Search for life on Titan. David Shalloway, Cornell University. David Livingston, SpaceShow.com

Sep 25, 2017, 01:17 AM

AUTHOR (Photo: Near-infrared radiation from the Sun reflecting off Titan's hydrocarbon seas) http://JohnBatchelorShow.com/contact http://JohnBatchelorShow.com/schedules http://johnbatchelorshow.com/blog Twitter: @BatchelorShow

Search for life on Titan. David Shalloway, Cornell University. David Livingston, SpaceShow.com

“Titan is the only place in the solar system, except Earth, where rainfall and seasonally flowing liquids erode the landscape. Whereas the surface pressure is similar to that of Earth, the temperature is extremely low and the dominant liquids are methane and ethane. This makes Titan a test case for exploring the environmental limits of prebiotic chemistry and addressing the question of whether life can develop without water. Experimental and observational data suggest that hydrogen cyanide, the most abundant hydrogen-bonding molecule in Titan’s atmosphere, may polymerize on the surface to polyimine. Using quantum mechanical calculations, we show that polyimine has interesting electronic and structural properties that could potentially facilitate prebiotic chemistry under cryogenic conditions akin to those on Titan.”


  1. Hypothesis: "Titan is the only place in the solar system, except Earth, where rainfall and seasonally flowing liquids erode the landscape. Whereas the surface pressure is similar to that of Earth, the temperature is extremely low and the dominant liquids are methane and ethane. This makes Titan a test case for exploring the environmental limits of prebiotic chemistry and addressing the question of whether life can develop without water. Experimental and observational data suggest that hydrogen cyanide, the most abundant hydrogen-bonding molecule in Titan’s atmosphere, may polymerize on the surface to polyimine. Using quantum mechanical calculations, we show that polyimine has interesting electronic and structural properties that could potentially facilitate prebiotic chemistry under cryogenic conditions akin to those on Titan.

  2. Without water, what else can build? "Saturn’s moon Titan is a carbon-rich, oxygen-poor world with a wide range of organic compounds, atmospheric energy sources, and alkane liquid seas—all measured by the remarkably successful Cassini–Huygens mission (1). The extreme cold puts liquid water out of reach—buried 50–100 km below a frigid ice crust (2). The lack of liquid water and presence of liquid hydrocarbons makes Titan a unique “natural laboratory” for exploring potential nonterrestrial forms of prebiotic chemistry or, more speculatively, biochemistry, whose essential biopolymers would differ profoundly from terrestrial ones (3). Regardless of the specific chemistry involved, life requires polymorphic molecules that combine flexibility with the ability to form the organized metastable structures needed for function, adaptation, and evolution. This, almost certainly, requires extended molecules capable of intermolecular and intramolecular hydrogen bonding, but such bonds need not involve oxygen; nitrogen is a potential surrogate. Although =N–H…N bonds are weaker than those involving oxygen, their energies are large compared with thermal energy (kT ∼ 0.18 kcal/mol at Titan’s low temperature, 90–94 K) and intermolecular and intramolecular bonds need not compete with the strong –O–H…O hydrogen bonds in water, as on Earth. Thus, they might provide the needed balance between rigidity and polymorphism

  3. What is a polyimine? Why is it critical? "The chemistry of hydrogen cyanide (HCN) is believed to be central to the origin of life question. Contradictions between Cassini–Huygens mission measurements of the atmosphere and the surface of Saturn’s moon Titan suggest that HCN-based polymers may have formed on the surface from products of atmospheric chemistry. This makes Titan a valuable “natural laboratory” for exploring potential nonterrestrial forms of prebiotic chemistry. We have used theoretical calculations to investigate the chain conformations of ...