Joe the Aroma
2008-02-15 19:40:32 UTC
Saturn's orange moon Titan has hundreds of times more liquid hydrocarbons
than all the known oil and natural gas reserves on Earth, according to new
Cassini data. The hydrocarbons rain from the sky, collecting in vast
deposits that form lakes and dunes.
The new findings from the study led by Ralph Lorenz, Cassini radar team
member from the Johns Hopkins University Applied Physics Laboratory, USA,
are reported in the 29 January 2008 issue of the Geophysical Research
Letters.
"Titan is just covered in carbon-bearing material--it's a giant factory of
organic chemicals," said Lorenz. "This vast carbon inventory is an important
window into the geology and climate history of Titan."
At a balmy minus 179o C , Titan is a far cry from Earth. Instead of water,
liquid hydrocarbons in the form of methane and ethane are present on the
moon's surface, and tholins probably make up its dunes. The term 'tholins'
was coined by Carl Sagan in 1979 to describe the complex organic molecules
at the heart of prebiotic chemistry.
Cassini has mapped about 20% of Titan's surface with radar. Several hundred
lakes and seas have been observed, with each of several dozen estimated to
contain more hydrocarbon liquid than Earth's oil and gas reserves. The dark
dunes that run along the equator contain a volume of organics several
hundred times larger than Earth's coal reserves.
Proven reserves of natural gas on Earth total 130 thousand million tons,
enough to provide 300 times the amount of energy the entire United States
uses annually for residential heating, cooling and lighting. Dozens of
Titan's lakes individually have the equivalent of at least this much energy
in the form of methane and ethane.
"This global estimate is based mostly on views of the lakes in the northern
polar regions. We have assumed the south might be similar, but we really
don't yet know how much liquid is there," said Lorenz. Cassini's radar has
observed the south polar region only once, and only two small lakes were
visible. Future observations of that area are planned during Cassini's
proposed extended mission.
Scientists estimated Titan's lake depth by making some general assumptions
based on lakes on Earth. They took the average area and depth of lakes on
Earth, taking into account the nearby surroundings, like mountains. On
Earth, the lake depth is often 10 times less than the height of nearby
terrain.
"We also know that some lakes are more than 10 m or so deep because they
appear literally pitch-black to the radar. If they were shallow we'd see the
bottom, and we don't," said Lorenz.
The question of how much liquid is on the surface is an important one
because methane is a strong greenhouse gas on Titan as well as on Earth, but
there is much more of it on Titan. If all the observed liquid on Titan is
methane, it would only last a few million years, because as methane escapes
into Titan's atmosphere, it breaks down and escapes into space. If the
methane were to run out, Titan could become much colder. Scientists believe
that methane might be supplied to the atmosphere by venting from the
interior in cryovolcanic eruptions. If so, the amount of methane, and the
temperature on Titan, may have fluctuated dramatically in Titan's past.
"We are carbon-based life, and understanding how far along the chain of
complexity towards life that chemistry can go in an environment like Titan
will be important in understanding the origins of life throughout the
universe," added Lorenz.
Cassini's next radar flyby of Titan is on 22 February 2008, when the radar
instrument will observe the landing site of ESA's Huygens probe.
Notes for editors:
The Cassini-Huygens mission is a cooperative project of NASA, ESA and the
Italian Space Agency (ASI).
The Jet Propulsion Laboratory (JPL), a division of the California Institute
of Technology, manages the Cassini-Huygens mission for NASA's Science
Mission Directorate. JPL designed, developed and assembled the Cassini
orbiter. ESA developed the Huygens Titan probe, while ASI managed the
development of the high-gain antenna and the other instruments of its
participation. The radar instrument was built by JPL and the Italian Space
Agency, working with team members from the United States and several
European countries.
http://www.spaceref.com/news/viewpr.html?pid=24757
than all the known oil and natural gas reserves on Earth, according to new
Cassini data. The hydrocarbons rain from the sky, collecting in vast
deposits that form lakes and dunes.
The new findings from the study led by Ralph Lorenz, Cassini radar team
member from the Johns Hopkins University Applied Physics Laboratory, USA,
are reported in the 29 January 2008 issue of the Geophysical Research
Letters.
"Titan is just covered in carbon-bearing material--it's a giant factory of
organic chemicals," said Lorenz. "This vast carbon inventory is an important
window into the geology and climate history of Titan."
At a balmy minus 179o C , Titan is a far cry from Earth. Instead of water,
liquid hydrocarbons in the form of methane and ethane are present on the
moon's surface, and tholins probably make up its dunes. The term 'tholins'
was coined by Carl Sagan in 1979 to describe the complex organic molecules
at the heart of prebiotic chemistry.
Cassini has mapped about 20% of Titan's surface with radar. Several hundred
lakes and seas have been observed, with each of several dozen estimated to
contain more hydrocarbon liquid than Earth's oil and gas reserves. The dark
dunes that run along the equator contain a volume of organics several
hundred times larger than Earth's coal reserves.
Proven reserves of natural gas on Earth total 130 thousand million tons,
enough to provide 300 times the amount of energy the entire United States
uses annually for residential heating, cooling and lighting. Dozens of
Titan's lakes individually have the equivalent of at least this much energy
in the form of methane and ethane.
"This global estimate is based mostly on views of the lakes in the northern
polar regions. We have assumed the south might be similar, but we really
don't yet know how much liquid is there," said Lorenz. Cassini's radar has
observed the south polar region only once, and only two small lakes were
visible. Future observations of that area are planned during Cassini's
proposed extended mission.
Scientists estimated Titan's lake depth by making some general assumptions
based on lakes on Earth. They took the average area and depth of lakes on
Earth, taking into account the nearby surroundings, like mountains. On
Earth, the lake depth is often 10 times less than the height of nearby
terrain.
"We also know that some lakes are more than 10 m or so deep because they
appear literally pitch-black to the radar. If they were shallow we'd see the
bottom, and we don't," said Lorenz.
The question of how much liquid is on the surface is an important one
because methane is a strong greenhouse gas on Titan as well as on Earth, but
there is much more of it on Titan. If all the observed liquid on Titan is
methane, it would only last a few million years, because as methane escapes
into Titan's atmosphere, it breaks down and escapes into space. If the
methane were to run out, Titan could become much colder. Scientists believe
that methane might be supplied to the atmosphere by venting from the
interior in cryovolcanic eruptions. If so, the amount of methane, and the
temperature on Titan, may have fluctuated dramatically in Titan's past.
"We are carbon-based life, and understanding how far along the chain of
complexity towards life that chemistry can go in an environment like Titan
will be important in understanding the origins of life throughout the
universe," added Lorenz.
Cassini's next radar flyby of Titan is on 22 February 2008, when the radar
instrument will observe the landing site of ESA's Huygens probe.
Notes for editors:
The Cassini-Huygens mission is a cooperative project of NASA, ESA and the
Italian Space Agency (ASI).
The Jet Propulsion Laboratory (JPL), a division of the California Institute
of Technology, manages the Cassini-Huygens mission for NASA's Science
Mission Directorate. JPL designed, developed and assembled the Cassini
orbiter. ESA developed the Huygens Titan probe, while ASI managed the
development of the high-gain antenna and the other instruments of its
participation. The radar instrument was built by JPL and the Italian Space
Agency, working with team members from the United States and several
European countries.
http://www.spaceref.com/news/viewpr.html?pid=24757
--
Joseph The Aroma III
Joseph The Aroma III