest on this site in a long time.
There is so little evidence about the 1908 event that a scientist could posit just about anything that sounds remotely resonable. In cases like that, I tend toward normal explanations rather than exotic ones. A large bolide makes more sense that a molotov cocktail from space.
March 27th, 2009 at 8:15 pm
Cometary or asteroidal impact over N.A. 12,000 BCE eplains so many things its hard to ignore the possibility.
March 27th, 2009 at 10:03 pm
The event 12,000 years ago was far more severe, spreading microdiamonds over a large part of north america,
There's really no comparison. Plenty of nuclear bombs have been detonated that were far more powerful than tunguska … yet far far weaker than the event 12,000 years ago.
As for Olaf …
Not all comets are as splendid as you imagine … and in 1908, there wasn't always someone looking in the right place at the right time. The object hit around 9am in the summer … during the DAYTIME. It may not have even been visible at night!
A large primary object that dropped a fragment and skipped away is not even necessary its just another idea.
Too many people make Tunguska out to be some bizarrely mysterious thing that can't possibly be explained by anything reasonable … grow up. something entered the atmosphere. In some way it exploded in the atmosphere and may or may not have had fragments impact.
Get over it!
March 27th, 2009 at 11:58 pm
Those are some good reports Oils, I too have never read them.
I guess they really just add to the mystery surrounding this event. Nevertheless fascinating!
March 27th, 2009 at 11:59 pm
Those are some good reports Oils, I to have never read them.
I guess they really just add to the mystery surrounding this event. Nevertheless fascinating!
March 28th, 2009 at 1:39 am
What? I thought it was Hancock and his supposedly wife fighting in that region before Hancock lost his memories?
March 28th, 2009 at 2:03 am
Perhaps there has been similar events happening frequently? At least unti recent times there must have been (and is?) a good chance that scienctist could ignore such an event, since much of the earts surface are uninhabited, or has extremely few inhabitants, and science may have ignored them anyway.
March 28th, 2009 at 2:28 am
The paper by Edward Drobyshevski can be found here: http://arxiv.org/ftp/arxiv/papers/0903/0903.3309.pdf . This paper in NOT peer reviewed and has only been posted at the arXiv site, not formally published in a journal. In it Dr Drobyshevski expounds upon his "New Explosive Cosmogony" that comets originated as icy bodies (permeated with explosive hydrogen peroxide) that were ejected "in a global explosion" and include asteroids, Troyans (sic), irregular satellites, both moons of Mars & Saturn's rings. No mention of the well known Kuiper Belt or the Oort Cloud. It was supposedly hydrogen peroxide that ignited atmospherically from a chunk of a grazing comet that resulted in the Tunguska event. While he covers alternate theories of Tunguska's origin, even he admits to the difficulty in estimating the objects final trajectory, the paper itself rambles on about his NEC theory and refers to previous papers he has authored (since 1980) about it. He also ends the paper with a warning of the impending explosion of Callisto! and the subsequent bombardment of the solar system by hydrogen peroxide laced comets (see refs to two earlier papers of his in the paper above). @ Mang: Indeed, earlier researchers did identify a butterfly-shaped blast pattern at the site.
March 28th, 2009 at 2:54 am
Part of the problem here is not conflicting evidence, but the lack of evidence. We don't see the micro-diamonds, or the traces of iridium and so forth that would suggest a high Z body. The tempting assumption is that whatever it was was mostly made from carbon, oxygen, and hydrogen. However, the team that investigated the explosion wasn't very good, and tyhe ground was boggy in summer, so any hard objects may have just sunk.
We can do the same thing with the non-sighting of the comet. No-one saw a comet, though if this was a large icy body, then it ought to have a big tail. The tempting assumption is it cold not be seen because it appeared in the sky too close to the sun. That would give you an incoming vector if you want one.
Personally, I don't like this line of reasoning. It is reshaping the explanation to avoid conflicting evidence. That doesn't entirely stop it being right, but it definitely classes it as 'fringe science' for me.
