ALMA detection and astrobiological potential of vinyl cyanide on Titan

• DOI: 10.1126/sciadv.1700022
• Publication Date: 2017-07-29T01:00:29Z
• Authors: Maureen Y. Palmer; Martin A. Cordiner; Conor A. Nixon; Steven B. Charnley; Nicholas A. Teanby; Zbigniew Kisiel; Patrick G. J. Irwin; Michael J. Mumma
• Keywords: 13. Climate action; 0103 physical sciences; 540; 01 natural sciences; Research Articles; 620

Recent simulations have indicated that vinyl cyanide is the best candidate molecule for formation of cell membranes/vesicle structures in Titan's hydrocarbon-rich lakes and seas. Although existence (C2H3CN) on Titan was previously inferred using Cassini mass spectrometry, a definitive detection has been lacking until now. We report first spectroscopic atmosphere, obtained archival data from Atacama Large Millimeter/submillimeter Array (ALMA), collected February to May 2014. detect three strongest rotational lines C2H3CN frequency range 230 232 GHz, each with >4σ confidence. Radiative transfer modeling suggests most emission originates at altitudes ≳200 km, agreement recent photochemical models. The vertical column densities implied by our best-fitting models lie 3.7 × 1013 1.4 1014 cm-2. corresponding production rate its saturation mole fraction imply availability sufficient dissolved material form ~107 membranes/cm3 sea Ligeia Mare.