This blog provides commentary on interesting geological events occurring around the world in the context of my own work. This work is, broadly, geological fluid dynamics. The events that I highlight here are those that resonate with my professional life and ideas, and my goal is to interpret them in the context of ideas I've developed in my research. The blog does not represent any particular research agenda. It is written on a personal basis and does not seek to represent the University of Illinois, where I am a professor of geology and physics. Enjoy Geology in Motion! I would be glad to be alerted to geologic events of interest to post here! I hope that this blog can provide current event materials that will make geology come alive.

Banner image is by Ludie Cochrane..

Susan Kieffer can be contacted at s1kieffer at gmail.com

Tuesday, June 14, 2011

Snakes and meteorites?

Carlos Martiez and his meteorite found on Memorial Day.
Photo from here.
The Greeley Tribune reported on Sunday that Carlos Martinez a bull-snake led Carlos Martinez to a special rock--a 4" iron meteorite shaped like a heart! He noticed his neighbors watching something in front of his house, and went out to see that a 5'-long bull snake was slithering out of his bushes.  When he looked back into his yard, he noticed the meteorite lying in a small crater in his yard.  University of Northern Colorado professor Bob Brunswig confirmed that the rock was a meteorite.

When my son was growing up, I noticed a gopher snake in our yard. Determined to show him that not all women were afraid of snakes, I gritted my teeth and reviewed my knowledge (or made up a theory) of how to pick up a snake: grab him behind the head and grab his tail.  I wasn't sure if he'd be cold and slimy or hot, but thought that I could deal with that.  What I didn't factor in was that this snake was about 4' of sheer muscle.  When I successfully grabbed him, he gave one big muscle contraction, I threw him into the air and yelled "RUN!!" So much for images...

A bit of terminology: A meteoroid is a pice of rock or ice moving through space, the term generally applied to objects smaller than asteroids. A meteor is a meteoroid that has entered the earth's atmosphere, a shooting star.  Most meteors smaller than a pea will burn up in the atmosphere due to friction with the atmosphere as the fall. A meteorite is a meteor that survives its descent.

Typical velocities of encounter with the earth are 11 km/second for objects that come in from the asteroid belt, and 51 km/second for comets.  It is likely that this small heart-shaped meteorite broke off a larger body that was entering the atmosphere and was slowed way down by friction with the atmosphere. Still, Carlos is lucky that it landed in his lawn and not in his house! The chances of a meteorite hitting a house are small, but it has happened.  In 2003 hundreds of fragments of a meteorite fell in the Park Forest area of Chicago, several fell through roofs of houses and one through the roof of a fire station.  In the same year, a 20 kg (~44 pound) stone meteorite crashed through a two-story house in New Orleans, landing in the basement.  Poor Mrs. Hodges, asleep on a couch, was hit on the hip by a 10 pound stone meteorite in 1954...and lived to tell about it!

For those who would like to learn about the types of meteorites, here's a primer.

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