March 28th, 2009 at 3:15 am
Richard Kirk:
Actually, there are traces of iridium in the bog peat at a layer corresponding with 1908, there are also Carbon and Nitrogen isotopic anomalies in this layer. Expeditions to the area in the '50s and '60s found microscopic spheres of silica and and magnetite which were enriched in Nickle – among other metals, when compared to the surrounding environment.
And then there's Reflector-T sitting in the bottom of Lake Cheko, which as I understand it, Gasperini, Bonatti and Longo are hoping to retreive or sample this year (Lake Cheko being a lake that is believed to be an impact crater from a fragment of the Tunguska bolide, and reflector T potentially being a piece of the Tunguska Bolide – the piece that caused the crater, or a fragment of it).
March 28th, 2009 at 4:37 am
The best explanation of this event i've heard is that some extraterrestrial pilot was saving mankind from destruction and he hit the asterod with his space ship, and destroyed it,
So, we are still alive because of his sacrafice.
March 28th, 2009 at 4:37 am
One wonders:
how reliable are estimates of what happened at impact events thousands, tens of thousands… millions of years ago, if it seems so difficult to get a handle on something that happened a mere century ago?
Of course, one could say that the Tunguska event was insignificant, compared to the ancient impacts we know about…. like: If it had happened 1000 years ago, would anybody even know about it – but still….. ?
March 28th, 2009 at 5:13 am
Interesting.
Jon Hanaford's summary of the Drobyshevski paper in arxiv sounds like this chap is a bit off the deep end. I can only wonder if there's going to be another 2012 website attached.
I beleive that the butterfly pattern I mentioned was reproduced in experiments to come up with the airburst theory. That means someone has a trajectory at least approximately and some estimate of error. So if that's nearly parallel to equator it could have come from sunward. If not, say it's steeply inclinded to the equator then that part's busted.
Trippy's update was interesting. I was aware of the Nickle and other elements/compounds found. I was not aware of the update on Lake Cheko and what's been found. Presumably via sonar or something like that. Does anyone have more info on that?
I wasn't aware of the multiple blasts. That gets me thinking about fragments. But I suspect that would have had to happen very near the blast point rather than something like a chain of objects entering the atmosphere.
March 28th, 2009 at 6:23 am
@ Mang: Further speculation of what may (or may not) like on the bottom of Lake Cheko can be found in the article I linked to above. Draw your own conclusions. BTW, the two refs mentioned about 'exploding Callisto' by Dr Drobyshevski are: "Jovian satellite Callisto: Possibility and consequences of its explosion" in "Earth Moon Planets" Vol. 44, pp. 7-23, 1989 and "Threat of everyday Tunguska-type events as a result of Callisto's ice envelope explosion" in "100 years since Tunguska Phenomenon: Past Present and Future" (Abstracts) Moscow pp. 175-176, 2008b. To be fair, most of his published papers could be considered 'fringe science', concerned with furthering his belief in the 'planetary origin of comets' and his 'New Explosive Cosmogony'. Just check out papers he has authored in the references section of the paper I linked to in my previous post. What a hoot! IMO this latest paper by Dr Drobyshevski is just another attempt to validate and substantiate his NEC 'paradigm'. As Ken mentioned above "Too many people make Tunguska out to be some bizarrely mysterious thing that can't possibly be explained by anything reasonable … grow up. something entered the atmosphere. In some way it exploded in the atmosphere and may or may not have had fragments impact.
Get over it!"
March 28th, 2009 at 6:49 am
@Jon/Ken I'm firmly in the something entered the atmosphere and blew up camp. It would be interesting if they can find some fragements. That might help us understand the risks going forward. Beyond that it's a historical curiosity.
March 28th, 2009 at 8:59 am
That part of the world is so remote I doubt we will ever find enough evidence to support any theory, unless a major scientific team spends some time in the area and seeks out evidence.
Interesting theory though.
March 28th, 2009 at 9:02 am
This sounds more like another Russian experment with weapons.
March 28th, 2009 at 9:20 am
Hydrogen peroxide?? Good grief! Doesn't anybody learn chemistry anymore?? How would such an object come about in the first place? And invisible to boot! This is total nonsense.
