Meteorite: Learn About Meteorites, Meteors Meteorites For Sale

Time 2020-11-10 09:03:14

Web Name: Meteorite: Learn About Meteorites, Meteors Meteorites For Sale

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A meteorite is a fragment of rock or iron from outer space, usually a meteoroid or asteroid, which survives passage through the atmosphere as a meteor to impact the surface of the Earth. Meteorites are believed to originate in the asteroid belt between the planets of Mars and Jupiter. A meteorite may range in size from less than a gram to more than 60 tons. When the path of these space rocks intersects with Earth's orbit, the meteoroid enters the atmosphere at high velocity causing the luminous phenomena we call a meteor or shooting star. These meteors should not be confused with a meteor shower. Meteor showers involve the Earth passing through a comets orbit. A very bright meteor is called a fireball and may be called a bolide if associated with a smoke train and detonations (which often produces meteorites). These events can also be tremendous force of nature. The recent Russian meteor sonic boom and shock wave on February 15, 2013 caused considerable property damage and injury to people. Sometimes the forces on these objects are too great and fragmentation will occur resulting in a few to even many thousands of individual pieces. The area on the ground surface meteorites cover is a distribution ellipse also know as a strewnfield. As the meteoroid passes through the atmosphere, ablation occurs where melting and vaporization removes material from the surface. This ablation can also produce regmaglyphs which are flight marks produced during the passage of a meteoroid through the atmosphere and often look like thumbprints pushed into the surface. This melting of the exterior surface from heating due to it's high velocity through Earth's atmosphere is also what causes the fusion crust seen on the exterior of meteorites. These factors help us with meteorite identification because the exterior features of space rocks are different from that of Earth rocks. An oriented meteorite is formed when it's passage through the atmosphere is in a stable orientation. It receives the characteristic ablation features from being melted mostly on one surface. Among these features are a rounded front surface or a cone shape and often radial lines of melting in the front surface, and a rolled over lip of melted material which has cooled around the circumference of the back side. very rare occasions large meteoroids will reach the ground with enough velocity and mass to form an impact crater. The best preserved impact crater today is Meteor Crater in Arizona. Associated with impact structures and craters is a type of rock called an impactite. This glassy rock, also called crater glass, is formed from the melting of native rocks during the impact of asteroids. A second glassy object associated with impact events but much less understood are tektites. A tektite is a natural glass object formed by the melting of native rocks during some asteroid impacts. Some tektites, the Australites, receive aerodynamic shapes as the still plastic but cooling glass falls back to the surface from very high altitude. Muong Nong tektite glass may be from a melt sheet formed near the impact site. The work done by scientists today is very different from that which was done say one hundred years ago. But, a short discussion of the history may be of some value. When a meteorite was analyzed fifty years ago or longer it was a matter of weights and measures and wet chemistry. Chondrite meteorites are [ ] I could begin and end with the simple statement that meteorites come in all sizes and all shapes and make this a very short installment indeed. Yet, that statement would nevertheless be true. Meteorites come slamming into the atmosphere and break up into nearly any shape and into pieces from dust to the largest weighing [ ] Unlike the meteorites which have been determined to have come from the Moon. Those from Mars have not had that determination made by comparing them to other actual samples. No sample return missions have yet been seen to Mars. So how do we know that Martian meteorites are truly from the Red Planet. While we [ ] Meteor Shower, Meteorite Shower six of one half a dozen of the other. Well not really. Meteor Showers are great fun to observe in the night sky as bits of comet dust the size of sand grains and small seeds scream through the upper atmosphere. But it is just a light show. Meteorite Shower refers [ ] Geoffrey Notkin of the award-winning television series Meteorite Men has written the ultimate guide to finding meteorites, METEORITE HUNTING How To Find Treasure From Space. This is a must have book for every meteorite enthusiast s library. Meteorite hunting is a challenging and often difficult activity. As with many things in life having a mentor [ ] Finding meteorites requires a lot of knowledge and a little bit of luck. Meteorites come in all sizes, shapes and types. It is a big topic, so these are just the basics. Meteorites usually have nickel-iron metal in them and will stick to a powerful rare earth magnet or set off a signal with a [ ] Looking for that unique one of a kind special gift? Have you ever thought of giving a meteorite? Come visit meteorites-for-sale.com, our online store where we make your shopping easy and secure. We ve created a How To Buy A Meteorite Guide to help you select the right meteorite for your present. Our Most Popular Meteorite [ ] We ve just listed some of the Chelyabinsk Meteorite for sale on our site.  