Introduction

"To hold in your hand a piece of the solar system, a rock from space ... this is the allure of the meteorite."  O. Richard Norton -- Rocks From Space

The quote above seems to sum up the feeling of most meteorite collectors. Most of us are exposed to the idea of 'space' at a young age; in school, from books, on TV, at the movies, and any number of other places. Many of us had dreams of becoming an astronaut and traveling to distant worlds (and many of us still do!). Meteorites ARE from space, and they give us the opportunity to touch, hold, and study something from the vast unknown of space. A very popular Stone meteorite, Allende (photo at right) fell in February of 1969 in Chihuahua, Mexico. Over two tons of material has been collected from the vast strewn field.

If you are new to meteorites there are a few things that will help you on your way to becoming a meteoriticist. First of all, there are a few distinct terms to remember:

› a Meteoroid is a small object traveling through space...it could have once been part of an asteroid (most come from the asteroid belt), comet, the moon, or other planet Mars?).
› a Shooting Star occurs when a meteoroid enters the atmosphere...as the object falls, it heats up from the friction against the air and begins to burn.
› Meteor Showers occur when the dust particles from an aged comet pass through the Earth's atmosphere...these small particles zip toward the Earth and burn up creating a 'shower' of shooting stars.
› a Meteor is the bright fireball seen when a sizeable meteoroid enters the Earth's atmosphere and begins to burn...seeing one is indeed a rare occurance!
› a Meteorite is the resulting body that has traveled through the atmosphere, survived the entry, and has landed on Earth...seeing a meteorite land is extremely rare!

Types of Meteorites
All meteorites can be classified into one of the following groups:

› Stone Meteorites
› Iron Meteorites
› Stoney Iron Meteorites

The Gibeon meteorite shown at right (a slice) is a fine example of an Iron Octahedrite. This meteorite was found in Namibia in 1836.

Have You Found A Meteorite?

One of the most common questions we get here at Meteorite Central is "How do I know if what I have found is a meteorite?" Before I started collecting these cosmic wonders, I had no idea what the 'average' meteorite looked like, or how I could go about authenticating a find.

First of all there are several visual clues that most meteorites present:

 Ablation crust, or fusion crust, is the burnt covering on the outside of a meteorite and is caused by the intense heat of entering the atmosphere. Most meteorites have this crust, but some do not. If a meteor fragments into many pieces after it has traveled through the upper atmosphere, most fragments probably will not have this fusion crust. Additionally, if the meteorite has been on Earth for a long period of time, the crust can deteriorate due to weathering. The crust is usually dark in color with a glassy feel. The photo at left shows the ablated surface of the Millbillillie stone meteorite (the 'orange' look was caused by the clay-like soil the speciman was resting in for many years).

Chondrules are characteristic of the major class of stone meteorites known as chondrites. Chondrules are small crystalline spheres that range in size from a few tenths of a millimeter to a few millimeters in diameter, and are not always very easy to recognize in a specimen. The image below left is a detailed photo of El Hammami (courtesy of Tim Heitz of MidWest Meteorites) showing a large chondrule at the bottom of the section. The image below right is a detailed photo of Axtell (courtesy of Matt Morgan of Mile High Meteorites) showing multiple chondrules in a slice.

Iron content is characteristic in most meteorites. With a few exceptions, both stone meteorites and iron meteorites contain iron-nickel. A magnet is the best field tool for identifying meteorites. Many Earth rocks contain iron as well, so this test is not always certain! Because of their metallic content, many meteorites that have been on Earth for a long period of time will show rust on the surface. Many meteorite hunters attach a strong magnet to the end of a cane or pole and use this in their searching. Here is an article that Michael Blood wrote about meteorite canes.