March 28th, 2009 at 9:58 am
Ken, unlike what 2012 people would believe, comets and planets do not hide behind the Sun or Moon and suddenly pops up from behind it and then decided to crashes into Earth in a few minutes or hours.
Around the orbit of Earth the sun side is lit and reaches a temperature of 100+ degree celcius, so it will boil any water and create a massive tail.
Yes it crashed during the day time but it takes days, weeks before it reaches Earth and in those time there was no light polution and people did know the stars very well.
This article explains that only a small fragment of the comet dropped to Earth the rest skimmed Earth and should create a massive tail because of the friction in the atmosphere of the part that left Earth? That would be visible for weeks in the biggest part of the world.
This theory is very unlikely in my opinion.
March 28th, 2009 at 10:07 am
If there is no evidence of the hydrogen peroxide, I wish this article never made to Universe Today. I am tired of unsupported speculation passing as science.
But if there IS evidence, this is Good News. Hydrogen peroxide can be harvested for water and O2 and a rocket fuel that is it's own oxidizer. Early U.S. spacecraft used it for attitude control. Maybe we could redirect a H2O2 rich comet or two in a place where it would be very useful – like at a construction site for an L5 colony. And the comet would supply it's own rocket fuel for the transfer.
Evidence, we need evidence I say!
March 28th, 2009 at 10:33 am
@ Mang, I whole-heartedly hope that legitimate remnants of the event can be recovered. Only then can scientists make credible statements as to the objects' origin. But considering the potential terrain, recovery of any fragments seems dim
March 28th, 2009 at 12:30 pm
After reading i think my explanation is the best. Read my post above
March 28th, 2009 at 1:00 pm
Olaf
Just think about it. Space is big.
Have you ever observed the planet Mercury? Perhaps if you have an interest in astronomy you have, but the vast majority of people have never seen Mercury.
But Mercury is in the sky every single day in full view for all of us to see all day, every day, year after year after year! …. except for the fact that the sun is very bright. Mercury's orbit is small enough that you're only ever going to see it just before sunrise or just after sunset. Planets get hidden by the sun all the time. Jupiter and Mars have been hidden in recent weeks.
The Tunguska bolide could easily have been on a trajectory that kept it's apparent angle from the sun well within Mercury's orbit.
The Tunguska bolide hit during the daytime, several hours into the daytime as it was summer, therefore it was coming from the very general direction of the sun.
The main tail of a comet generally points away from the sun, which in this case meant towards earth, preventing it from being a huge splendid fan spread across the sky.
Most comets are single-pass events that never return to the inner solar system, it was not an expected event that people were looking for.
So it was an unexpected daytime comet, near the bright sun, with it's main tail pointed towards us.
You aren't going to see that.
March 28th, 2009 at 1:07 pm
Putting aside that this guy looks very fringe or beyond.
@Olaf, while I agree these things don't hide and jump out at us. It's surprising what we miss. Several asteroids/meteors have been discovered after they passed us coming from away from the Sun. A couple were very close. Also, SOHO has found lots of sun grazing comets that we never see from Earth. So it's feasible.
Now, having said that I don't think it matters if it was a comet or a meteor. We got hit by something. Again, given the data someone should have a rough handle on the trajectory.
I think it goes beyond an alternate theory. Mineral data from the area is consistent with a meteor strike. So what's the compelling flaw in the existing theory that begs this new explanation?
Also given the speculation described in the paper. Why would I beieve it.
March 28th, 2009 at 2:00 pm
As per some of the earlier arguments, it does seem likely that if a comet were that far into the inner solar system, indeed, coming right at the Earth (ignoring a glancing blow difference), it surely would have been plainly visible to the naked eyes for, um, how many days or weeks, beforehand? Empirical evidence doesn't indicate that a comet will suddenly become visible when it is very close to the Earth.
A comet (ANY comet) that close would have been well documented, even then, in astronomical journals and newspapers. Given that the explosion happend in the daytime doesn't negate the fact that a closing comet would have been clearly visible to any skygazer during the previous nights for some period of time.
