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Titan's inventory of organic surface materials
Author(s) -
Lorenz Ralph D.,
Mitchell Karl L.,
Kirk Randolph L.,
Hayes Alexander G.,
Aharonson Oded,
Zebker Howard A.,
Paillou Phillipe,
Radebaugh Jani,
Lunine Jonathan I.,
Janssen Michael A.,
Wall Stephen D.,
Lopes Rosaly M.,
Stiles Bryan,
Ostro Steve,
Mitri Giuseppe,
Stofan Ellen R.
Publication year - 2008
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2007gl032118
Subject(s) - titan (rocket family) , impact crater , methane , ejecta , astrobiology , geology , environmental science , oil sands , earth science , solar system , atmospheric sciences , physical geography , chemistry , materials science , physics , organic chemistry , asphalt , quantum mechanics , supernova , geography , composite material
Cassini RADAR observations now permit an initial assessment of the inventory of two classes, presumed to be organic, of Titan surface materials: polar lake liquids and equatorial dune sands. Several hundred lakes or seas have been observed, of which dozens are each estimated to contain more hydrocarbon liquid than the entire known oil and gas reserves on Earth. Dark dunes cover some 20% of Titan's surface, and comprise a volume of material several hundred times larger than Earth's coal reserves. Overall, however, the identified surface inventories (>3 × 10 4 km 3 of liquid, and >2 × 10 5 km 3 of dune sands) are small compared with estimated photochemical production on Titan over the age of the solar system. The sand volume is too large to be accounted for simply by erosion in observed river channels or ejecta from observed impact craters. The lakes are adequate in extent to buffer atmospheric methane against photolysis in the short term, but do not contain enough methane to sustain the atmosphere over geologic time. Unless frequent resupply from the interior buffers this greenhouse gas at exactly the right rate, dramatic climate change on Titan is likely in its past, present and future.