Titan's inventory of organic surface materials
Article first published online: 29 JAN 2008
Copyright 2008 by the American Geophysical Union.
Geophysical Research Letters
Volume 35, Issue 2, January 2008
How to Cite
2008), Titan's inventory of organic surface materials, Geophys. Res. Lett., 35, L02206, doi:10.1029/2007GL032118., et al. (
- Issue published online: 29 JAN 2008
- Article first published online: 29 JAN 2008
- Manuscript Accepted: 26 NOV 2007
- Manuscript Revised: 18 NOV 2007
- Manuscript Received: 2 OCT 2007
 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 × 104 km3 of liquid, and >2 × 105 km3 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.