Titan's moon

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Saturns Moon Titan shows many incredible features as; only liquid bodies observed in the solar other than Earth, huge seas of hydrocarbons, only moon with a thick atmosphere and also are similar to Earth in that it is dominated by nitrogen, methane and argon. Surface features consistent with erosion and however, it seems highly doubtful it is a good candidate for life.


<ul><li> 1. Saturns Moon TitanASL NASA AMESRenee Condori Apaza, Bishun N. Khare,Christopher P. McKayThe Advanced Studies Laboratories</li></ul> <p> 2. The Giant Moon Titan was the sixth moon ever to bediscovered, in 1655 by Dutch astronomerChristian Huygens. Named due to its massive size, Titan wasoriginally thought to be the solar systemslargest moon.That title goes to Ganymede(Jupiter) Through a large telescope, Titan appearsas a pale orange ball. Even Voyager 1 sawlittle detail. 3. Value of space missions Voyager 1 Cassini-Huygens (NASA-ESA) Extremely little known about Utilized the information learnt Titan prior to Voyager 1from Voyager to include Provided enormous amount Imaging spectrometer to see of information about Titans through the haze (VIMS) atmospheric composition GCMS on Huygens to look Also provided estimates ofat atmosphere composition atmospheric structure andduring descent temperature SSP surfacesciencepackageshttp://saturn.jpl.nasa.gov/home/index.cfm 4. Useful facts about Titan Titans diameter of 5150 km is larger than Mercury but smallerthan Mars Titan rotates very slowly one Titan Day corresponds to about16 Earth days Titan is tidally locked around Saturn just like our own Moon Same face always points toward Saturn Orbital period must also be 16 Earth days With Saturns orbital period being 29.5 Earth years, a year onTitan contains about 673 Titan Days Inclined at 26.7 to the Sun (cf Earths ~23) =&gt; Titanexperiences seasons Without being able to take soundings we know very little aboutits internal structure 5. Titans surface is obscured byclouds Titans size was originally over-estimated: we are looking at dense,thick layers of opaque haze, not thesurface. Voyager 1 snapshots of the planetsedge (1980) showed that the haze wasmulti-layered. Voyager 1 was crucial in determining the size of Titan - used radiowaves to penetrate the haze 6. Tholin and Titan haze The atmosphere shows very distinct haze layers. The origin of these layers is not yet understood (possibly related to a wave- type phenomenon in the atmosphere). 7. Atmospheric CompositionWe now know that the atmosphere is largely composed ofnitrogen. Sound familiar? In addition, the atmosphere contains several percent of methane,and many compounds of H, C, Ar : but no free O2. 8. Composition of Titans atmosphere(Ralph Lorenz and Jacqueline Mitton. 2002)MoleculeRelative abundance on Titan(Earth) N297% (78%)CH43% (0.000175%) H2 0.2% (0.000055%)CO2Aprox. 10 ppm (0.0384%)C2H60.002% (0.000175%)C2H4 10 ppm(0.0004%) 9. Earth vs Titan Atmospheres 10. Temperature of Titan Naively applying the radiation balance model to Titan we findthe estimate for its temperature is: 278 278 Tp = K= K 90 Kd p in AU 9. 5 This is actually very close to the found answer Haze created in Titans atmosphere serves to increase albedo compensating for any greenhouse effect that might occur. Sometimes called an anti-greenhouse effect but is equivalent to the scenario involved in a nuclear winter 11. Temperature in the atmosphere 12. Phase diagram for methaneOne bar is about1 atm.Pressure at surfaceof Titan isabout 1.5 barExpect to find both Titans average surface templiquid and gaseousforms of methane 13. Atmospheric chemistryTitans atmosphere is a giant chemistry lab: UV light from thedistant Sun splits up some of the native methane and nitrogenmolecules, e.g. CH + photon CH + H + H 42 CH4 + photon CH + H + H2 The highly reactive radicals will then bond together in new ways,forming heavier chemicals which are expected to condense and rainout. Comparatively straightforward to form very long chainhydrocarbons through reactions with CH radicals (see G&amp;S180). Over billions of years, huge lakes of liquid hydrocarbons shouldhave accumulated on the surface 14. Tholins Chemistry Reactions 15. Titans Climate At 94 K water willnot evaporate sothere is virtuallyessentially no watervaporin theatmosphere Clouds are composedof methane/ethaneand other simpleorganic molecules Precipitation of theclouds should alsoresult inliquidmethane &amp; ethanerain! Will help formthe proposedlakes and seas ofPolar cloud formationhydrocarbons 16. Lakes of hydrocarbons. an artists impression 17. This view of Titan taken on Feb. 25, 2007, reveals a giant lake-like feature in TitansNorth Polar Region. It is approximately 1,100 kilometers (680 miles) long and has asurface area slightly smaller than that of Earths largest lake, the Caspian Sea. 18. Water on TitanTitan is much too cold for surface liquid water, with atemperature of 94 K (-178C) However, it has been proposed that water could existtemporarily in melt pools produced by impacts.There may also be liquid water under the ice-likesurface Large melt pools hundreds of meters deep might takecenturies or even millenia (if mixed with ammonia) tofreeze completely. 19. Liquid assetsIf liquid water could survive for hundreds of years,that is long enough for interesting chemistry Chemical reactions in surface melts could add oxygenfrom water to the N, C, H in the tholin to makecarboxylic acids, purines and pyramidines (forms basefound in nucleic acids) As mentioned, Titan may well have a sub-surfaceocean like Europe This is needed in many models to allow methane toescape from the interior, and replace the methane lostin the atmosphere by chemistry. 20. Titan Cryovolcano ? Huygens team produced this picture of a possible volcano, withtwo outflowing arms.Rather than spewing lava it is believed to spew a slurry ofmethane, ammonia and water ice 21. Titan Geography Huygens gave us some incredible pictures of smallerscale features. Hills Drainage features Mud flats? Note the camera stopped working before touchdownso there are no detailed images from right above thelanding site 22. The descent NASA movie 23. Panorama of Huygens Images Drainage features Pictures taken while probe will still several km above surface 24. Full 360o view 25. Ziels1 kmThe dark plain is pebbly, and cut by channels.It is also wet with methane and ethane. View from the landing site 26. Oceanography on Titan? Finding another body with liquid content presents theopportunity to hypothesize about the behaviour of those liquids Scientists have modelled the expected wind-driven wave heightsfor hydrocarbon seas.VariablesTitan EarthSignificant wave height / m 4.5 0.6Wave speed / m s-15.5 5.5Wavelength / m 10511Period /s11.5 3.5 Anyone for surfing on Titan? 27. Life on Titan? As we might expect, the possibility seems very remote If there is life it would probably be imbedded in a waterlayer embedded under ice Little oxygen though, and the low temperatures make this possibility even less probable Possibly earlier in its life Titan was sufficiently warm(following its formation) Alternatively, when the Sun becomes a supergiant Titanstemperature is expected to rise to (a balmy!) 170 K Still a long way from freezing point of water though 28. Summary Titan shows many incredible features Only liquid bodies observed in the solar other than Earth Huge seas of hydrocarbons Only moon with a thick atmosphere Similar to Earth in that it is dominated by nitrogen Surface features consistent with erosion However, it seems highly doubtful it is a good candidate forlife 29. THANKS SO MUCH</p>


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