Meteorites and Their Properties


I. Introduction

Eagles Nest thumbnail image

Photomicrograph of the mineral olivine in the Eagles Nest meteorite

Meteors and meteorite falls are often spellbinding, producing spectacular visual and audible effects when they occur. Meteorites, even when they are not seen to fall, are tantalizing specimens because they represent extraterrestrial material which traveled hundreds of millions of billions of kilometers, over a period of 4.5 billion years, in orbit around the sun before colliding with the Earth. Because these stones are fragments of other planetary bodies (mostly asteroids), some more primitive than the Earth, they have helped guide our search for the origin and evolution of our solar system.

Although today we understand that meteors and meteorite falls are natural consequences of solar system processes, in the past they were poorly understood phenomena, having been attributed to divine intervention by some authorities and denied by others who suspected the descriptions of falling stones were caused by mass hysteria. Because of the mystery in which meteorites were shrouded, many exaggerated stories were developed and recorded. For example, one of the earliest reports (1) states that while the people in the city of Mons, Belgium were recovering from a war in 1186, "....God chastised them again by a hail of stones which fell June 30th, whose size surpassed that of an egg and weighed more than one pound; this furious storm pushed by the wind, damaged all of the harvest, blasted the buildings (as with lightning), crushed the animals, uprooted the trees and killed a quantity of men." This report is generally considered to be a doubtful description of a meteorite shower by modern authorities (2), but it nonetheless illustrates the legendary nature of meteorite falls. In other (substantiated) cases, meteorites were considered religious objects and have been preserved in churches, monasteries, temples, shrines, and burial chambers on most continents, including North America.

Fortunately, with the benefit of many more years of study and the rapid distribution of information regarding new meteorites, meteorite falls are now recognized to be natural physical events, occurring throughout each year and all around the world. Scientists no longer question whether stones really fall from the sky, but rather realize that they provide new opportunities for scientific advancement.

People throughout the world find new samples of suspected meteoritic origin each year. It is often difficult for them to determine if their samples are really meteorites without additional information. The following information is intended to provide people with a starting point. The properties of different types of samples are outlined below. In addition, the information below explains how it is meteorites may have formed, and consequently how these samples can provide us with a unique opportunity to learn more about ancient geologic processes that have occurred in many different regions of our solar system.


(1) Prinz (1885) Les météorites tombées en Belgique et les météorites en général, Imprimerie Xavier Havermans, Bruxelles, 39 p. Translated by K. Merikangas.

(2) Graham and others (1985) Catalogue of Meteorites, University of Arizona Press, Tucson, 460 p.


Next: The origin of meteorites [En Español]

Table of Contents Button Next Section Button