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Thursday, March 29, 2018

THE SKY IS FALLING

Chicken Little is one of innumerable children's fables associated with the quote, The Sky is Falling.  In the U.S. version, an acorn is the culprit for this looming disaster.

As of five years ago, there were 170 million space debris (mostly very tiny), among 1,419 operational satellites.  There are 12 million pounds of man-made space junk out there and around 300 pieces land back on Earth every year.  I'm not sure if this was a typo, but according to Aerospace, 12 million pounds have survived the return.  Since Sputnik in 1957, there have been more than 5,000 space launches

Manned missions generally are placed in relatively low orbits, for space drag helps clear this zone of fragments.  Difficult to imagine that to stay up there, objects need to be moving at 17,000 miles per hour, about ten times the speed of a bullet.  Communication satellites are 22,236 miles away to maintain a constant Earth footprint.

China's first space station, Tiangong-1 at 19,000 pounds, was launched in 2011 into an orbit between 118 and 128 miles out, as a prototype for a larger system to be sent out in 2023.  In 2016 China lost control of this station, which will fall from the sky some time this weekend, probably on Easter Sunday 

However, while Hawaii and the rest of the USA are within the latitude band, this is not worth much of your concern, for a similar-sized piece of junk fell earlier this year and the media mostly ignored this event.  But China is a worthy villain these days.  

The calculated odds of you getting hit by debris from space is ONE IN A TRILLION.  Lightning?  One in 1.4 million.  Yet, Lottie Williams from Tulsa, Oklahoma was struck by a 6-inch long piece rocket which hit her on the shoulder on 22 January 1997.  She was not injured.

Yet, if you're paranoid, click on SATVIEW to track the path, so you can anticipate when and the landing footprint, which will extend across several hundred miles.  Here is a second link to further minimize your neurosis.

Next major casualty?  The International Space Station is wandering from 190-250 miles above the surface of Planet Earth and a crash date in the year 2028 is the current expectation.

However, the fall will be controlled, and the impact area should be in the vicinity of the Spacecraft Cemetery, 2000 miles north of Antarctica, where the ocean depth is around 2.5 miles.  More than 263 spacecraft have been purposefully crashed here since 1971.

Russia's MIR space station, all of 265,000 pounds, the largest so far, fell here in 2001.  That is a photo of MIR's remnant over the Pacific.  But the International Space Station at a million pounds will break that record, at an  embarrassing waste of $150 billion, for this is/was the highest cost object ever built, and not one major consumer product was ever manufactured on the craft.

Russia dominates, with 190 objects now resting in this cemetery, with the U.S. #2 (52) and Europe #3 (8):

How does man-made space junk compare to cosmic dust (including meteorites and such)?  It is estimated that 44 million pounds of natural stuff falls annually.  An asteroid is credited with ending the reign of the dinosaurs 66 million years ago, with the impact releasing 10 billion times as much energy as the atomic bomb over Hiroshima.  The blast was not the problem.  The darkness cooled the globe, where for two years no light reached the surface and the temperature of the planet fell by 29 degrees Fahrenheit.

But no human has yet been killed by a celestial event, although at least four have been struck by meteorites, a famous one being Ann Hodges, who in 1954 was grazed by a ten pounder while she was sleeping in bed.  While there was no permanent damage, the subsequent notoriety, led to a nervous breakdown and death at the age of 52.

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