ALMA detection and astrobiological potential of vinyl cyanide on Titan.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 28782019.
- Also identified by DOI 10.1126/sciadv.1700022 and PMC identifier 5533535.
- Licence recorded as CC BY-NC.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Recent simulations have indicated that vinyl cyanide is the best candidate molecule for the formation of cell membranes/vesicle structures in Titan's hydrocarbon-rich lakes and seas. Although the existence of vinyl cyanide (C<sub>2</sub>H<sub>3</sub>CN) on Titan was previously inferred using Cassini mass spectrometry, a definitive detection has been lacking until now. We report the first spectroscopic detection of vinyl cyanide in Titan's atmosphere, obtained using archival data from the Atacama Large Millimeter/submillimeter Array (ALMA), collected from February to May 2014. We detect the three strongest rotational lines of C<sub>2</sub>H<sub>3</sub>CN in the frequency range of 230 to 232 GHz, each with >4σ confidence. Radiative transfer modeling suggests that most of the C<sub>2</sub>H<sub>3</sub>CN emission originates at altitudes of ≳200 km, in agreement with recent photochemical models. The vertical column densities implied by our best-fitting models lie in the range of 3.7 × 10<sup>13</sup> to 1.4 × 10<sup>14</sup> cm<sup>-2</sup>. The corresponding production rate of vinyl cyanide and its saturation mole fraction imply the availability of sufficient dissolved material to form ~10<sup>7</sup> cell membranes/cm<sup>3</sup> in Titan's sea Ligeia Mare.