Personally, I don't believe that *any* theory involving a comet is viable.
March 28th, 2009 at 2:20 pm
@alex – again not that I think it was a comet or that it mattered. I'm not sure you would see it. I'd have to see a simulation.
Think about it. The comet dives toward the sun and comes around back towards Earth. The tail swings towards Earth and because it's sunward it is always in daylight. If we didn't see it falling towards the sun, there's a good chance we won't see it climbing away and towards us. There are lots of comets that people can't see without telescopes even at night. That's why I said it could be a comet just as well as a meteor. Now if it's a large comet, I'd expect other effects as it grew close possibly from a large tail. But then again I'd also expect a much larger boom.
Now about the bit falling off and being a chemical explosion, why do we need this? What does it explain that the existing theories don't?
March 28th, 2009 at 2:47 pm
I've read books in the past about this event=the scientist witness enough people over a 20-30 year period to have a good enough description of the trajectory before detonation. The power was about 40megatons, to compare, the US exploded a 15MT warhead and the Soviets 58MT in 1963.
It was very fortunate this event happened in a very remote, few people involved area. Lets hope the next one doesn't hit a highly populated area. The size of this object would have been impossilbe to be noticed or tracked by technology of the time, and it happened during daylight hours-today if there's an object of this size coming from the direction of the Sun and near zero albedo, it will be for all intends and purpose, not be found before detonation!!! This comet/asteroid that hit in 1908 caused more damage over a wider area than the larger 58MT Soviet warhead will do, because it was rather fragile and had a much wider air-burst
fireball because the fragments was spread out before detonation. The 58MT Soviet warhead is merely a point-blast fireball,although extemely powerful!! There are some scientist and astronomers who believes these events-whether air=burst or ground blast, may happen 1-2 times per century as we now are far more aware of the dangers and the population is much more than in 1908. These objects, should they come from the direction of the Sun and be near zero albedo, will probably not be noticed until it hits!!!! These objects, although having the potential to destroy a large city, are probably too small to find with current technology!!!!!
March 28th, 2009 at 3:31 pm
If anyone had followed the nuclear arms race between the US and the Soviet Union, it was found the hugh warheads were of deminishing returns. A 1MT warhead would destroy everything in a 4 miles (6.4KM) radius, it takes a 8MT warhead to double the radius to 8 miles (13KM) radius with 5 PoundsSquareInch(2.27KG) overpressure.
A 64MT warhead would extend the radius to 16 miles (26KM) total destruction. The large warheads are far more heavier than the smaller warheads- having 10×550kt missile will spread the pain better than a 9MT or 25MT warhead. This is why during the days before the end of the nuclear arms race, it was far better to use a 'shotgun effect' for example 8×200kt, 10×335kt etc.
To get back to the object that detonated in 1908, the blast was spead out much wider than a conventional 40MT warhead would do because in a way it did have a 'spread out' multi-warhead effect. To destroy a hugh spread out populated area, 10 500kt warheads will be more effective than a single monster 25MT warhead, besides being much more lighter payload for the missiles carrying the multi-warheads.
The arms race was crazy and I hope this crazy 'I got more bigger rock than you have' game does not start up again!!!!!!
March 28th, 2009 at 4:11 pm
Okay, so this is my second attempt at making this post.
@ Jon Hanford & Mang:
If you're interested in what's below Lake Cheko, then may I reccomend the papers written by the authors that I mentioned (as they're the authors that found it in the first place). Some how I don't think that Drobyshevski's speculations are the best place to look.
@ Stargazer & Olaf.
With respect.
First look up The Great Eclipse Comet of 1882 (formal designation X/1882 K1). The only time and place it was visible was in Egypt during a total solar eclipse.
Then look up Extinct Comets and Dormant Comets – these are comets that have lost most (but not all) of their volatiles, and/or have a thick crust that prevents them from venting volatiles and forming an observable tail or coma. I've tried posting a list of 8 objects that meet these criteria, but for some reason it doesn't want to let me.
