Invisible Pink Unicorn writes: "Scientists analyzing data gathered by the Cassini spacecraft have confirmed the presence of heavy negative ions in the upper regions of Titan's atmosphere. These particles may act as organic building blocks for even more complicated molecules. This discovery was completely unexpected because of the chemical composition of the atmosphere, mainly consisting of nitrogen and methane. According to the lead researcher at the Mullard Space Science Laboratory, "Additional rings of carbon can build up on these ions, forming molecules called polycyclic aromatic hydrocarbons, which may act as a basis for the earliest forms of life." The article abstract is available from Geophysical Research Letters."