Various and Sundry aboutTerrestrial PlanetsFun Questions1) What’s the most biologically important species on theplanet? That is, if we were to add up the mass of all themembers of every species, which species would have themost mass?a) peopleb) whalesc) termitesd) mosquitoes2) Burning 20 gallons of gasoline in your car producesa) 4 pounds of CO2b) 40 pounds of CO2c) 400 pounds of CO2d) 4,000,000 pounds of CO2Fun Questions1) Marsa) has no water on its surfaceb) has ice but no liquid waterc) liquid water but no iced) polar caps made mostly of water ice2) Many scientists believe that Mars once had flowing waterbecausea) geological forms such as river deltas, streambeds etc.appear to have been formed by erosion due to flowingwater.b) of the presence of minerals that usually form in thepresence of liquid water.c) the Mars climate orbiter has photographed lakesd) a and bFun Questions1) What’s the most biologically important species on theplanet? That is, if we were to add up the mass of all themembers of every species, which species would have themost mass?a) peopleb) whalesc) termites(about 10x as much as people)d) mosquitoes2) Burning 20 gallons of gasoline in your car producesa) 4 pounds of CO2b) 40 pounds of CO2c) 400 pounds of CO2d) 4,000,000 pounds of CO2Fun Questions1) Marsa) has no water on its surfaceb) has ice but no liquid waterc) liquid water but no iced) polar caps made mostly of water ice2) Many scientists believe that Mars once had flowing waterbecausea) geological forms such as river deltas, streambeds etc.appear to have been formed by erosion due to flowingwater.b) of the presence of minerals that usually form in thepresence of liquid water.c) the Mars climate orbiter has photographed lakesd) a and bShow Rover MovieSpirit and Opportunity Landing SitesThe RoverPancam views the surface around the rover, using twohigh-resolution stereo cameras to complement therover's navigation cameras.In order to look at the interior of rocks, a field geologist on Earth uses a rockhammer. On the Athena payload, the job of a rock hammer is done by theRAT -- the Rock Abrasion Tool. The RAT is positioned against a rock by therover's instrument arm, and uses a grinding wheel to remove dust andweathered rock, exposing fresh rock underneath. The RAT exposes an areanearly 5 cm (2 inches) in diameter, and grinds down to a depth of about 5mm (0.2 inches).The view from inside opportunity’s craterView of the lander and parachute taken with Pancam on theRover.Virtues of High Resolution: Mars BlueberriesSmall round pebbles in theEscalante NationalMonument, Utah. We knowthat these are produced inwater.Small round pebbles on Marsphotographed by opportunity,nicknamed “blueberries.”Spectroscopy Reveals that theBlueberries are rich in MematiteHematite, Quartz Fe 2O 3Florence Mine, Egremont, West Cumbria, Cumbria,England, UKSpecimen 5cm wide. Specimen & photo by CrystalClassics.Islands in the StreamThe teardrop shape is characteristic of water flowing past an obstacle.Ancient Sediments?So, we think that there was once liquidwate on Mars. What do we do now?Let’s talk about Volcanoes some more.View of Hawaiian Islands from SpaceOlympus Mons and Mauna KeaAs the image shows, Olympus Mons is muchlarger than even the Hawaian volcanoes. This is alittle surprising considering that Mars is muchsmaller than Earth. Is there a reason for this?ContinentalDrift/PlateTectonicsAlfred WegnerBorn in 1930 in Germany,Wegner obtained a Ph.D. inAstronomy from theUniversity of Berlin at the ageof 24. He became interestedin the climate of polar regionsand participated in expeditionsto Greenland. He was injured in WWI and spent the remainder ofthe war and some years afterwards as a meteorologist. His mostfamous contribution though was the theory of Plate Tectonics,conceived in 1911. Wegner died in Greenland in 1930.My least favorite Miles DavisAlbum, from his unfortunate“fusion” phase. Listen toKind of Blue instead.Ever seen one of these?Formation of Hawaiin IslandsVenusHistory of ExplorationMariner 2 1962Venera 3 1965Venera 4 1967Mariner 5 1967Venera 5 1969Venera 6 1969Venera 7 1970Venera 8 1972Mariner 10 1973Venera 9 1975Venera 10 1975Pioneer Venus I 1978Pioneer Venus II 1978Venera 11 1978Venera 12 1978Venera 13 1978Venera 14 1978Venera 15 1978Venera 16 1978Vega 1 1986Vega 2 1986Magellan 1991Venus Express 2006White-flyby, Yellow-Orbiter, Blue-Probe, Pink-BallonMagellanRadar wavelength = 12 cmCloud particle size ~ 1 µmRadar can “see” throughclouds!Key Results from Magellan• The surface of Venus is mostly covered by volcanicmaterials. Volcanic surface features, such as vast lavaplains, fields of small lava domes, and large shieldvolcanoes are common.• There are few impact craters on Venus, suggesting thatthe surface is, in general, geologically young - less than800 million years old.• The presence of lava channels over 6,000 kilometers longsuggests river-like flows of extremely low-viscosity lavathat probably erupted at a high rate.• Large pancake-shaped volcanic domes suggest thepresence of a type of lava produced by extensiveevolution of crustal rocks.• The typical signs of terrestrial plate tectonics - continentaldrift and basin floor spreading - are not in evidence onVenus.Why is Plate Tectonics Important?Carbon Cycle on EarthOn Earth, CO2 dissolvesin the oceans and iseventually incorporatedin carbonate sedimentson the sea floor.Subduction at plateboundaries carries thesesediments far below thesurface where they aredecomposed at hightemperature reformingCO2. The CO2 isreleased back to theatmosphere throughvolcanoes.Fig. from The New SolarSystem.Carbonates(CaCO3)CO2Why are Venus, Earth, and Mars so Different?Plate Tectonics. Probably the largest differencebetween the Earth and Mars andVenus is that our interior is moreactive. The Earth is the only planetwith plate tectonics. This constantlyresupplies the surface with newmaterial such as H2O and CO2.Lacking this resupply mechanism,carbon and oxygen on Mars may bebound chemically in inert molecules.As a result the Martian atmosphereand polar caps are tiny incomparison with Earth.A volcanic eruption on Earth. Thoughthe molten rock and noxious fumesget all the attention, the primaryproduct of a volcanic eruption iswater.Atmospheric TemperaturesFig. from The New Solar SystemHypothetical HistoryOriginally Mars, Earth, and Venus had large amounts of CO2and H2O.On Earth, there is a constant flux of CO2 into and out of themantle. Most
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