Saturns Moons

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Saturns Moons

• How Titan, Enceladus, Mimas, and Iapetus have
  changed our understanding of Life in outer space

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Relative Sizes of Saturns moons
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About Saturn

• In July of 1610, Galileo observed the rings of a
  planet more recognizable than any other in our
  solar system Saturn.
• Saturn, a gas giant, is composed of hydrogen,
  with small proportions of helium and trace
  elements. The interior consists of a small core
  of rock and ice, surrounded by a thick layer of
  metallic hydrogen and a gaseous outer layer.
• Wind speeds on Saturn can reach 1800 km/h, and
  the planetary magnetic field is intermediate in
  strength between that of Earth and the more
  powerful field around Jupiter.

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About Saturn

• Approximately 9.53 AU away from the sun, Saturn
  is the home to more than 60 moons and many rings
  consisting of ice particles, rocks and dust.
• Among the 60 planets, the moon Titan stands out
  as the second largest moon in the solar system.
  It also is the only moon that possesses an
  atmosphere.
• The sister moons Mimas, Enceladus, Tethys, Rhea
  and Iapetus are equally breathtaking and
  scientifically intriguing.
• This slide show involves scientific discussions
  on the possibility of life on these moons.

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Saturn Fast Facts
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Titan
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Possibility of liquid between Titans outer layer
and core

• Fluctuations in length of Titan day
• Movement of land masses on surface
• Lake of liquid hydrocarbons discovered on Surface
• Observed as only known body to contain liquid on
  surface other than Earth
• Is effected by greenhouse gases
• This is the first observation that really pins
  down that Titan has a surface lake filled with
  liquid, said Bob Brown of the University of
  Arizona, Tucson. Brown is the team leader of
  Cassini's visual and mapping instrument.
• "We know the lake is liquid because it reflects
  essentially no light at 5-micron wavelengths,"
  Brown said. "It was hard for us to accept the
  fact that the feature was so black when we first
  saw it. More than 99.9 percent of the light that
  reaches the lake never gets out again. For it to
  be that dark, the surface has to be extremely
  quiescent, mirror smooth. No naturally produced
  solid could be that smooth."

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Lake Ontario Lacus

• Lake Ontario Lacus was discovered on Titans
  south polar region
• Lake approximately 20,000 km2 (size of Lake
  Ontario)

• - Ethane present in liquid form when mixed in
  solution with methane and other hydrocarbons and
  nitrogen at approximately 88.7 K
• Since this solution can exist as both liquid and
  gas, there is overwhelming evidence of
  evaporation, rain, and fluid carved channels on
  Titans surface
• NOTE C2H6 and CH4 alone are not sufficient
  conditions for life as they are not nearly as
  soluble as H2O

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Because of extremely low surface temperatures
(93.7 K) all water is in two states liquid, gas
When a sufficient amount of heat is added, ice
melts into water.
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Enceladus
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Atmosphere bends magnetic field of Saturn

• Although the atmosphere is very thin it is
  detectable partially because it distorts the
  magnetic field produced by Saturn

• - Moon too small to maintain atmosphere
• - Moon loses 125kg/s of water to space
• Geysers or volcanoes must continuously replenish
  water
• Once new geysers are discovered and existence of
  liquid water is proven, Enceladus may prove to be
  more habitable than Europa
• Radiation belts surrounding Jupiter add more
  ecological stress on Europa

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Water vapor released through volcanoes or geysers
- Very thin atmosphere containing water vapor,
nitrogen, carbon dioxide, and methane
- Water geysers on surface of Enceladus release
water vapor into atmosphere
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Icy tracks show signs of liquid rivers

• Plumes vent from tiger-stripes on surface
  ranging over 100km in length
• Surface temperature within cracks 10-17 C warmer
  than surrounding areas

• Possible causes of venting
• Decay of radioactive material within core
• Tidal forces caused by pull of Saturn
• Tidal forces caused by big sister moon Dione

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Other Moons of Saturn
Hyperion
Dione
Phoebe
Epithemeus
Rhea
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S-2005 S1
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Mimas Fast Facts
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Why Mimas Matters

• Because of Mimass low density (1.17 g/cm3, it is
  mostly composed of water (ice), and only a small
  amount of rock.
• Although Mimas has no strong atmosphere, bulges
  and cracks on the surface suggests trapped gases.
• Mimas is riddled with craters and cracks, hinting
  that vast amount of gas has already escaped. Yet
  the south pole region remains intact, and hence,
  could contains more chemical matter.
• Because of tidal forces on Mimas, it is not
  completely spherical.

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Crater of Mimas

• Mimass most Distinct character is a crater 130
  km across and 6 km deep. It is known as Herschel.
  
• The damage of the impact can be seen on the
  other side of the crater too, making Mimas one of
  the most hostile environments on a moon in our
  solar system.
• Due to its unique look, Mimas resembles Death
  Star from Star wars.

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Iapetus Fast Facts
Iapetus lit by light reflected off of Saturn.
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The Two-faced Moon

• Iapetus has two sides the side facing Saturn is
  dark as charcoal, and the opposite side is white
  as snow.
• Thermal segregation model explains moons
  two-toned appearance.
• Infrared vision shows the dark side of the moon
  is warm enough to release small amounts of water
  vapor.
• The vapor travels to the bright and colder
  regions of the moon and condenses because of
  Saturns magnetic field.
• Hence, the darker side loses its surface
  material, gets thinner, and gets darker. The
  bright regions accumulate more ice and gets
  brighter.

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The Two-faced Moon (contd.)

• The equatorial mountain range (12 miles high)
  gives Iapetus the shape of a walnut.
• The bulge occurs because of trapped gases in
  under the surface.
• Signs of release of water vapor, hydrogen gas,
  and other hydrogen compounds hints moons active
  ecological state.
• To be in its current tidally locked state of
  orbit, scientists suggest Iapetus must have
  heated up by the radioactive decay of
  aluminum-26.
• It explains how it would have helped cool the
  moon fast enough to preserve the equatorial bulge
  and yet be plastic enough to be affected by
  Saturns tidal current.

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Iapetus Pictures
The Dark Region on the surface of Iapetus shows a
possibility of liquid or frozen lakes. This area
resides amongst the hilly regions near the
equator. This image of one of the hilly regions
displays the patchy surface of Iapetus due to a
depression underground from constantly stirring
gases.
The background picture is a flat region of
Iapetus. The dark patches are an unknown
materials splattered across the frozen plains .
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Conclusion

• Thus, studying our solar system helps define our
  planet better in terms of its origin, or its
  future state.
• Saturn and its moons help us understand the basic
  necessities of habitable life. We can reasonably
  imagine another earth in outer space.
• The planets and moons of our solar system are
  essential stepping stones towards such a profound
  discovery.

Artist depiction of another earth
By Sean Bennett and Saahil Patel