This preview shows page 1-2-3-4-5-6-7-8-9-10-11-12-83-84-85-86-87-88-89-90-91-92-93-94-168-169-170-171-172-173-174-175-176-177-178-179 out of 179 pages.
Astronomy 101The Solar SystemTuesday, Wednesday, ThursdayTom [email protected] 101The Solar SystemTuesday, Wednesday, ThursdayTom [email protected] Schedule• Today –Quiz; Meteorites, Mercury, and Venus• Wednesday -Presentations•Thursday -Mars•Thursday -Mars• Tuesday –Last quiz; Optional final; Final presentationRemaining ScheduleQuiz; Meteorites, Mercury, and VenusPresentationsLast quiz; Optional final; Final presentationWhat are meteorites?What are meteorites?Meteorite•A small extraterrestrial body that reaches the Earth's surfaceMeteoriteA small extraterrestrial body that reaches the Earth'sWhy are meteorites important?Why are meteorites important?Why are meteorites important?•They are primarily fragments of asteroids, which can hit us•They are records of the early solar system•They are records of the early solar systemWhy are meteorites important?They are primarily fragments of asteroids, which They are records of the early solar systemThey are records of the early solar systemMoonMoonMeteorites•Usually have ages of ~4.6 billion years•Asteroids and comets are thought to be the building blocks of the terrestrial planetsbuilding blocks of the terrestrial planetsMeteoritesUsually have ages of ~4.6 billion yearsAsteroids and comets are thought to be the building blocks of the terrestrial planetsbuilding blocks of the terrestrial planetsMeteorites•Many early cultures recognized (or believed) certain stones as having fallen from the sky•Many early cultures had tools made from iron •Many early cultures had tools made from iron meteorites•But to the scientists of the Renaissance and later periods, stones falling from the heavens were considered superstition or heresyMeteoritesMany early cultures recognized (or believed) certain stones as having fallen from the skyMany early cultures had tools made from iron Many early cultures had tools made from iron But to the scientists of the Renaissance and later periods, stones falling from the heavens were considered superstition or heresyMore evidence …•In 1492, a meteorite weighing almost 130 kilograms landed near the town of Ensisheim, Alsace, France, then in the hands of GermanyAlsace, France, then in the hands of GermanyMore evidence …In 1492, a meteorite weighing almost 130 kilograms landed near the town of Ensisheim, Alsace, France, then in the hands of GermanyAlsace, France, then in the hands of GermanyThen ..•In 1794, Ernst Friedrich Chladni, considered the father of meteoritics, published a book in which he concluded that stone and iron masses did fall he concluded that stone and iron masses did fall out of the sky•In 1803, thousands of meteorite fragments bombarded L'Aigle in Normandy, France, an event investigated by JeanFrench Academy of Science. Then ..In 1794, Ernst Friedrich Chladni, considered the father of meteoritics, published a book in which he concluded that stone and iron masses did fall he concluded that stone and iron masses did fall In 1803, thousands of meteorite fragments bombarded L'Aigle in Normandy, France, an event investigated by Jean-Baptiste Biot of the French Academy of Science.Thomas Jefferson•Meteorite landed in Weston, CT•It was brought to Yale where it was concluded it was from outer spacewas from outer space•Thomas Jefferson, President of the United states, was told about itThomas JeffersonMeteorite landed in Weston, CTIt was brought to Yale where it was concluded it Thomas Jefferson, President of the United states,And responded•"Gentlemen, I would rather believe that two Yankee professors would lie than believe that stones fall from heaven."stones fall from heaven."And responded"Gentlemen, I would rather believe that two Yankee professors would lie than believe that stones fall from heaven."stones fall from heaven."Meteorites•Named after a nearby geographic localityMeteoritesNamed after a nearby geographic localityMeteorite• Esquel Pallasite•Found in Esquel, ArgentinaMeteoriteFound in Esquel, ArgentinaMeteorites•Almost all are thought to be fragments of asteroids•Where else can they come from?MeteoritesAlmost all are thought to be fragments of asteroidsWhere else can they come from?Meteorites•Almost all are thought to be fragments of asteroids•Where else can they come from?–Moon -~68 samples–Moon -~68 samples– Mars - ~34 samples– Comets?– Venus?– Mercury?– Other solar systems?MeteoritesAlmost all are thought to be fragments of asteroidsWhere else can they come from?Peekskill Meteorite•http://aquarid.physics.uwo.ca/~pbrown/Videos/peekskill.htmhttp://aquarid.physics.uwo.ca/~pbrown/Videos/peekskill.htmMeteorites•Meteorites are composed of different minerals– Silicates –contain silicon and oxygen–Sulfides –contain sulfur–Sulfides –contain sulfur– Oxide –contains oxygen– Iron-nickel metalMeteoritesMeteorites are composed of different mineralscontain silicon and oxygencontains oxygenMeteorites•Usually named after the town (or nearest town) where they fell or were locatedMeteoritesUsually named after the town (or nearest town) where they fell or were locatedFalls and Finds• Falls – see them fall• Finds – find themFalls and FindsFall Statistics (greater than 1%)• Meteorite typeFall Percentages• L chondrites• H chondrites• LL chondrites•Irons•Irons• Eucrites• Howardites• CM• Diogenites• AubritesFall Statistics (greater than 1%)Fall Percentages38.0%34.1%7.9%4.2%4.2%2.7%2.1%1.7%1.2%1.0%Where is the best place to find meteorites on Earth?Where is the best place to find meteorites on Earth?Where is the best place to find meteorites on Earth?• Antarctica• Deserts– SaharaWhere is the best place to find meteorites on Earth?Antarctic Meteorites•Designation for which ice field they were found• ALH Allan HillsEET Elephant MoraineEET Elephant MoraineLEW Lewis Cliff•Then year and then number (which gives order of discovery)•For example, ALH 84001 was first meteorite discovered in 1984field season Antarctic MeteoritesDesignation for which ice field Then year and then number (which gives order of discovery)For example, ALH 84001 was first meteorite discovered in 1984-1985How do you know a rock is a meteorite?•Some possible indicators•Presence of Iron-Nickel(FeNi)
View Full Document
Unlocking...