Wednesday, December 12, 2012


As most of you are aware the world is supposed to end in a few days, according to the Mayan calendar.  Just this week, the 3-mile wide asteroid 4179 Toutatis missed us by only about 4 million miles, but it'll come by again every 4 years or so. A few months ago, the Earth had another near miss from a small asteroid the size of an aircraft carrier.  There are millions of these small asteroids careening around the Solar System.  We do get a direct hit from time to time. 

While the impact of an aircraft carrier sized asteroid wouldn't have ended life on Earth as we know it, it could have caused mayhem if it had hit a major city or caused a massive tsunami hundreds of feet high had it hit in the ocean.   The asteroid that we think wiped out the dinosaurs was about 6 miles across. 

A good example of an impact crater is the Barringer Crater near Winslow, Arizona which I've visited on two occasions.  I was standing on the corner in Winslow, Arizona and such a fine sight to see, a nickel-iron meteorite, 50 meters in diameter, barreling in at 28,600 miles per hour on top of me.  Fortunately, this event occurred about 50,000 years ago.  The impact caused rocks weighing thousands of tons to be flung for miles around the Arizona desert, and you can see them today.  The crater today is a big hole in the ground, 570 feet deep with another 700-800 feet of rubble at the bottom, almost a mile across, with walls rising an additional 150 feet above the desert floor.  

Most of the meteorite was vaporized before it hit the ground.  The crater is privately owned, and it has an informative Visitor's Center and Museum overlooking the hole.

Aside from stray asteroids, there are other things that can destroy civilization--like super volcanoes.  For example, Yellowstone Park, which is actually a huge volcanic crater, erupts every 700,000 years or so, based on the historic record.  Its past eruptions were so severe that they dramatically altered the Earth's climate and caused mass extinctions.  The fallout from the eruptions covered the whole U.S. west of the Mississippi River with several inches of volcanic ash.    If it were to erupt today, our concerns about Global Warming would go away.   The last major eruption there was about 699,000 years ago, so we still have some time.

Getting back to the Barringer Crater, a comparable event took place in 1908, but fortunately it hit a remote area of Siberia.  The year 1908 was a significant year on many counts, especially in Chicago.  It was the last hurrah of the notorious First Ward Ball (see KENSUSKINREPORT, Feb. 11, 2010), and the Cubs won the World Series for the second year in a row.  In Russia, 1908 witnessed the so-called Tunguska Event, and if it occurred 50 years later, it could have started World War III.

In what we now call the Tunguska Event, a comet or meteorite exploded 3-6 miles above the Earth's surface, in the heavily forested taiga near the Tunguska River.   It leveled an estimated 80 million trees in an area larger than the Chicago Metropolitan Area.    The explosion was as much as 1000 times more powerful than the Hiroshima atomic bomb.   If it had hit in the ocean, it would have caused a tsunami which would have destroyed many coastal cities.   Fortunately for us, it hit such a remote area that nobody was even killed.  

In fact, it was so remote that nobody bothered to investigate until 1927, nineteen years later.   Keep in mind, however, that during that time, Russia went through the destruction of World War I, the Bolshevik Revolution and Civil War.  It wasn't easy to get to the site.  You couldn't fly there, the railroad hadn't been built, and there were no roads. 

The Russian mineralogist, Leonid Kulik was instrumental in convincing the Soviet government to fund an expedition to this remote area.  He did so by convincing the commissars of the prospects of salvaging iron from the meteorite to help Soviet industry.  He had heard tales from peasants living in the vicinity, and he decided to travel there to see for himself.  He interviewed local people and found that many of the stories were exaggerated, but the truth was even more remarkable.

It hit on a sunny morning, just after 7 A.M. on June 30, 1908.  The eyewitnesses was 40 miles or more distant from the impact.   S. Semenov was sitting on his front porch in Vanavara, watching this phenomenon just before he was blown out of his chair and suffered burns from the intense heat.  His wife ran out and dragged him inside the house.  He said that he saw a column of bluish light almost as bright as the Sun, splitting the sky in two.  The split grew bigger as it moved across the sky.  A few minutes later he and others reported several "thunder strikes" as the shock wave came through. 