And don't assume that I'm only pointing this out to promulgate 2012 alarmism because I'm not, I happen to think that that particularly pile is exactly that.
March 28th, 2009 at 4:33 pm
Tippy-I don't doubt many comets lost all volatiles and no longer have a tail/coma.
The object that detonated in 1908 was really not that large,just fragile. Earth is large,and there was many objects of 1908 that hit the Earths' atmosphere in the past thousand years but was not noticed or noted as they probably happened over the large Pacifc,Indian, other sparsly populated area.
I don't believe in 2012, just the fact is, these relatively small objects will hit the Earth,whether air-burst or ground and will not be seen or noticed until it detonates!!!
Lets just hope these objects don't hit a populated area.
March 28th, 2009 at 4:40 pm
Trippy, a comet only visible during solar eclips means that it is pretty far way from Earth, closer to he Sun or beyond. Such a comet does not travel in 24 hours towards Earth.
Secondly if such a comet has passed, then it will leave debris behind which we will encounter every time Earth will pass to that part of the comets orbit, so meteorite peaks will be seen every dat day. Do we have any evidence of such peak periods of falling stars?
Note I am referring what is explained in his article. It might actually have been a comet after all but that one explained in this article is highly improbable.
March 28th, 2009 at 4:56 pm
If you google- (Tunguska-Lake Cheko) – There is a ton of information from many sources. One interesting thing that I read on Wikipeda was that researchers from the Imperial College of London say that some of the trees around the lake are more than a 100 years old and this would rule out the lake having been created by a meteor or comet in 1908. Another site mentioned that aerial photos of the lake from 1938 showed trees that were more than 30 years old.
Perhaps the lake was created by an impact but at some other time in the past.
March 28th, 2009 at 5:07 pm
I have been reading a Dutch site with credible information.
Somethig moved from south to North and exploded.
For 2 days the event was visible as far as Antwerp at the horizon.
Clearly astronomers worldwide would be interested in that direction,…
Sadly enough the first expedition was 20 after the explosion.
It seems very likely that some comet came in and just exploded unlike what this article says, the complete comet fell down.
March 28th, 2009 at 5:07 pm
Layman:
I'm, aware of those objections, however if you read (for example) Gasperini's reply in 2008 to some of those objections, he makes some interesting points with regards to the trees, namely that the ones that remain that appear to be older than 1908 show evidence of having been bent over, and then undergoing a growth spurt at about the right time for 1908 – translation being that the trees around lake cheko that appear to be older than the Tunguska Event may have simply been young enough and flexible enough to survive the blast without snapping (explaining the bending) and that those that weren't were felled, letting more light onto the younger trees, explaining the growth spurt that followed.
Finally, the ground at the time was soft, peatey, and loaded with volatiles, meaning that the potential exists for a fragment to create a larger crater than would ordinarily seem to be allowed by scaling laws (or conversely, lake cheko could have been created by a fragment that was smaller than simply examining the crater size alone might indicate.
March 28th, 2009 at 5:09 pm
Layman, I pretty well understood it was a great air-burst detonation, no crater created.
The blast to the ground and the heat must have been great. I hope the next ones don't hit cities or over cities.
March 28th, 2009 at 5:25 pm
But that wasn't what I said though was it?
My point in bringing up the great eclipse comet of 1828 wasn't that. It was the fact that a great comet, comets that are exceptionally bright (Comet Hyakutake of 1996 and great Comet West of 1976 being two examples) managed to sneak into the inner solar system without being noticed.
For a start off, you're assuming that it was a periodic comet. Secondly, the debris trails do disperse over time, unless they're refreshed. Finally it was suggested in 1978 hat it could have been a fragment of Comet Encke, because the implied trajectory (implied by the blast pattern of the felled trees) is consistent with the Beta Taurid shower, AND the Tunguska Blast apparently conicided with a peak in Beta Taurid activity,
Not entirely sure how I feel about the model proposed in the article either, I suppose the only real requirement is that while the comet might have been an extinct comet (hence the lack of observable tail), that the fragment that exploded wasn't – something which is still permitted by considering an extinct comet, but were that the case, one might expect a tail to be visible after the parent body skipped out of the earths atmosphere – which only really leaves the possibility of a sungrazing comet skipping through the earths atmosphere on its inwards leg – the night glow that is so often referred to could have been (at least in part) related to the cometary tail.
