Earth and Moon Seen from MarsCourse AnnouncementsCourse AnnouncementsAssignmentsThe Overview EffectEdge of Mt. SharpFoot of Mt. SharpJagged LandscapeWafer Thin RocksMartian SunsetCuriosity SelfieVictoria CraterMER Opportunity Tire TracksMartian SunsetOrbital PropertiesMars Physical PropertiesGlobal ViewsMartian Surface from orbitMartian TopographyMartian TopographyMartian TopographyLargest Valley in Solar SystemLargest Valley in Solar SystemVolcanism on MarsVolcanism on MarsTharsis Bulge… a ancient plate?Volcanism on MarsWater Features on MarsRunoff ChannelsRunoff ChannelsOutflow ChannelsOutflow ChannelsOutflow ChannelsPeriods of Flowing WaterSubsurface IceSubsurface IceCurrent Flowing WaterCurrent Flowing WaterWhere did the water go?Earth and Moon Seen from MarsCredit : NASA/JPL/Curiosity TeamCourse Announcements•Thanksgiving Week planningNo classes Wednesday, 23 Nov.•Extra Credit sessions still underway•Quiz 5 Today•Quiz 6 next Wednesday, 16 Nov.•Exam 3 is Monday, 21 Nov.•Final Exam: Thursday, 8 Dec. 2:45 – 4:45 PMCourse AnnouncementsAn Astronomy Club!Astronomy Club Interest MeetingA group of enthusiastic students are starting a UT Astronomy Club. They are holding an interest meeting for any people that want to be a part of it.When: Friday, 18 November from 12:30 – 1:30 PMWhere: Nielsen Physics and Astronomy Room 307•Focus of the meeting is to determine level of interest, potential student activities (star parties; learning astrophotography; outreach opportunities; etc.)AssignmentsReading Assignments•Chapter 10: Sections 10.5 – 10.7[Read by Friday, 11 Nov.]•Parallel LecturesCC Astronomy Episode 15: Mars[Watch before Friday, 11 Nov.]Mastering Astronomy•Chapter 9 Homework (short assignment)[Due Thursday 10, Nov. at 11:59 EST]The Overview EffectA reminder of unity and moving humanity forwardIn case you are thinking this today… I want to remind you all of the “Overview Effect”. Astronauts that have looked down upon the Earth from outerspace overwhelming report experiencing a cognitive shift toward a new understanding of the Earth as a small and precious place where unity amongst humans is the paramount feeling.•A reminder to move forward with unity•And now to imagine Dr. Farnsworth’s dreams.Edge of Mt. SharpCredit: NASA/JPL CaltechFoot of Mt. SharpCredit: NASA/JPL CaltechJagged LandscapeCredit: NASA/JPL CaltechWafer Thin RocksCredit: NASA/JPL CaltechMartian SunsetCredit: NASA/JPL CaltechCuriosity SelfieCredit: NASA/JPL CaltechVictoria CraterCredit: NASA/JPL CaltechMER Opportunity Tire TracksCredit: NASA/JPL CaltechMartian SunsetCredit: NASA/JPL CaltechOrbital Properties•Opposition is point of closest approach. Sun – Earth – Planet all in a line•Oppositions occur at roughly 780 day intervals (Synodic Period – opposition-to-opposition or conjunction-to-conjunction period) [ 1/Psyn = 1 – 1/PMars ]•Oppositions near Mars perihelion less frequent occurring once every 15 years or so–Earth-Mars passages within 0.38 AU (Earth at aphelion; Mars at perihelion) even more rare at about 3 times per centuryMars Physical Properties•Rotation period easily obtained by tracking surface features.–One 360o rotation (sidereal day) every24.62 hours (24 hours 37 min)–Martian Days are called sols–Confirmed using radar•Axial tilt also very similar to Earth’s, and is currently at 25o–Mars’ axial tilt, or obliquity, changes between perhaps lower than 10o and as high as 50-60o in a non-period (chaotic) fashion over timescales of hundreds of thousands to millions of years–Combine axial tilt and eccentric orbit (0.29 AU difference between perihelion and aphelion), and Mars has extreme, and complicated, seasonsAnd how we determine them (and what they mean)Global Views•Reddish color (due to iron oxides, i.e., rusts) with dark and light patches that show seasonal variability•Polar ice caps that show seasonal variabilityCharacteristic red color from high abundance of oxidized iron (rust) in the rocks and regolith on the surfaceFrom EarthHubble Space TelescopeViking Spacecraft 1976)Martian Surface from orbit•Mosaic of images taken with Viking spacecraftMajor Large-scale surface features•Tharsis Bulge with four HUGE volcanoes–Largest: Olympus Mons•Huge “canyon” called Valles MarinerisViking global view of MarsLargest mountain (Olympus Mons) and canyon (Valles Marineris) in Solar SystemMartian Topography•Lowland Northern hemisphere is several kilometers lower (~5km) than the southern hemisphere–Characterized by smooth, rolling volcanic plains (not unlike the lunar maria)–Strewn with blocks of volcanic rock and ejecta boulders from impacts•Highland Southern hemisphere is several kilometers higher (~5km) than the northern hemisphere–Cratered highlands with dark mountainous regionsNorth-south hemisphere dichotomyMartian Topography•Northern hemisphere (lower altitude) much less cratered, and therefore, younger (3 Gya) than the more heavily cratered, and older southern highlands (4 Gya)•MGS mapped surface with accuracy of a few metersMars Global Surveyor (MGS)Martian Topography•Tharsis Bulge is roughly the size of North America, lies on the equator, and rises about 10 km above the rest of the Martian surface–Diametrically opposite (antipodal) the Tharsis Bulge, in the southern hemisphere, is the Hellas Basin: a very large impact basin estimated have an age of ~4 Gya (Late Heavy Bombardment times)•Likely caused a major restructuring of the Martian Crust and possibly the creation of the Tharsis BulgeThe Tharsis BulgeTharsis Bulge region in a MOLA (on Mars Global Surveyor, MGS) elevation mapValles Marineris, the biggest canyon in the SS, is to the right (east) of Tharsis Bulge Credit: NASA/JPL-Caltech/ASULargest Valley in Solar System•About 4000 km long (East to West coast of US); up to 120 km wide; and as deep as 7 km•Largest canyon in Solar SystemValles Marineris (Mariner Valley)Largest Valley in Solar System•Associated with the Tharsis Bulge–Theorized to have formed from the same crustal deformation processes. As Tharsis bulged, Valles Marineris split and cracked open•These type of features are called tectonic fractures•Not formed by water!Valles Marineris (Mariner Valley)NASA-JPLVolcanism on Mars•While many shield volcanoes cover the surface, the most prominent are found on the Tharsis Bulge•Largest volcano (in the Solar System) is Olympus Mons–700 km across with surface area about the
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