Titan Chemistry Science Daily Website

Titan

Chemistry

Science Daily website article review: Titan's atmosphere

According to the 2009 Science Daily website article "Chemistry of Titan's hazy atmosphere unraveled," Saturn's moon Titan has long been regarded as unique by scientists because it is the only object in the solar system "besides Venus and Earth with a solid surface and thick atmosphere" despite its remote location in the outreaches of our solar system (Chemistry, 2009, Science Daily). Until recently, the reasons for the appearance of Titan's atmosphere were elusive. Now, scientists have been able to simulate the conditions of the molecular collisions that take place in Titan's atmosphere through the use of new technology and calculations.

University of Hawaii researchers have discovered that "an ethynyl radical is produced in Titan's atmosphere by the photodissociation of acetylene by ultraviolet light. Photodissociation is a process in which a chemical compound is broken down by photons" (Chemistry, 2009, Science Daily). This stimulates the creation of triacetylene, which serves as a building block to form more complex and longer polyynes and produces "potential precursors for the aerosol-based layers of haze surrounding Titan" (Chemistry, 2009, Science Daily).

Triacetylene and diacetylene are molecules "consisting of six and four carbon atoms, respectively, and two hydrogen atoms. The atoms in each molecule are connected by alternating single and triple bonds" (About that, 2009, Scientific Blogging). Ethynyl is a highly reactive substance. It is made of two carbon atoms connected by a triple bond and one hydrogen atom connected by a single bond. A single electron on the exterior carbon atom gives ethynyl the impetus to "attack" other molecules (About that, 2009, Scientific Blogging). Thus triacetylene is formed in a chemical process whereby the radical present in the ethynyl molecule and a diacetylene molecule collide. Diacetylene must come into contact with ethynyl to produce the haze of Titian's atmosphere. The temperatures on Saturn, which average in the range of -99 F. To -290 F, or -73 C. To -179 C, mean that ethynyl's highly reactive status is necessary to perform the chemical process that results in the creation of triacetylene and the polyynes that serve as ultraviolet radiation shields and appear as haze from a distance (About that, 2009, Scientific Blogging). Saturn is otherwise too cold to have the heat to propel chemical reactions, in the absence of reactive molecules like ethynyl.