March 28th, 2009 at 5:42 pm
Thanks guys- all good points and great information-Like I said there is a ton of it out there- I think that the first time that I ever read anything about Tunguska was in a popular UFO book in the early 1970's, it too was great information even if it was pseudo science-
I don't for a minute doubt that there was an explosion in 1908. On that point there is plenty of evidence. And undoubtedly, however it happened, there will be another such collision with an object from space in the future. Let’s hope that they are all small ones and that they pick out of the way destinations for there impacts.
March 28th, 2009 at 10:33 pm
I think that proposing that the Tungusta explosion could have been caused by a cometary rather than an asteroid fragment could be worth considering. To go as far as to say that a we were brushed by a larger body and this fragment fell off in the process I think is hard to believe if not proposterous. It is very likely auch a large body would have been seen and tracked even in this era. Either way this article is conjecture and not based on proof. I find it to be of little merit based on long odds against it and hardly worth taking this seriously.
March 29th, 2009 at 1:09 am
@Trippy, just a short note on your previous post. Contrary to your assertion that Comets Hyakutake and West 'snuck' into the inner solar system, both comets were discovered before their closest approach to earth and before they reached solar perihelion. Comet Hyakutake was discovered on January 30, 1996 while it was about 2 AU from the Sun. Closest approach to Earth was March 25, 1996 and perihelion occured May 1, 1996. Comet West was discovered August 10, 1975. Closest approach to Earth occured in March of 1976 and perihelion was on February 25, 1975. I was lucky enough to observe both of these comets well before their closest approach to Earth, so the assertion that these two comets 'snuck up' on us is unsubstantiated. BTW, these were really impressive sights naked eye, through binos and through telescopes, especially Comet West, as its' nucleus broke up near solar perihelion.
March 29th, 2009 at 1:11 am
oops, Comet West reached perihelion February 25, 1976.
March 29th, 2009 at 2:16 am
Nooo, it was Doctor Who that tried to save the planet that day… I wonder how he looked like in 1908
March 29th, 2009 at 3:02 am
I've never thought of the 1908 event to be more than an object that had an air-burst detonation. I do not believe there was any comet tail or whatever-the time of year in the northern hemisphere and where the luminous skyglow was seen was caused by much noctilucent clouds created by this event. The skyglow was observed at latitudes 50 degrees N and above in Europe to western Russia, the twilight is quite long at these higher latitudes compared to where I'm at in San Francisco area-the skyglow was not observed at lower latitudes like southern Europe, NW China and the Arabic countries.
During Mt Pinotubo eruption in 1991, I had a clear view to the west sunset from my home, and I saw the incredible effects caused by the eruption and the noctilucent clouds that was visible quite long after sunset, such clouds are almost not ever seen at such low latitudes 38 degrees North. I hope future hits on Earth, whether surface or air-burst is not over highly populated areas.
March 29th, 2009 at 4:52 am
I have to wonder what Drobyshevski's up to with this.
Given Checko, mineral findings, etc. the impactor could have been a rocky bit of debris from Comet Encke and link two theories together.
The whole we were grazed by a comet and a piece fell off isn't necessary and isn't supported or even suggested. And since full size comets tend to be big (think dinosaur killer sized) it just creates fear.
This really sounds like a 2012 scam without the date, website, book and media appearences. But then why publish on arvix?.
He pegs the size of the primary body as 200-500m hardly a full size comet. He does make a prediction about it
But as pointed out, the paper turns bizarre in the last paragraph of the conclusion
March 29th, 2009 at 7:18 am
Thanks to Mang and others who actually took the time to read Dr. Drobyshevski's dubious 18 page paper. One wonders why he felt compelled to publish this theory at all at the arXiv site? Although Dr. Drobyshevski is in fact 'endorsed' to post papers to this site, but submission rules clearly state:" The endorsement process is not peer review". Just a look of other papers authored by Dr. Drobyshevski in the reference section of his paper indicate a dubious approach to physics in general and his "New Explosive Cosmogony" paradigm.
