Bulk Characteristics of Titan
• Diameter: 5,150 km
• Average Density: 1.88
g/cm3
• Surface Temperature: 97K
• Surface Pressure: 1.5 bars
• Theorized to have an
interior liquid layer
composed of ammonia and
water ice
Guide to Titan
• Titan parallels early Earth
▫ Lakes, Atmosphere, Clouds,
Rain, Volcanoes, Plate
Tectonics.
• Only other body in solar
system known to harbor stable
liquids on its surface.
▫ Weather cycle
▫ Good indications for life or at
the very least, pre-earth
conditions.
Atmosphere
• Only known moon with an
atmosphere.
• 1.45 Denser than Earth’s
▫ 1.19 times as massive.
• Result of volcanism or
microbial life.
• Like a young planet Earth.
▫ Research simulated atmospheric
conditions and were given the
building blocks of life.
Rain on Titan
• Recorded evidence of
methane rainstorms on Titan
in 2010.
• Occurred over equator, rather
than at poles.
• Replenishes methane lakes
and river systems.
• Skepticism on whether this is
any indication of life.
Methane Lakes
• Thanks to Triple Point and
rain, Methane Lakes exist on
Titan’s surface
• Only known terrestrial body
other than Earth to have
stable liquids on its surface.
• Not difficult to land.
Cryovolcano
• Winter, S Hemisphere.
• Sotra Facula is a cryovolcano
▫ Emits water with ammonium,
or polyethylene, paraffin
waxes, or asphalt. Possibly
replenishes methane in
atmosphere.
• Located at 12degrees S / 39.8
degrees W
• 235 km wide
Habitability of Titan
• Titan’s PHI is 0.64
• Solid Surface
▫ Evidence of tectonics
• Atmosphere
▫ Nitrogen and Hydrocarbons
▫ Believed to be similar to Earth’s atmosphere before
oxygen was introduced
• Surface Liquid
▫ Titan’s 93K surface temperature is directly above the
triple point for methane (90.68K)
Triple Point
Image Source: http://www.nmij.jp/english/library/units/temperature/triple-chart_en.gif
• The temperature and pressure at
which the three phases (gas,
liquid, and solid) of that
substance coexist in equilibrium.
• Different changes in temp and
pressure transform substance to
ice, liquid, vapor.
• EARTH’S SURFACE: temps and
pressures similar to the triple pt
of WATER.
• TITAN’S SURFACE: temps and
pressures similar to the triple pt
of METHANE.
Possibility for Methanogenic Life
• 2005 – Chris McKay suggested
that methane-based (rather than
water-based) life on Titan could
consume hydrogen, acetylene,
and ethane – i.e. organisms called
methanogens.
• EARTH = O2 metabolism
Image Source: http://www.engr.ku.edu/images/media/methanotrophs.jpg
C6H12O6 (glucose) + O2 -> CO2 + H2O
Methanogenic Life (continued)
Titan’s organisms would:
•Inhale H2 
instead of O2
•React it with acetylene (or CO2) 
instead of glucose
•Exhale methane 
instead of carbon dioxide
•TITAN= H2 metabolism
Water is widespread on Earth, therefore life is
widespread on Earth because it uses water.
Analogous to Earth = Liquid methane lakes are
widespread on the surface of Titan.
C2H2 (acetylene) + 3H2 -> 2CH4
Photo source: http://upload.wikimedia.org/wikipedia/commons/thumb/e/e8/PIA10008_Seas_and_Lakes_on_Titan.jpg/300px-PIA10008_Seas_and_Lakes_on_Titan.jpg
The Miller-Urey Experiment
• The Experiment (1953):
▫
▫
▫
▫
INORGANIC components  ORGANIC components in conditions similar to pre-biotic Earth.
Warm water + four gases [H2O, CH4, NH3, and H2] + electrical discharges
Formed simple organic molecules, including amino acids and RNA nucleotides.
Formed the idea that on pre-biotic Earth there existed an abundance of RNA life produced through
chemical reactions.
• In the search for extraterrestrial life? Helps to understand the conditions required for life to
form.