This Russian Meteorite has secured a place in history as before February 15, 2013 there had never been a witnessed air burst explosion of an asteroid over a heavily populated area of this magnitude. The Tunguska event had more force, but there [ ] Meteorites Interest in meteorites has steadily increased overtime and the meteorites below have high public interest. This list will be updated regularly. Chelyabinsk How Many Meteorites and Where are They Found Meteorites land at random everywhere on Earth. Most land in the oceans and are not at present recovered from the water. Of those that fall on the land many are also not recovered. Meteorites often arrive in a very dramatic display with blinding light, smoke trails and thunderous detonations. The meteoroid exploding into many fragments high in the air. Meteorites can also arrive as individual pieces with less notice. In the past when there were no detection methods available many meteorites would go unrecovered. We can make estimates based on the meteorites found about how often large events occur. A handful of larger objects strike the Earth everyday. So many thousands of small ones hit the Earth that it grows heavier by tons of weight each day. While it is true that they fall randomly everywhere, they only survive for a long time if they fall in areas like deserts or places with only occasional rain. Meteorites almost universally contain iron which quickly deteriorates in the atmosphere of Earth. Meteorites which fall in jungles and forests will disappear into the ground cover and quickly fall apart by weathering likely never being recovered. The meteorites which land in deserts will fare much better. Thousands of meteorites have been recovered in the last few decades from deserts. Many of these meteorites have been on or near the surface for thousands of years. We usually think of deserts as lethally hot locations. In actual fact deserts are defined by their rain fall amount. It happens that the frozen vastness of Antarctica is also a desert by definition since it has nearly no rainfall. It is called a cold desert. Tens of thousands of meteorites have been found on the ice or found where they have been moved by the ice. Mixed with other rocks meteorites have been found in moraine deposits formed by the glaciers. Though thousands of years old freezing has preserved them from the weathering suffered by meteorites which fall in other climates. Types of Meteorites Since the first meteorites were collected and studied it has been clear that there are three basic types of meteorites. Iron Meteorites which consist of mostly iron with varying amounts of nickel. The second and most abundant group is the Stone Meteorites made up of silicate minerals with a small amount of metal grains. The third group is the Stony-Iron Meteorites which contain roughly half mineral and half nickel iron metal. Most are believed to originate from the asteroid belt but there are also meteorites proven to be from the Moon and Mars. Iron Meteorite Iron meteorites as the name states are composed of almost solid nickel-iron. Often there are mineral inclusions in iron meteorites, but they amount to a small percentage of the mass. Three main subgroups of irons have been recognized. They are the Octahedrites, the Hexahedrites and the Ataxites. The metal nickel is found in nearly all meteorites. It is the amount of nickel that was in the original bulk alloy that cooled in space that determined which of the three iron families a meteorite will be placed into. This difference in nickel chemistry results in a difference in crystalline appearance of the metal when acid etched and also determines even which nickel iron minerals will crystalize. In the Octahedrites both Taenite and Kamacite mineral crystals grow. In Hexahedrites only Kamacite can form. So Hexahedrites are essentially pure kamacite. The opposite is true with Ataxites where only Taenite was able to grow. Much more can be said about this but it is the size of the crystals in Octahedrites that determines a meteorite's placement in the next level of classification. Low nickel Octahedrites will have large crystals and are call Coarse Octahedrites, middle level nickel percentages will result in what are called Medium Octahedrites, and iron meteorites that formed where there was a higher amount of nickel will have tiny crystals and are called Fine Octahedrites. Stone Meteorite The largest group of meteorites by far is the stony meteorites. Made of minerals that for the most part are the same as minerals that are found on Earth. However,they have structures and textures not found here. The stony meteorite group is divided into two major subgroups; the chondrites and the achondrites. The chondrites get their name because of the spherical mineral structures they contain called chondrules. In space the molten droplets of rock material cooled in the very low gravity into tiny round spheres that crystallized into minerals. Achondrites are stony meteorites without chondrules. These meteorites have an igneous mineral structure with crystals that indicate they formed in an environment with some gravity. In most stony meteorites there is metallic nickel-iron. The metal is in the form of grains scattered throughout the matrix of the rock. Stony-Iron Meteorite The Stony-Iron meteorites are made of both nickel iron metal and stone and this group includes two large sub groups, the pallasites and the mesosiderites. The Pallasites are characterized by having a large portion of their mass in the form of olivine crystals with these crystals being surrounded by nickel-iron. Mesosiderites have silicate minerals found commonly in many iron meteorites but the amount of silicates gets quite high resulting in these meteorites classified as mesosiderites. Meteorites from the Moon Mars Lunar meteorites are mostly volcanic rocks called basalts. Over time the impacts on the Moon have broken the rocks into fragments that have been melted and reformed into rocks called breccias. Lunar meteorites will often show small individual areas of different colors that make up these breccias and are called clasts. Moon rocks are very old. Volcanic activity is believed to have stopped early in the Moon's history. Mars meteorites can be broken down into three distinct groups. They are Shergotty, Nakhla, and Chassigny which form a grouplet of planetary meteorites know as the SNC group. Scientists have proven that these meteorites came from Mars by comparing the trapped Martian atmosphere in the meteorites compared with the measurements of the Martan atmosphere by the NASA Viking spacecraft that landed on Mars in 1976. How To Identify a Meteorite Do you think you have found a meteorite? Many people have been to the desert, or river, or perhaps even their own backyard and found a rock that is unusual. Some of those rocks are thought to be meteorites. But how do we know? A good place to start is [...] We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites. This website uses cookies so that we can provide you with the best user experience possible. 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