March 29th, 2009 at 9:24 am
Mirror matter anyone?
Matter created in the opposing jets of a sufficiently dense gravitational well is ejected from the north and south poles and is electrodynamically spun in opposing directions.
Left handed and right handed Chirality is matter with either a right handed or left handed spin.
When the two types of matter meet, there is an instantaneous release of energy, similar to but unlike a matter/antimatter annilation.
March 29th, 2009 at 9:30 am
A Google search of 'mirror matter' will take you to several meteoric events which resemble the Tunguska event, although presumably not as large.
There is evidence for atmospheric explosions in Algeria, Australia, Jordan and now presumably over N.A. some 12,500 BCE.
Mirror matter fits the bill quite nicely.
March 29th, 2009 at 10:56 am
@Jon Hanford
That wasn't my claim though was it?
AT NO POINT did I say that Comet Hyakutake or Comet West had snuck into the inner solar system.
What I did say, however, was that the Great Eclipse Comet of 1828 snuck into the inner solar system without being observed, and that the great eclipse comet was a spectacular comet (because of it's designation as a great comet) LIKE comets Hyakutake and West.
Get it?
I was comparing the three comets in terms of visual apperance and how spectacular they were, NOT suggesting that all three snuck into the inner solar system, so that assertion is quite simply false.
March 29th, 2009 at 11:38 am
Dear Trippy, my apologies for the misunderstanding.
March 29th, 2009 at 12:30 pm
Jon.
Accepted
March 29th, 2009 at 3:21 pm
Revisiting Tunguska after 100 years is all fine and interesting, but Drobyshevski seems to be making news out of old news… I mean, it's pretty clear that Tunguska's culprit was either a comet or an asteroid, which exploded while still in the atmosphere, like many objects do explode on their path to earth. The witness accounts support the theory, as well as findings at the location. What there're no accounts for is a comet visible with naked eye during that time, so Drobyshevski's idea that Tunguska's impactor was, in fact, a part of a comet doesn't really hold the water, imho.
March 29th, 2009 at 5:41 pm
@aqua – invoking mirror matter to explain this is even stranger than what Drobyshevski has written.
@4gea – Tunguska was either a meteor or small rocky fragment of a comet. Actually it has to be fairly rocky based on mineral evidence. If it were an asteroid or a full sized coment the bang would have be far worse (please see previous comments). Also please see the many comments from others that indicate we have missed comets and major ones at that. A small piece could easily be missed even today.
Aside from Drobyshevski's strange claims at the end, what he's proposed isn't as far off the deep end as what we might think. When I went through the paper I found the "why" that he used to invoke all of this. He suggests that the explosion was too small for any of the predicted impactors. That's something that could be checked based on the numbers he and others have. I suspect the range of error in the data outweighs the thing he's trying to explain. But I haven't tried the math. That's why a peer review would be helpful.
To fix the perceived problem he suggests that the impactor came in slower than thought. To do that he proposes a fragment coming off a larger piece. The larger piece keepin most of the kinetic energy.
He also brings up discrepancies in the trajectory and suggests a turn (or rather a deflection) caused by a partial explosion. I'd never seen that before and have no idea if its necesary to explain anything.
I'm guessing he turns to the chemical part of his theory because the speed of the impactor he's suggesting may be too slow to cause the blast at all. Or maybe he's got an agenda. I'm not even going to try and figure it out.
He only jumps the couch in the very last paragraph with the whole bit about Callisto exploding.
March 29th, 2009 at 8:07 pm
Drobyshevsky is a typical crackpot believing Tunguska was seeded by exploding ices of Ganimede or Callisto and stuff like this. He has also previously `solved' the problem of dark matter:-)
Just thought I didn't want this guy to be associated with the Russian Academy of Science – despite he's working within the structure thereof.
March 30th, 2009 at 6:49 am
Every possibility has been thrown out but this one, as far as I know, but what about a small gamma ray burst??
