Forming complex organic molecules on Titan

摘要

Researchers have found a series of chemical reactions that likely formed the large, organic molecules that compose the thick, hazy, orange atmosphere of Saturn's moon Titan. The research demonstrates a mechanism to describe how Titan's atmosphere creates complex molecules. Xibin Gu et al. studied the formation of triacetylene and larger organic molecules in the lab and in simulations. The authors found that triacetylene can be formed by collisions between ethynyl radicals and di-acetylene. The reaction was easy to initiate and energetically favorable under the conditions found in Titan's atmosphere. The authors suggest that triacetylene may serve as the primary building block for creating more complex polyynes. These organic molecules may act as a shield to ultraviolet radiation, much like Earth's ozone layer. An improved understanding of the chemical elements and dynamics of Titan's atmosphere could provide clues to the origins and chemical dynamics of Earth's early atmospheres and how their evolution affected the development of life, according to the authors.