From Heaven to Earth
My fascination with meteorites began when Jerry Armstrong, a member of the Georgia Mineral Society, showed me a specimen of Allende. This meteor exploded near Chihuahua, Mexico on February 8th, 1969 and pelted the earth with over 1,000 kg of meteorites.
Scientists have determined that Allende (pronounced ah-Yen-day) is so old it pre-dates the formation of our solar system! When Jerry told me that, the first thing I wanted to do was simply hold it in my hand. The second thing I wanted to do was own one. Jerry sold me one a few weeks later, and I’ve been hooked ever since. Just think about it: you can hold in your hand something that was flying around in space before there was Jupiter, Mars, Earth, or even our Sun! Allende has been described as “Big Bang material.” Now that’s old.
Like everything else I have collected (minerals, fossils, etc.) I started out thinking I would be happy with just one representative piece. When will I ever learn? Sure, Allende is fascinating because it’s older than dirt literally but all those other meteorites are just a bunch of black, ugly rocks right? Wrong! It turns out, they all have stories to tell, and those stories are what sets each meteorite fall apart. It’s what gives them a life of their own, a personality if you will. So, I guess I have to have them all! I’ll share my own Allende story with you in a minute.
A famous story concerns the Sylacauga, Alabama meteorite. On November 30, 1954, Mrs. Hodge was feeling a bit ill so she took to her couch in the living room. Without warning, one stone (total weight 5.56 kg) crashed through the roof of her house. It hit a radio near the couch, bounced off the radio and struck her thigh. Even though she was under a couple of blankets she still managed to come away with a whopper of a bruise because that meteorite was around eight pounds and moving fast. She became an overnight celebrity, because the odds of a meteorite striking a person are so incredibly remote. In fact, she is the only recorded case in modern history of a person being struck by a meteorite. People hounded her day and night and asked to see:
- Her bruise
- The hole in the roof
- The meteorite. (Now safely housed at the University of Alabama’s Museum of Natural History in Tuscaloosa.) Another stone was found in her yard later.
So what are meteorites? The great majority are fragments of asteroids that get knocked out of orbit from the Asteroid Belt between Jupiter and Mars. Meteorites are considered rare, but a few even more rare ones have come from Mars and our moon. Many people believe that meteorites are actually hot to the touch hours after falling to earth. This is simply not true. They can indeed be hot a few seconds later, but only the thin outer layer or “fusion crust” gets heated during its swift passage through the atmosphere. In fact, the outside layer can actually start to melt and peel back on itself, or spall off completely. This is called “ablation” and the Sikhote-Alin meteorites that fell in Maritime, Russia in 1947 are prime examples of this superheated iron effect. When you can look at a meteorite and tell the direction of its passage through space due to ablation, the specimen is said to be “oriented”. I wonder if meteorites without this feature feel disoriented?
Twenty-two separate meteorites have been found and identified in Georgia alone. This is pretty amazing in itself, because once a meteorite lands here, it doesn’t have much hope of living a long and healthy life on the ground. Our forests cover them up with leaves and our humidity quickly rusts them to the point of disintegration. I have a very small piece of “Smithsonia” from Georgia that started rusting the day it fell sometime in 1940. Today it is little more than a big stain on a cotton ball.
One of the 22 Georgia meteorites hit a mailbox in Claxton. When a meteorite hits a structure on earth (human, animal or man-made) they are called “hammers”. I have 4 hammers in my collection: “Valera” (a.k.a. The Cow Killer) which killed a cow in Venezuela, “Peekskill” which hit a parked car in New York, “New Orleans” which came through the roof of a house, and “Park Forest” which struck many man-made surfaces in Illinois. The piece I bought struck a fence, and it came with a few slivers of wood from the actual fence. One of the best places to hunt for meteorites is in a desert because they stand out black against the light brown sand and because dry conditions help preserve them. Meteorites are easy to spot on the ice in Antarctica but the environmental conditions are such that only the truly courageous or fool-hardy ever collect there. Oh, and some scientists.
Meteorites fall all over the earth, (unfortunately, vast numbers are lost in oceans and other large bodies of water) but they are almost impossible to find among rocks and debris.
Most meteorites are magnetic. Testing a specimen with a good magnet is one way to differentiate meteorites from “meteorwrongs”. Another indication is they are often heavy for their size and frequently have a black fusion crust. There are three main types of meteorites: Stony: 86% of all meteorites. They are called “chondrites” because they contain tiny spheres of silicates, or chondrules. Iron: 6% of all meteorites. These are made up of iron with a slight amount of nickel. They come from the heart of an asteroid.
Stony-Iron: 1% of all meteorites. So, why should we care about meteorites? Why study them at all? Scientists get new ideas about how the planets formed and how the universe began when they study meteorites. By knowing the radio isotopes and half-lives of certain elements, ages of meteorites can be assigned with some certainty. Comparing rocks on earth with those brought back from lunar missions has helped us understand the differences between them. Meteorites, long considered “thunderstones” or just plain oddities from the unchartered heavens, will frequently give up their secrets to those curious enough to look up to the skies and wonder. And now, back to my own Allende story. A few weeks ago I was asked to talk about meteorites at a small, local gem show. I brought my entire collection (56 specimens), my books, and my enthusiasm. I told many show attendees about my Allende and how incredibly old it was. I told how this one little piece was the catalyst that started my initial fascination with all things meteoric. When I got home and put my meteorites away, I realized that my Allende had been stolen.
I felt violated and disheartened. I sent an email to my friends at an online meteorite list serve and told them what happened. I wondered aloud why anyone would be foolish enough to put their specimens at risk again. Within hours I had offers from all over the world to replace my stolen Allende free of charge! I got offers to not only replace my Allende but was asked if I’d like a Holbrook and a Gold Basin as well? I received the most incredible outpouring of love from people I don’t even know who begged me to continue my outreach programs and not let the actions of one stupid thief put an end to it all.
The importance of educating the public about rocks, minerals, fossils and meteorites cannot be overstated. Special funding for science education is practically non-existent so it’s up to you and me to enhance a child’s education with our own knowledge and experience.
You just never know when the tiny spark you ignite in a child’s mind will become a conflagration.
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