Tunguska Explained... Again

The Tuguska event of 1908 is one of the most frequently "explained" events in recent history, trailing only the Kennedy assassination. The arXiv blog reports on the latest explanation of what knocked down all those trees without making a giant crater:

Now a new analysis by Edward Drobyshevski of the Russian Academy of Sciences in St Petersburg Russia claims to have solved these problems. Drobyshevski concludes that the object that hit in 1908 was a comet (as have many scientists before him). But unlike the others, he has been able to calculate that this comet hit the Earth's atmosphere almost at a tangent and broke apart.

The larger part of this comet skipped off the atmosphere, back into an Earth-crossing orbit (we should expect to find it nearby, predicts Drobyshevski).The smaller part rapidly heated up above Russia before exploding in the atmosphere over Tunguska.

The key to why it left so little lasting damage is the nature of the explosion, says Drobyshevski. And the key to that is our improved understanding of the chemical make up of comets. He says the comet would have had a high hydrogen peroxide content and this would have dissociated explosively as it heated up to produce oxygen and water, breaking the comet apart. It was this explosion that devastated Tunguska.

It sounds like a reasonable explanation of the event. But then, so have the last three or four, so who knows?

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tags: researchblogging.org, Tunguska event, Siberian explosion, Podkamennaya Tunguska River, Lake Cheko, planet earth, astronomy Flattened trees cover vast areas of Northeastern Siberia after the mysterious Tunguska explosion in June, 1908. Image: TASS/Sovfoto (public domain?) [larger view]. As…
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The good news is that the object that hit the earth at Tunguska 1908 was much smaller than previously thought. The bad news is that the object that hit the earth at Tunguska 1908 was much smaller than previously thought. In other words, if such a small object can do so much damage, then the…
In 1908, a huge fireball streaked across the sky and exploded a few kilometers above the Earth's surface, downing trees for miles and miles around but leaving no impact crater on the ground. This mystery was known as the Tunguska event. But how did this happen? The amount of energy released was…

Reasonable my ass. Occam's razor says that a the best explanation is aliens, since it takes so much less time to explain.

Wasn't one of those recent explanations that the offending incoming space object was ice or mostly ice? The result being that like many a good mystery novel plot, the evidence just melted away?

One Societ scientist hypothesized that the cause of the Tunguska event was an antimatter meteorite, and ended up with a small institute under his control to look for both evidence and military applications.

The blog article states:

"A similar-sized object is thought to have hit North America some 12 000 years ago, triggering the megafaunal extinction and widespread cooling."

Umm... how many people really think that? The claim received a huge amount of popular-press coverage, but much of the evidence - nanodiamonds and all - has been disputed. Just one example:

http://www.sciencedaily.com/releases/2009/01/090126173729.htm

By Emory Kimbrough (not verified) on 27 Mar 2009 #permalink

The author of this paper (E.M. Drobyshevski) has developed, over the last 30 years, an unusual theory called "New Explosive Cosmogony" in which electrical currents induced in icy moons and comets moving though magnetic fields and the solar wind electrolyze H2O ice into H2 and O2. The hydrogen and oxygen stay frozen in the ice, building up in concentration until the entire ice mass becomes a metastable high explosive that can be set off by an impact.

These ideas are not taken very seriously by the rest of the planetary science community. This is not because of establishment rejected the idea outright. Indeed, Drobyshevskiâs work appears in the more prestigious journals (Icarus, Advances in Space Research, etc.). However, has this idea proven useful to other researchers?

Iâve tracked Drobyshevskiâs publications on the ISI Web of Science http://www.isiwebofknowledge.com/ , and I cannot find a single other journal paper that cites his ideas (except for later papers by Drobyshevski himself). You can do a similar analysis using Google Scholar http://scholar.google.com/scholar?q=Drobyshevski , and youâll find a similar result: no one cites Drobyshevski but Drobyshevski.

I could only find a single NASA report from 1986 that considered, and rejected, his idea in a single paragraph:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19870004782_198700…

"Drobyshevski (1980, 1982) has proposed a method called 'volume electrolysis' whereby unipolar generator currents in icy planets such as Europa could produce large quantities of hydrogen and oxygen in the interior, which could subsequently be ignited upon meteoric impact. He suggested that over time, the buildup of the gases could be large enough that the explosions could be of near-planetary proportions and remove sufficient material to change the satellite mass significantly. If the current were limited to a value commensurate with that observed at Io the current were to pass through numerous cells in series to multiply the gas production. Drobyshevski proposes that inhomogeneities in the ice would provide these cells; although it is not obvious how such a series of cells could be produced, the current could pass around such cells rather than being forced through them. In any event, if the electric field were similar to that now present at Europa, ohmic losses in the ice should reduce the current by many orders of magnitude from that which he proposed."