SATURN

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SATURNS MYSTERIOUS MOON TITAN
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Why are Saturn and Titan Important

• Saturn is a miniature Solar System

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Titan is Similar to Young(?) Earth

• Atmosphere
• 1.5xas thick as earths
• Mostly nitrogen, like earth
• 6 methane plus other hydrocarbons

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33 Moons Known around Saturn
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But, Titan earns its name

• Titan is the largest of Saturn's moons, and is
  the second largest moon in the solar system.
  Titan is a complex world more similar to Earth,
  Mars or Venus than it is to outer planets

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Cassini Mission Arrived Last Summer
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Saturn Up Close
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Rings
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Titan Observations- through time

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Recent
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Latest Views from Close Encounter Yesterday
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Titan
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First Shots from Latest Encounter
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Titan Lander (Cassini) January 14
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Much More Exploration at Saturn

• Four more years of study
• 76 orbits of Saturn
• 45 more encounters with Titan

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TOST Summary

• 46 Titan flybys
• Scattered throughout the tour but 2006 and 2007
  are the heaviest
• T0 July 1 2004 (350,000 km) flyby - hours after
  SOI
• TA Oct of 2004 - first RADAR SAR image, Huygens
  Landing site imaging
• TB Dec of 2004 - ORS flyby
• Huygens mission Jan 2005
• Mainly ORS observations during the inbound and
  outbound time wings
• Closest approach varies between RADAR
  observations of the surface, ORS observations of
  the surface, limb, or upper atmosphere, Radio
  Science occultations and bi-static observations,
  or INMS in-situ observations of the atmosphere.
• Pushing the spacecraft
• Over half of the Titan flybys are on thrusters
  (hydrazine usage is an issue)
• Power modes during Radio Science experiments
  usually unique
• Attitude profile during a Titan flyby is
  ambitious
• Always fill both SSRs!
• 4 broad science themes
• Interior Structure
• Surface Characterization
• Atmospheric Properties
• Magnetospheric Interactions

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Atmosphere de Titan
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4 Broad Science Themes

• Interior Structure
• Mass was determined by Voyager. We assume Titan
  has differentiated into core, mantel and crust,
  but what are the dimensions of each?
• Gravity Field experiments by Radio Science
• Does Titan have its own internal magnetic field?
• Surface Characterization
• Surfaces of solid bodies in the solar system are
  altered primarily by three processes impact
  cratering, volcanism, and tectonics. Erosion
  may also play a role on bodies with atmospheres.
• Like other moons in the outer solar system, Titan
  is expected to have a predominantly water ice
  crust. Water at the temperatures in the outer
  solar system is as solid and strong as rock.
• Liquids on Titans surface
• Hydrocarbons in Titan's atmosphere pass some
  amount of time as the aerosol haze obscuring the
  surface, gradually drifting to the surface.
• Theoretically, they should accumulate on the
  surface, and, over the life of the solar system,
  would produce a global ocean of ethane,
  acetylene, propane, etc., with an average depth
  of up to 1 km. THIS IS AN IRREVERSIBLE PROCESS
  and the current quantity of CH4 in Titan's
  atmosphere, if it isn't re-supplied will be used
  up in 10 million years.
• Recent earth-based results suggest that there are
  local regions of liquids
• RADAR and the orbiter imagers will observe the
  surface through wavelength windows

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4 Broad Science Themes

• Atmospheric Properties
• Titans smoggy atmosphere dominant atmospheric
  constituent is nitrogen (N2), Methane (CH4)
  represents (very) roughly 6. Surface pressure
  is 1.5 bars, 50 greater than that of Earth, in
  spite of Titan's smaller size, and the opacity of
  Titan's atmosphere is caused by photochemical
  smog
• What is the source of the nitrogen in Titans
  atmosphere?
• How is methane supplied to Titans atmosphere?
• The orbiters spectrometers will detect chemical
  species, look for absorption features in spectra
  acquired from stellar and solar occultations.
• The orbiter imagers will study circulation by
  tracking clouds. Temperature profiles and
  thermal maps influence Titans weather.
• Composition of ions and neutrals very high
  measured in-situe by INMS
• Magnetospheric Interactions
• Titan orbits Saturn at a distance of 20.25
  Saturn radii.
• This puts Titan in the magnetosphere of Saturn
  most of the time, but occasionally outside in the
  solar wind.
• When Titan is in Saturn's magnetosphere it
  affects the configuration of the magnetosphere
• Saturn's magnetic field lines were observed to
  "drape" around Titan.
• The "plasma" (energetic charged particles)
  flowing into and around Titan produces a wake
  similar to that of a boat speeding through water.

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TA - October 26, 2004

• Closest approach is 1200km (altitude) on
  2004-300T153021 (Spacecraft Event Time, UTC) on
  thrusters
• Inbound illumination is lit, closest appoach to
  Saturn (periapsis) follows 2 days later
• TA Data received on Earth between 630pm and
  330am on October 26th. 3445 Mbits Total
• Science Highlights
• First SAR (Synthetic Aperature RADAR) imaging of
  Titans surface.
• Sample the upper fringes of Titans atmosphere
  with INMS
• First very close orbiter imaging including
  Huygens landing site. Very low phase angle
  (15-36 degrees)
• Inbound and outbound atmospheric investigations
  to support atmospheric modeling of Titans
  atmosphere for Huygens Mission

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SUMMARY

• THE EXPLORATION OF TITAN IS AT THE VERY HEART OF
  THE CASSINI / HUYGENS PLANETARY MISSION.
• TITAN IS THE SOLE FOCUS OF THE HUYGENS PROBE AND
  ONE OF THE MAIN TARGETS OF THE CASSINI ORBITER.
• By combining the results from the Cassini
  mission with Earth-based astronomical
  observations, laboratory experiments and computer
  modeling, scientists hope to answer basic
  questions regarding the origin and evolution of
  Titan's atmosphere, the nature of the surface,
  and the structure of its interior.