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Published byBarnard Edwards Modified over 9 years ago
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Our Moon! (Been there… …done that…)
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Crew of Apollo 11: First Astronauts to Walk on the Moon!
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(Really… we have been there!)
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A Highly Trained, Professional Lunatic (P.S.: Our Moon = “Luna”)
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“The Moon”: A great place for golfing? No, too many divots… (Alan Shepard, Apollo 14)
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How Craters are Made (…obviously…)
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Some nice craters …Named after scientists, mountains, “seas of storms” (Mare Imbrium)…
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A “Man in the Moon”? (…No, I’ve never really seen it, looking up in the sky…)
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Even the ejected pieces (“tektites”) from old craters, have their own new “craters”! Many Lunar Craters = scars from “Heavy Bombardment” period in the early Solar System…! Older surfaces More Heavily Cratered!
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http://vimeo.com/15610496 But where does the Moon come from? (Numerical Simulation) (Video) Our Moon was formed by a collision! (…we think…) Within the first ~50 Million Years (or so) of the Solar System’s history, a ~Mars-sized object hit the Earth…
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How do we know that our Moon was formed by a collision? …just like good (bad?) pizza, our Moon is mostly crust! Similar to Earth’s crust, that is. (Plus hints from its isotopic composition, fast angular momentum…)
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The Cycle of Lunar Phases (Depending upon the positions of the Sun, Moon, Earth, and the Observer…) Moon-Rise/Set times for different phases:
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Sidereal Month (“by the Stars”) vs. Synodic Month (“by the Phases”) What exactly is a “Month”, anyway?
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What is a “Blue Moon”? The term blue moon originates in folklore. One “lunation” (an average lunar cycle) is 29.53 days. Therefore, 12.37 lunations occur in a solar year. Different traditions place the “extra" blue full moon at diff. times: The Maine Farmers' Almanac – An extra full moon in a season. One season was normally three full moons. If a season had four full moons, then the third full moon was called a blue moon. In calculating the dates for Lent and Easter, the Christian clergy identified a Lenten moon. Historically, when the moons arrived too early, they called the early moon a betrayer (belewe) moon, so the Lenten moon came at its expected time. Folklore named each full moon according to its time of year. A moon that came too early was called a blue moon; the rest of the moons that year retained their customary seasonal names. The second full moon in one calendar month is sometimes called a blue moon. This usage results from a misinterpretation, in the March 1946 issue of Sky and Telescope, of the traditional definition of blue moon. Blue moon of Dec. 31, 2009, with partial lunar eclipse
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Eclipses! “Lunar” & “Solar”
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The Corona (“crown”) of the Sun Viewable only during a Total Solar Eclipse:
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Why No Eclipse every month?
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Only get Eclipses when Luna is in the “Ecliptic Plane”! (… well, Duh!...)
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“Tidal Forces”: Any Uneven, Stretching Gravitational Pull! (Ex: Luna creating Earth’s Ocean “Tides”!)
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Do the Sun & Moon work together to make stronger tides? (…sometimes yes, sometimes no…) “Syzygy”!
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Tidal “Friction” #1: “Tidal Locking” of Luna into Synchronous Rotation about Earth!
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Two very different sides of our neighbor, Luna: Near Side (always seen) Far Side (never seen!)
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Great Music… …Bad Astrophysics!
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Tidal “Friction” #2: “Tidal Braking” slows Earth’s daily rotation about its axis! Conservation of Angular Momentum… Earth experiences Longer Days! Causes Lunar orbit to spiral out, farther & farther away from Earth! (No more Total Solar Eclipses!) (…from the solid Earth bulging ~tens of cm each high tide…)
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