Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Exploring the MoonSlide 22Slide 23Lunar AstronautsWhere did they go?Slide 26Slide 27Internal Structure of the MoonSlide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Slide 41Slide 42Slide 43Slide 44Class 6: Celestial Motions &The MoonClass updates:• Reading: : 18.4, 22.1-22.5, 24.1• Homework 3 posted todayToday’s topics:• Exploration • Surface features, craters• Lunar historyClass 6: Celestial Motions &The Moon• Seasons• Lunar phases• EclipsesRotation & RevolutionrevolutionrotationReason for Seasons?EquatorNorth Pole23.5°EquatorEarth’sorbitEarthSunSpin axisEarth’sorbitSunReason for SeasonsSunNHSH(Summer)(Winter)Earth’sorbitEarthSunSpin axisEarth’sorbitSunReason for SeasonsNHSH(Winter)(Summer)SunNorthern Hemisphere SeasonsSeasons, Tropics, & CirclesSeasons ReviewReason for Seasons Movie• Why are days are longer in the summer, shorter in the winter?Day/Night & the SeasonsWinter sunpathSummer sunpathThe Phases of the MoonTimes of Moonrise and MoonsetPhase Moonrise MoonsetNew Dawn SunsetFirst Quarter Noon MidnightFull Sunset DawnThird Quarter Midnight NoonWhy We Always See the Same Side of the MoonDay 1Day 7Day 14Day 21NPEclipseslunar eclipse total solar eclipse partial solar eclipseLunar Eclipses• Moon moves in between Sun and Earth, blocks sunlight• Only from within the tiny area where the dark umbra touches the Earth will you see the Sun completely covered and witness a total eclipse.• From anywhere in the grey penumbra, you will see some part of the sun shining from behind the moon. The penumbra is the area of partial eclipse. Solar EclipsesHow do they happen?The Moon is much smaller than the Sun so how can the Moon block out the Sun?Solar EclipsespartialeclipsetotaleclipseSolar Eclipse MovieMovie of solar eclipse taken in India (NASA Goddard Space Flight Center)Eclipses: Why so Infrequent?Why isn’t there a solar eclipse & lunar eclipse once every month?Earth’sorbitMoon’sorbitSunEarth MoonExploring the Moon1959: Luna 2, 3 (USSR)1964: Ranger 7 (US)1966: Luna 10 (USSR)1969-1972: Apollo 11, 12, 14, 15, 16, 17 (US)1996: Clementine (US)1998: Lunar Prospector (US)Apollo 11Astronaut Eugene Cernan, Apollo 17Orbiting & Landing on the MoonSaturn V RocketCommand Module Landing ModuleGoing HomeLunar AstronautsBuzz AldrinApollo 11Neil Armstrong Apollo 11Michael CollinsApollo 11Charles Conrad Apollo 12Richard GordonApollo 12Alan BeanApollo 12Alan Shepard Apollo 14Stuart RoosaApollo 14Edgar MitchellApollo 14David ScottApollo 15James IrwinApollo 15Alfred WordenApollo 15John YoungApollo 16Thomas MattinglyApollo 16Charles DukeApollo 16Eugene CernanApollo 17Ronald EvansApollo 17Harrison SchmittApollo 17Where did they go?Collecting Lunar SamplesAstronaut Harrison Schmitt, Apollo 17Lunar Samples Back at EarthGenesis rockInternal Structure of the MoonmantlecoreCratered highlandsMaria lowlandsLunar Regolith (surface)Harrison Schmitt, Apollo 17Cratered Highlands vs. Lunar MariaCratered highlandsLunar MariaTopography: Nearside vs. FarsideNearsideFarsidexxLunar topography, kmLunar Craters40 kmLanding Module, Apollo 12HerschelcraterPtolemaeusEl PasoLas CrucesCrater FormationSimple craters Complex cratersLunar Craters: Characteristicsmany crater sizesejecta blanket ejecta raysWhy are Craters Important?Local StratigraphyDavy crater chainYZXPractice: Lunar StratigraphyPlace craters X, Y, Z in order of DECREASING age:Oldest --> YoungestA. X, Y, ZB. Z, Y, XC. Y, Z, XD. Y, X, ZRelative vs. Absolute Ages21Lunar Ages from CratersoldestyoungestCratering Through Lunar HistoryTime out: Earth EvolutionFormation of the MoonFormation of the Moon•Gravitational & orbital stability• Satellites (it is one)• Size (radius) 1737 km• Bulk density 3.3 g/cm3 • Surface gravity 1/6 of Earth’s• Volcanism mostly prior to 3.3 Gyr ago• Moonquakes yes, mostly tidally triggered • Rotation 29.5 days• Orbit 27.3 days• Atmosphere none• Surface pressure 0• Surface temperature -170 - 130° C• Plate tectonics no• Water yes/no The