• Titan’s atmosphere lacks oxygen, but complex organic molecules are present.
▫  Could form biological materials in a pre-biotic habitat resembling that of early Earth.
Photo source: http://www.chem.duke.edu/~jds/cruise_chem/Exobiology/Pmilurey.gif
Titan as a Prebiotic Environment?
• Possible host for microbial
extraterrestrial life because of its
pre-biotic-like environment rich
in complex organic chemistry.
• Possibly subsurface liquid ocean
serving as a biotic environment.
• Implications of a possible
ammonia-water ocean inside
Titan.
Yellow = hazy surface of Titan
Light gray = ice layer starting near the
surface
Blue = internal ocean
Light gray = another layer of ice
Dark gray = mixture of rock and ice in the
interior
Past Mission: Cassini-Huygens
• NASA / ESA / ASI Spacecraft
to study Saturn and its
satellites.
• Launched in 1997, reached
system in 2004
• Cassini: first to enter Saturn’s
orbit.
▫ To study structure and history
of the rings and satellite
surfaces.
▫ Studies Titan’s cloud, hazes,
and regional surfaces.
Huygens Probe
• Reached Titan Jan 14th, 2005
• Sent data for 90 minutes after touchdown.
• Designed to brake in atmosphere and parachute a robotic lab
to the surface.
• Sent signals to Cassini to relay back to Earth.
Huygens Design
• Heat shield and parachute.
• 6 Types of Instrumentation to study:
▫ Physical and electrical props of
atmosphere
▫ Radiation balance in Titan’s
atmosphere
▫ Chemicals in Titan’s atmosphere
▫ Volatiles and decompose complex
organic materials
▫ Physical properties at point of
impact.
Huygens Findings
• Landed in “Titanian
Mud”
• Rounded pebbles imply
possible fluid motion.
• Dense cloud or thick
haze ~ 18 – 20 km from
surface.
Two New Proposals: TSSM and TiME
• Titan Saturn System Mission
▫ Consists of an orbiter and 2
probes.
▫ More features than Huygens.
• Titan Mare Explorer
▫ Land in and travel around a
methane lake.
▫ To sample and analyze organics
for 3 – 6 months.
▫ New power source: Advanced
Stirling Radioisotope
Generator.
Goals of TSSM & TiME
• Explore Titan as a system.
• Study Titan’s organic inventory
and astrobiological potential
• Constrain Titan’s origin and
evolution models.
• Recover information on
Enceladus and Saturn’s
magnetosphere.
Mission: PLOT
Landing on Titan
•
•
•
•
Probe for Life and Organics on Titan
Land in Lake Ontario Lacus
Possibly explore nearby cryovolcano
Look for Evidence of Life: CO2, acetylene, amino acids,
enzymes, isotopic fingerprints
▫ Use Cassini to relay back data
Advanced Stirling Radioisotope
Generator
Landing on Titan
▫ Powerful generator currently being developed by NASA.
▫
▫
▫
▫
≥14 year lifetime
Mass ~ 20 kg
Uses 0.8 kg plutonium-238
January 2015
Source: NASA
Testing
Testing
• Mass Spectrometer
• Composite Infrared Spectrometer
▫ Test for hotspots in lake
• MOD III
• Seismometer
• Camera
Image Source: NASA
Mission Target- Ontario Lacus
• Located at 72° S & 183°W
• Composed of methane,
ethane, and propane.
• Volume: 7-50 km3
Ontario Lacus
Tour of Ontario Lacus
http://www.youtube.com/watch?v=kK4n5
l7bHSw
Timeline
Timeline
2017: Launch
2024: Land
The goal is to land and test during
winter in the Southern Hemisphere.
2017
2024
Cost
Mission
Cost ofof
Mission
• Proposed Cost:
1 billion
▫ Includes cost of designing and launching a new probe.
▫ Use of the orbiter from the Cassini mission will cut costs
• Cassini-Huygens mission (launched 1997) cost NASA
3.2 billion!
The Search for Life
Bibliography
… is expensive but IMPORTANT!