Another witness reported that it sounded like barrages of artillery fire.  One observer heard two strong explosions.  The ground and buildings shook, and in fact  the shock was picked up by seismic stations across Europe and Asia like in an earthquake.        The dust trails lighted up the night skies in Europe and Asia for days afterward.  Incredibly nobody was reported killed by the blast, although herds of reindeer and other animals were destroyed.

Kulik had previously studied the aforementioned Barringer Crater in Arizona, and made the determination that it was caused by a meteorite and not a volcanic eruption.  By examining soil samples and tree resin in the Tunguska area, scientists noted a very high proportion of iridium which is commonly found in extraterrestial bodies.  Scientists have found a similar proportion of iridium in the K-T Boundary, the rock layer deposited 69 million years ago when a similar impact allegedly killed off the dinosaurs. 

Astronomers disagree whether the impact was a comet or an asteroid.  Part of the difficulty is that no impact crater exists.  Whatever hit that morning exploded with such intensity that no fragments of any significant size have been found. 

Other, more creative authors have presented other possible explanations for the Tunguska Event.  Soviet writer Alexander Kazantsev wrote a science fiction account in 1946 asserting that a nuclear powered Martian spaceship blew up while attempting an Earth landing.  That book inspired others like Erich Von Daniken to write even more fanciful stories claiming the Tunguska Event was the result of a nuclear war between competing factions of aliens. 

Rupert Furneaux wrote a 1977 book in which he claimed that eye-witness reports, although ambiguous, stated that the object changed course which would suggest that it was intelligently guided.  He asserted that because it came in at approximately the same angle that today's astronauts do for re-entry, it must have been the work of space aliens.

Turner Network Television broadcasted a series called The Secret KGB UFO Files in 1998, referring to "the Russian Roswell" and claimed that the wreckage of an alien spaceship was found at the site.   This theory was also propounded by Yuri Lavbin, the President of the Tunguska Spatial Phenomenon Foundation of Krasnoyarsk.  That foundation is composed of 15 enthusiasts including geologists, chemists, physicists and mineralogists who have made frequent expeditions to the area since 1994.  Lavbin claimed, in 2004 that he found debris from an alien spacecraft--large slabs of quartz with strange inscriptions  which he described as the control panel from the spacecraft.   He brought them in for analysis, and the world has been waiting with bated breath for the results.  Perhaps the objects now reside in the Russian equivalent of Area 51. 

We have, of course the inconvenient fact that meteorite dust is present in the area.  Lavbin explains this away by asserting that the space aliens intentionally crashed into the meteorite to save the planet.  In other words, they took one for the team.

Two physicists at the University of Texas, Albert A. Jackson and Michael P. Ryan theorized, in 1973, that a small "black hole" passed through the Earth and came out the other side--in the North Atlantic.  The problem with that theory is that nobody saw the exit event and there is no evidence to indicate that.  Others have claimed that a chunk of "antimatter" fell from space and was annihilated. 

A more terrestrial origin was suggested by astrophysicist Wolfgang Kundt when he asserted that the sudden release and explosion of millions of tons of natural gas from within the Earth's crust caused the event. 

Whatever the cause, here is what we know, or at least the most widely accepted explanation, according to Dan Youmans, manager of the Near-Earth Object Office at NASA's Jet Propulsion Laboratory.   His conclusion is that the object, about 120 feet across, weighing 220 million pounds, came in at a sharp angle at 33,500 miles per hour, exploded in the atmosphere, releasing energy equivalent to about 185 Hiroshima bombs.  The friction heated the surrounding air to 44,500 degrees Fahrenheit.  The resulting shock wave projected forward and flattened the forest in a radial pattern.  Interestingly, the trees at ground zero remained standing like telephone poles although stripped of their branches and bark.  The same phenomenon occurred at Hiroshima in 1945.  There is no impact crater, but there is an abundance of cosmic material and high-nickel spherules, which is consistent with that of a meteorite.

Youmans estimated that a Tunguska size object enters the Earth's atmosphere about every 300 years on the average.  However, to set your minds at ease, although he thinks about it often, he does not stay awake at night worrying about it.  If you can't do anything about it, there's no point in worrying about it. 

And yes, your homeowner's insurance should cover it.  But if the world does end, it won't matter anyway, so don't worry.