[meteorite-list] NASA Finds Hydrocarbons on Saturn's Moon Hyperion

[Ron Baalke]

http://www.jpl.nasa.gov/news/news.cfm?release=2007-071

NASA Finds Hydrocarbons on Saturn's Moon Hyperion
July 04, 2007 

PASADENA, Calif. - NASA's Cassini spacecraft has revealed for the first time 
surface details of Saturn's moon Hyperion, including cup-like craters filled 
with hydrocarbons that may indicate more widespread presence in our solar system 
of basic chemicals necessary for life. 

Hyperion yielded some of its secrets to the battery of instruments aboard C
assini as the spacecraft flew close by in September 2005. Water and carbon dioxide 
ices were found, as well as dark material that fits the spectral profile of 
hydrocarbons. 

A paper appearing in the July 5 issue of Nature reports details of Hyperion's 
surface craters and composition observed during this flyby, including keys to 
understanding the moon's origin and evolution over 4.5 billion years. This is the 
first time scientists were able to map the surface material on Hyperion. 

"Of special interest is the presence on Hyperion of hydrocarbons--combinations of 
carbon and hydrogen atoms that are found in comets, meteorites, and the dust in 
our galaxy," said Dale Cruikshank, a planetary scientist at NASA's Ames Research 
Center, Moffett Field, Calif., and the paper's lead author. "These molecules, when 
embedded in ice and exposed to ultraviolet light, form new molecules of biological 
significance. This doesn't mean that we have found life, but it is a further 
indication that the basic chemistry needed for life is widespread in the universe." 

Cassini's ultraviolet imaging spectrograph and visual and infrared mapping 
spectrometer captured compositional variations in Hyperion's surface. These 
instruments, capable of mapping mineral and chemical features of the moon, sent 
back data confirming the presence of frozen water found by earlier ground-based 
observations, but also discovered solid carbon dioxide (dry ice) mixed in 
unexpected ways with the ordinary ice. Images of the brightest regions of 
Hyperion's surface show frozen water that is crystalline in form, like that 
found on Earth. 

"Most of Hyperion's surface ice is a mix of frozen water and organic dust, but 
carbon dioxide ice is also prominent. The carbon dioxide is not pure, but is 
somehow chemically attached to other molecules," explained Cruikshank. 

Prior spacecraft data from other moons of Saturn, as well as Jupiter's moons 
Ganymede and Callisto, suggest that the carbon dioxide molecule is "complexed," 
or attached with other surface material in multiple ways. "We think that ordinary 
carbon dioxide will evaporate from Saturn's moons over long periods of time," 
said Cruikshank, "but it appears to be much more stable when it is attached to 
other molecules." 

"The Hyperion flyby was a fine example of Cassini's multi-wavelength capabilities. 
In this first-ever ultraviolet observation of Hyperion, the detection of water ice 
tells us about compositional differences of this bizarre body," said Amanda 
Hendrix, Cassini scientist on the ultraviolet imaging spectrograph at NASA's Jet 
Propulsion Laboratory, Pasadena, Calif. 

Hyperion, Saturn's eighth largest moon, has a chaotic spin and orbits Saturn every 
21 days. The July 5 issue of Nature also includes new findings from the imaging 
team about Hyperion's strange, spongy-looking appearance. Details are online at: 

http://ciclops.org/view.php?id=3303 . 

The Cassini-Huygens mission is a cooperative project of NASA, the European Space 
Agency and the Italian Space Agency. JPL, a division of the California Institute 
of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science 
Mission Directorate, Washington. 

More information on the Cassini mission is available at: 

http://www.nasa.gov/cassini . 

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Media contacts: Carolina Martinez 818-354-9382
Jet Propulsion Laboratory, Pasadena, Calif. 

Ruth Dasso Marlaire 650-604-4709
Ames Research Center, Moffett Field, Calif. 

2007-071