PPT-Meteorites:

Introduction to methods Identification and classification EL YAZIDI Mayssa Le 31032016 Kélibia Plan Introduction Terminology Origin Identification criteria Classification. -2-Stony-Ironmeteorites are made up of about half metal and half silicates.Their composition sug-gests that theferentiated planetoids.Ironmeteorites contain mostlyFe and some Ni, and thege differentia Minerals and rocks; the composition and materials of the earth. Symmetry is key to understanding mineral structure, but needs to be. u. nderstood as something different from ‘shape’.. Some symmetry elements are permitted (and common)…. Meteorites hit the atmosphere with speeds from 12 to 72 km/. s. .. Earth’s orbital speed is 30 km/. s. and the escape speed from the solar system at the Earth is 42 km/. s. Q: draw a diagram and use it to show why the maximum speed is 72 km/. Terrestrial Ages of MeteoritesA. J. Timothy JullUniversity of Arizona The terrestrial age, or the terrestrial residence time of a meteorite, together with its exposurehistory provides us with useful i large stony meteorites, which have much lower compressive strengths than irons (Popovaet al., 2011) can survive atmospheric passage without fragmenting (Borovicka andSpurny, 2008). The best, most rece Geochronometry. Isotope tracing. History . of “primordial” . Pb. Meteorite samples . Chondrite. – a primitive, undifferentiated meteorite. CI refers to a particular class of carbonaceous . chondrite. Information for this PowerPoint obtained from: . NSTA Online Module: Solar System: . Asteroids, Comets, and Meteorites . NASA. ESA. Windows2Universe.org. This is a meteorite that had been broken off of Mars from a large impact meteorite. It spent millions of years in space before landing in Antarctica.. Comets and Their Significance. In the past, people dreaded comets as omens of human disasters such as wars or famines.. Today we know that . comets. are icy members of our solar system that have highly elliptical orbits.. Part 1 . Origin of the elements . Part 2. Geochronometry. : Age of Earth . Formation of Earth and Moon. Differentiation of core and mantle. . Isotope tracing: sequence of events. . What have we learned so far?. Leah Salditch . February 27, 2017. Mars Final Project . 3 main types of meteorites. Iron. Stony-Iron. Pallasite. Mesosiderite. Stony. Chondrites. Achondrites. Pallasite. Achondrites. Basaltic. Common, comprise ~5% of all meteorite findings . Geochronometry (methods). Nuclear synthesis. Meteorites. Age of the Earth accretion. Pb . Formation of the core . Formation of the core (energy considerations). Formation of crust. Plate tectonics starts. Asteroids. Over 100,000 asteroids.. Vesta is the largest – 330 miles. in diameter.. Size range – 330 miles to about. 100 yards.. Irregular-shaped rocky bodies.. Some asteroids have moon(s).. In recent years, meteorites have caught the imagination of scientist and collector alike. An army of people are now actively searching for them in the hot and cold deserts of Earth. Fascinating extraterrestrial rocks in meteorites are our only contact with materials from beyond the Earth-Moon system. Using well known petrologic techniques, O. Richard Norton reveals in vivid color their extraordinary external and internal structures and taking readers to the atomic level, describes the environment within the solar nebula that existed before the planets accreted. Extensively illustrated, this volume is a valuable guide to assist searchers in the field in recognizing the many classes of meteorites and it is a superb reference source for students, teachers and scientists who wish to probe deeper these amazing rocks from space. O. Richard Norton is a contributing editor for Meteorite magazine and the author of The Planetarium and Atmospherium and Rocks from Space (Mountain Press, 1998). For the last 40 years, he has taught astronomy and space sciences at various US institutions. It is said that astronomy is one of the few remaining fields in which amateurs can make a real contribution to science, and nowhere is this more true than in the field of meteors and meteorites.Although meteors are isolated and unpredictable, it is possible to predict when meteor showers - usually associated with old comets - are due they last a couple of days, during which many meteors can be observed in a single night. Equipment for watching, counting and even measuring meteors can range from the simplest (a chair) to sophisticated all-sky cameras.What is unique about meteors in astronomical observation is that many survive entry into the Earth\'s atmosphere and impact the ground - the only easily-analysed extraterrestrial material available to science.What is unique about Richard Norton\'s book is that it is both a field guide to observing meteors, and also a field guide to locating, preparing and analysing meteorites. In addition to giving the reader information about observing techniques for meteors, this book also provides a fully detailed account of the types of meteorites, how and where to find them, how to prepare and analyse them. It is thus the only complete book on the subject available at present.