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Download How Did Our Moon Form and What`s Been Happening Since?
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Earth’s Moon How did our Moon form? and What’s been happening since? What do you see? Evidence a model must explain Moon is less dense than the rocky planets (Mercury, Venus, Earth, Mars) … it’s “lighter”. Less iron than Earth Moon is unusually big for a satellite Earth/Moon system has a lot of angular momentum (spin + orbital motion) Chemical composition similar to Earth’s mantle A tilted orbit relative to Earth’s path around the Sun How Did the Moon Form? Movie Time! Movie of lunar evolution + tour from LRO Find the video here: http://svs.gsfc.nasa.gov/vis/a010000/a010900/a0 10930/evol_and_tour_ipod_lg.m4v Hypothesis accepted by most planetary scientists since mid-1980s: Wham Moon! The GIANT Impact Hypothesis Explore Activity! Lunar Geologic History 4.5 billion years ago, our Moon forms (lunar rocks and meteorites) The Magma Ocean Explore Activities! Moon Mix!, Recipe for a Moon Magma Ocean / Lunar Highland Rocks Anorthosite (a type of feldspar) – mostly CaAl2Si2O8 4.44-4.51 Billion Years Old Explore Activity! Splat! Late Heavy Bombardment “Nice Model” 4.5 billion years ago 3.9 billion years ago 3.85 billion years ago Intense period of impacts on Moon (and everything else in Solar System) by comets and asteroids Lunar Impact Basins (really big craters) Rim of Imbrium Basin Orientale Basin Big, frequent impacts until 3.8 billion years ago Impact events continue across our solar system today! Lunar Impact Rocks Breccia Lunar Geologic History Filling in the Basins Mare Imbrium SW Mare Imbrium Volcanism after impacts – most before 3 (to 1) billion years ago Explore Activity! Moon Ooze Lunar Basin Rocks Basalt 3.3 Billion Years Old Volcanoes on the Moon There are a few actual volcanoes on the Moon Not nearly as many as Earth! No longer active Lunar Geologic History - Basins Dark, smooth Maria Basalt – fine grained dark igneous rock rich in iron and magnesium (heavy stuff that sank in magma ocean) Few hundred meters thick Rocks are 4.3 to 3.1 billion years old … flows as recently as 1 billion years ago A Brief Summary of Lunar Geologic History Moon Mix! Splat! Moon Ooze Impact Paintings and … Tidal Evolution The Moon is far from the Earth! Why? The Moon is moving away from Earth by 3.8 centimeters each year! On average, the Moon is about 7 feet further away than when I was born Moon was close to Earth billions of years ago. All quiet except for impacts... Like this one in 2005 that made a 9 foot crater … 0.15 seconds Explore Activity! Lunar Geologic History – Recent Activity Trails of the Apollo 12 Astronauts Explore Activity!
