Mission to Titan

Natalia Alvarez • Kelsey Bertamus • Michael Morgan • Talia Strait • Natalie Taylor

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• 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.

Image Source: http://www.nmij.jp/english/library/units/temperature/triple-chart_en.gif

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 metabolismImage 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 dioxideWater 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

•TITAN= H2 metabolism

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

Yellow = hazy surface of TitanLight gray = ice layer starting near the surfaceBlue = internal oceanLight gray = another layer of iceDark gray = mixture of rock and ice in the interior

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.

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.

Landing on TitanMission: PLOT

• 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

Landing on TitanAdvanced Stirling Radioisotope Generator

▫ Powerful generator currently being developed by NASA.

▫≥14 year lifetime ▫Mass ~ 20 kg▫Uses 0.8 kg plutonium-238▫ January 2015

Source: NASA

TestingTesting

• 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=kK4n5l7bHSw

TimelineTimeline

2017: Launch2024: LandThe goal is to land and test during winter in the Southern Hemisphere.

2017 2024

Cost of MissionCost of 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!

Bibliography

… is expensive but IMPORTANT!

The Search for Life