No evidence of anything hitting the ground, though a small comet, asteroid or meteorite would vaporize. I'm just saying though…super bright light coming in, no crater or impact site left behind. The atmosphere was left glowing for days after the event. Wouldn't a gamma ray burst super charge any atoms and matter in the atmosphere to the point of luminescence?
March 30th, 2009 at 7:53 am
@ Eric Near Buffalo : A GRB related event occuring in 1908, while not positvely ruled out, would leave several unanswered questions. First question that comes to me, why no observations of a visible object in the night sky either prior to, or immediately after the event. Surely this would be a bright nighttime occurance if the GRB is within the critical 1000 l.y. distance for any Earthly damage to occur. Lighting of the nighttime( and daytime) sky would also need to be observed to fit with a GRB origin. Strong gamma radiation impinging on the Earth would not be so small and would not knock down trees for thousands of miles. A good primer on the short and long term effect of a nearby GRB & life on Earth was published today on the arXiv site & can be found here: http://arxiv.org/ftp/arxiv/papers/0903/0903.4710.pdf .This paper "Gamma Ray Bursts as a threat to Life on Earth" by BC Thomas goes into great detail on the effect of a nearby (1000 l.y.) GRB aimed at Earth covering Earth's entire lifetime, is a great read and has extensive links to relevant published papers on the matter. You might want to check it out.
March 30th, 2009 at 9:07 am
@ Jon Hanford
Thank you for your reply. I appreciate the fact that you didn't just laugh it off. I will check out that article. I did see a show a while back about Gamma Ray Bursts on the History Channel sometime at the end of last year…I believe it was a part of the channel's "Mega Disasters" series. The way they put it, a GRB would simply set the world ablaze – atmosphere and solid matter included. I only asked because I thought if it was small enough to inflict the damage it did, but did not bring about a world wide cataclysm, I thought it could be a possibility.
March 30th, 2009 at 10:04 am
I'm not buying this theory:
If it was a fragment of the comet that skimmed past Earth, then someone, somewhere must have seen the comet in the days or weeks before or after the event as it moved along in it's orbit.
Also, the comet should have had a tail, and that means debris. Where there any reports of meterors around the date of the explosion? Plus, that debris field would still exist, and we should be able to find it, along with corresponding meteor showers.
Finally, any comet that skimmed the Earth in 1908 may also be able to be tracked down, using mathematics and computer simulations. After some time, it could be narrowed down, if it's real that is.
If these things can be documented, then the theory might hold some weight. Unfortunatley, it sounds like someone is trying to bait some funding, or get his name in the press.
March 30th, 2009 at 1:43 pm
I mentioned 'mirror matter' after reading of accounts in France, Jordan and China where meteors exploded in the lower atmosphere (relative) and produced a sonic boom(s) and creating an electromagnetic pulse hot enough to fry (turn to ash) all nearby vegetation yet not leaving a crater.
In other words, complete matter to energy conversion. That would be fission right?
March 30th, 2009 at 1:49 pm
Q: What fissionable elements might otherwise explain the energy levels required for gamma ray production?
March 30th, 2009 at 1:56 pm
Fused glasses found in the deserts of Africa and Australia may prove to be remnants of mirror matter annilation events… or at least some other atmospheric fission event.
March 31st, 2009 at 9:22 am
Wow, that was some explosion. Did the flying spagetti monster drop a "bomb" from space to punish the woodland creatures of the Russian frontier? We will miss them.
April 5th, 2009 at 8:11 am
We live in an economy era, in which scientific truth is not always wanted, and not always easy to obtain from the web. Scientists talk of "eploding meteorites" for which there is no physical justification: they can break apart, or evaporate, but never explode. In the case of Tunguska (1908) it became clear during the late 90s that it was one of those rare giant outbursts of natural gas which have happened on all continents, in their cratons. More than 25 reasons contradict the infall hypothesis. Besides, infalls are some 30 times rarer than outbursts.
April 15th, 2009 at 7:02 am
After reading through the article, I just feel that I need more info. Can you share some resources please?