Non magnetic meteorite pdf#

Chondrites contain chondrules, small spherical bodies believed to have originated during the formation of the solar nebula. 5.įigure 1-Photo of an ordinary chondrite. In etched and polished sections, many exhibit the characteristic Widmanstätten pattern of crystallization, as shown in fig. They are classified according to crystal structure and chemistry, including the percentage of nickel content. Iron meteorites are made up largely of iron-nickel alloys (fig. Pallasites, the most beautiful of meteorites, are made of olivine crystals embedded in an iron-nickel alloy (fig. Stony-irons are divided into three main groups (pallasites, mesosiderites, and lodranites) based on their mineral and metal contents. They are among the oldest objects to have formed in our solar system, estimated at about 4.5 billion years old, thus providing clues to the nature of the solar system at that time. About 82% of witnessed meteorite falls are chondrites. The most common type of stony meteorite, called a chondrite, contains chondrules, tiny mineral spherules on the scale of a millimeter or so, in a fine-grained background matrix of light-green to black minerals (figs. However, because stones resemble terrestrial rocks, especially if weathered, and irons are easier to spot and to find using metal detectors, most collections of meteorite finds are dominated by irons. Of the witnessed meteorite falls on the earth, 94.5% are stones, 4.5% are irons, and 1.0% are stony-irons (from ). Within these three main categories, meteorites are further subdivided into a number of classes. Stony-irons contain both silicates and metals in approximately equal proportions. Irons are made primarily of iron and nickel in varying proportions. Stones are similar to rocks found on the earth in that they are composed primarily of silicate minerals, that is, compounds consisting of silicon, oxygen, and various metallic elements. Meteorites are classified into three main types: stones, stony-irons, and irons. Finds were not seen to fall, but were found on the ground, often long after their arrival. A meteorite is a meteoroid that reaches the surface of the earth without being completely vaporized.įalls are meteorites whose fall to earth was witnessed and recorded, noting place and time of arrival. The term meteor is used to describe the streak of light produced when matter from space falls through the earth's atmosphere and is heated by atmospheric friction to the point of incandescence, otherwise known as a 'falling star.' Meteoroid refers to any matter in interplanetary space that is too small to be called an asteroid or comet. It also describes some common types of meteorites and discusses meteorites in Kansas. But how do you know if the rock you found is a meteorite? This publication offers some initial guidance to answer that question, or at least information to help eliminate obvious non-meteorites from consideration. The recent discovery (autumn 2005) of a 1,400-pound meteorite in Kiowa County, Kansas, spurred renewed interest in the subject for many Kansans, especially in view of the potential monetary value of some specimens.

Of the 1,530 verified meteorites from the United States (as of July 2009), 137 came from Kansas, according to the Washington University in St. Meteorites have been found all over the world, and Kansas has yielded more than its share.

Non magnetic meteorite pdf#

It's the terrestrial mineral that is most often mistaken for a meteorite in the field.Kansas Geological Survey, Public Information Circular (PIC) 26Ī complete text of this file is available as a pdf document. Be careful, as hematite (a common terrestrial iron oxide) is black, heavy for its size, and may also stick to a magnet. But most meteorite hunters use their 'meteorite cane' - a magnet glued to the bottom of a long pole or walking stick - more as a tool to pick up potential meteorites than to definitively test a specimen. A chondrite's high nickel-iron content makes it adhere to a strong magnet. For this reason, meteorite hunters often use metal detectors in areas where meteorites are likely to be found. Nickel Iron: Most chondrites contain tiny flecks of nickel iron sprinkled throughout. Over time, they can literally cause a meteorite to crumble into pieces. All this expanding and contracting can causes stress fractures to appear on a meteorite's exterior within just a few years. In summer, moisture that has worked its way into a meteorite will cause it to contract, and in winter, when frozen, it will expand. But that's not the case on Earth, where a meteorite will begin to age as soon as it hits the ground. Stress Fractures: A meteorite can exist in outer space for millions of years without experiencing corrosion. This meteorite has been cut and polished to reveal nickel-iron flecks.