[meteorite-list] Happy 15th, Peekskill

From: Darren Garrison <cynapse_at_meteoritecentral.com>
Date: Tue, 09 Oct 2007 10:35:23 -0400
Message-ID: <5a4ng39vu03r3ru79d8i6d4i1u6mm6h3gb_at_4ax.com>

Just 3 years till legal! Oh, wait...

http://www.americanheritage.com/articles/web/20071009-peekskill-meteorite-astronomy-chevy-malibu.shtml

 
 
Posted Tuesday October 9, 2007 07:00 AM EDT
 


The Thing From Space That Destroyed the Car
By John Steele Gordon

Luckily for astronomers, it was a Friday night in the autumn. That meant that
hundreds of thousands of people were at high school football games, many with
camcorders at the ready to preserve any gridiron heroics. What they preserved as
well, from at least 16 different locations from Kentucky to New York, was the
path of a fireball across the sky as it streaked northeastward at better than
ten miles a second. (See videos they shot here.) As earth?s atmosphere tightened
its grip, the yard-wide meteor, which weighed several tons and shone brighter
than the full moon, broke up into at least 70 pieces. The only piece ever found
weighed about 28 pounds. It announced its arrival on planet Earth by crashing
through the back of a car parked in Peekskill, New York, on the night of October
9, 1992, 15 years ago today.

The owner of the car, a red 1980 Chevy Malibu, was 17-year-old Michelle Knapp.
She went outside with a friend to investigate the noise, and when they saw the
damage to the car, they looked beneath it and discovered the meteorite, nestled
in a small crater it had made in the driveway. It was still warm from its
passage through the atmosphere. Knapp called the police, who inspected the car
and filed a report of criminal mischief. (Given the extensive damage to the car
(see photos here), the criminal class in Peekskill must have been very
well-armed indeed for mischief to have been a plausible explanation.) The
persistent smell of gasoline from the ruptured fuel tank brought the fire
department as well. Thanks to the many videos available, astronomers were able
to calculate the angle at which the meteoroid had hit the earth?s atmosphere:
3.4 degrees. Had it been much shallower, it would have skimmed through the
atmosphere and escaped back into space. (When in space, such an object is a
meteoroid. When it enters the atmosphere and is incandescent, it becomes a
meteor. If it explodes or disintegrates in the atmosphere, it is termed a
fireball or bolide. After the pieces land, they are called meteorites.)

Astronomers were even able to determine the path that the meteoroid had taken
around the sun. For millions of years it had traveled as close as 80 million
miles from the sun, inside the earth?s orbit, and had reached out as far as
nearly 200 million miles, well beyond Mars. It had taken 1.8 earth years to
complete an orbit.

In the early days of the solar system, four billion and more years ago, the
earth was frequently bombarded with meteorites, many of them huge. The moon was
almost certainly formed by a collision between the proto-Earth and a Mars-size
object at that time. Even today, in the sedate middle age of the solar system,
earth?s considerable gravitational field sweeps up a lot of space junk as the
planet orbits the sun. Every day the earth adds many tons to its mass this way.
Most of it is in the form of dust, which simply slows up in the atmosphere
without incandescing.

But so-called ?shooting stars,? which are about the size of grains of sand, can
be seen on any clear night by the dozens from any spot on earth, if you have the
patience to wait for them. During meteor showers, such as the Perseids in August
and the Leonids in November, when the earth passes through the debris left in
the orbits of comets, they can often be seen at a rate of more than one a
minute, all seeming to come from the same point in the sky, called the radiant.
Very rarely, a meteor storm is encountered, and shooting stars can be seen by
the thousands, such as on the night of November 12 to 13, 1833, when at least a
quarter of a million shooting stars were seen over North America.

Much rarer, fortunately, are the larger hunks of space debris that are too big
to be vaporized in the upper atmosphere. These meteor falls are still
surprisingly common, however. One landed in a field in Yorkshire, England, in
1795 and narrowly missed a worker. It settled the long-standing argument about
whether stones really do fall from the sky.

In this country, a woman napping on her couch in her home in Sylacauga, Alabama,
was struck by a meteorite on November 30, 1954, when it crashed through her
roof, bounced off a radio, and hit her on the leg (see AmericanHeritage.com
article here). Houses in Wethersfield, Connecticut, were struck by meteorites
only 11 years apart, in 1971 and 1982.

Larger meteors pose graver, but exponentially rarer, dangers. The meteor that
produced the Barringer Crater in northern Arizona about 50,000 years ago was
roughly 50 yards wide and released about 2.5 megatons of energy to produce a
crater nearly a mile wide and 570 feet deep. Such a meteor strikes the earth
every thousand years or so.

The ?Tunguska event,? in 1908, was probably a comet that did not strike the
earth but rather exploded in the atmosphere over unpopulated Siberia, with a
force equal to that of a hydrogen bomb. It flattened an estimated 80 million
trees. Had its path through space been very slightly different, it might have
exploded over densely populated Europe, with catastrophic consequences.

A one-kilometer-wide meteor would cause globally devastating effects, but they
hit only every half million years or so. A six-mile-wide meteor would end
civilization and quite possibly annihilate the human race. One roughly that size
is believed to have killed off the dinosaurs 65 million years ago. There are now
programs seeking to locate major asteroids and comets with earth-crossing orbits
and develop ways of deflecting them, should they prove to be on a collision
course.

The meteorite that slammed into Michelle Knapp?s car had no such literally
earthshaking consequences. Indeed, it proved a boon to Michelle Knapp. She told
reporters that she had bought the 12-year-old car from her grandmother for only
$100, and therefore the loss was small. But meteorites have a ready market,
especially ones that achieve individual fame, often selling for thousands of
dollars. (In fact, a fragment of the Peekskill meteorite, along with some video
footage and pieces of the Malibu?s smashed taillight, will be sold at auction
later this month, with an estimated price of $2,000 to $3,000.) Knapp also sold
the old clunker of a car, which later toured the world, for enough to buy a
brand-new one.

So modest-size meteorites are invited to hit my car if they?d like to. As long
as I?m not in it at the time, of course.

?John Steele Gordon writes ?The Business of America? for American Heritage
magazine. His most recent book is An Empire of Wealth: The Epic History of
American Economic Power (HarperCollins).
Received on Tue 09 Oct 2007 10:35:23 AM PDT