Moons of Saturn Titan: bright enough to be seen in a Wal-Mart telescope



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tarix05.03.2018
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Moons of Saturn




Titan: bright enough to be seen in a Wal-Mart telescope

  • 1944: discovery that spectrum had absorption lines of methane: a moon with an atmosphere. Known to be about twice the mass and about 50 percent larger in diameter



First real look at Titan in 1979 with Voyager flyby



Inferences about the surface of Titan



25 years later…another spacecraft on a mission



The Cassini and Huygens spacecraft



Concept of the Huygens lander…an artist’s conception



Pictures of Titan from the approaching Cassini spacecraft



A new view of Titan (from close up)



The view from Huygens on the way down



Closer to the surface



Titan has flow channels, too



On the surface



Cassini radar shows lakes of methane



Recent observations from Cassini show different manifestation of methane lakes: sunlight glints from the lake surfaces



Reasons for the interest and importance of Titan: it has a dense atmosphere and a “hydrological cycle” based on another compound. Despite its alien nature, in some ways it is the most Earth-like object in the solar system



The surface of Titan: an artist’s view



Another moon of Saturn: Enceladus

  • Diameter=500km

  • Mass = 0.0012 that of Earth’s Moon

  • Orbital period=1.37 days

  • Semimajor axis of orbit=238,000 km

  • Semimajor axis of orbit = 4.0 X radius of Saturn



Cassini gives a closeup view of Enceladus



Why Enceladus is of interest



Enceladus: another case in which subsurface water flows up through cracks to the surface of the object



Summary: several moons of the outer planets, in addition to being amazing natural spectacles, may be abodes for primitive forms of life, or at least give us some insight into the astro-biochemical processes which gave rise (or didn’t) to life. Future spacecraft will have much to explore. Stay tuned.



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