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Titan: Saturn's Crown Jewel

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Titan: Saturn's Crown Jewel Titan: Saturn’s Crown Jewel CJ Hansen Earth 390 Source: Cassini Orbiter Titan: Basic Facts -Saturn’s largest moon, second largest satellite in solar system -Discovered by ChrisFaan Huygens, March 25th, 1655 -Diameter of 5150 km, (0.4 Earth Diameters) -Only satellite with a dense atmosphere -InteresFng features include hydrocarbon lakes, subsurface water ocean, and a vortex at the south pole Size Comparison To-Scale Discovery and Naming -Discovered by ChrisFaan Huygens, March 25th, 1655 -aer discovering rings of Saturn, surprised to discover that a moon orbited as well -IniFally named “Saturn’s Moon” by Huygens, later named Titan by John Herschel in 1847 -Saturn was the Roman version of the Greek Cronus, who was a Titan Huygens Herschel Missions to Titan Pioneer 11: Arrived September 1st, 1979 Voyager 1: Arrived November 12th, 1980 Cassini-Huygens: Arrived July 1st, 2004 Pioneer 11 -Took some images of Titan, as well as temperature readings -Temperature found to be very cold Saturn and Titan Titan Voyager 1 -Flyby of Titan considered criFcal to mission -Data allowed for constraints on the mass and size of Titan, as well as atmospheric composion -Thick atmospheric haze conFnued to obscure the surface -Layers of haze can be seen in voyager 1 images Cassini-Huygens Mission composed of two probes: Cassini Orbiter -Equipped with various spectrographs, able to image in microwave infrared, opFcal, and ultraviolet spectra -RADAR instrument specifically designed to unveil the surface features of Titan -Currently orbiFng Saturn on its second extended mission Huygens Lander -Landed on surface of Titan January 14th 2005 (Sent data for ~90 min aer landing) -Instruments allow for composiFonal analysis, imaging, and other measurements -Most distant successful landing of any human made probe Cassini Images Imaging Science Subsystem (ISS) Visual and Infrared Mapping Spectrometer (VIMS) RADAR Huygens Images Images taken during descent and aer landing Atmosphere Approximately 98% Nitrogen, 2% Methane and Hydrogen (Coustenis & Taylor 2008) Atmosphere makes Titan the most earthlike body in the solar system -Methane acts similarly to water, forming clouds, rain, rivers, lakes Tan et al. 2014 finds that liquids on Titan exhibit exoFc behavior: the density increases with temperature but decreases with pressure at temperatures above 89.8 K Tan et al. 2014 Methane Clouds Atreya et al. 2006 finds that sunlight should have converted all of Titan’s methane to more complex molecules, therefore there is likely an interior source of methane on Titan Important to note: Titan’s seasons are determined by Saturn’s orbit. Northern Hemisphere summer began in 2010, atmosphere acFvity may change with season as me progresses. Clouds imaged over a 2 day period by Cassini’s ISS South Polar Vortex Cloud at south pole rotates every 9 hours, much faster than ~15 day rotaon of Titan Cloud formed as southern hemisphere moved into autumn Contains high amounts of hydrogen cyanide (de Kok 2014) Hydrocarbon Lakes Northern lake region: even with change of season, lakes Specular reflecFon confirms retain shape existence of surface lakes, discovered in 2009 Lakes tend to be concentrated around the poles Cordier 2011 uses a computer model to determine the composiFon of the lakes: ~75% ethane, ~10% methane, ~7% propane, ~8% hydrogen cyanide, nitrogen, butane, others Large bodies are called “Mare” while the smaller bodies are called “Lacus” Size comparison: Ligeia Mare vs. Lake Superior Hydrocarbon Lakes Tan et al. 2014 Formaon of Titan -Mandt, 2014 concluded that the planetesimals of Titan had to have formed in the cold Protostellar Nebula, not in the warm Saturnian Nebula -This comes from low abundancies of NH3, which form in higher temperatures associated with Saturn’s formaon -Asphaug & Reufer, 2012 suggest that Titan was formed as the result of numerous collisions -Believe that Saturn had a system similar to the Galilean moons pre-coalescence that became unstable -Could explain Titan’s high orbital eccentricity (0.029) -also a possible explanaon of Trojan moons Large degrees of Fdal warping indicate a subsurface ocean (Mitri, 2014) Future Missions Sadly, nothing is certain, but NASA awarded a grant to a project looking into the possibility of a submarine to explore Kraken Mare Previous proposals such as the Titan Saturn System Mission have been rejected, giving priority to Jupiter/Europa missions References Asphaug & Reufer, Late origin of the Saturn System, Icarus, vol. 223, pp 544-565, 2013 Atreya et al., Titan’s methane cycle, Planetary and Space Science, vol. 54, pp 1177-1187, 2006 Cordier et al., Titan’s lakes chemical composiFon: sources of uncertainFes and variability, European Planetary Science Congress Abstracts, vol. 6, p 595, 2011 Coustenis & Hertzig, Cassini-Huygens results on Titan’s surface, Research in Astronomy and Astrophysics, vol. 9, no. 3, pp 249-268, 2009 Elachi et al., RADAR: The Cassini Titan Radar Mapper, Space Science Reviews, vol. 115, pp 71-110, 2004 Mandt et al., Protosolar Ammonia as the Unique Source of Titan’s Nitrogen, The Astrophysical Journal Leers, vol. 788, pp 24-28, 2014 Mitri et al., Shape, topography, gravity anomalies and Fdal deformaon of Titan, Icarus, vol. 236, pp 169-177, 2014 Tan et al., Titan’s liquids: exoFc behavior and its implicaons on global fluid circulaon, Icarus, vol. 250, pp 64-75, 2015 Cassini-Huygens Images: hlp://saturn.jpl.nasa.gov/photos/?subCategory=10 .
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