Titan (IMAGE) Faculty of Sciences of the University of Lisbon Caption The atmosphere of Saturn's largest moon hides its surface beneath a global layer of thick, opaque fogs. They are made up of organic molecules and hydrocarbons, “so large that they form particles, like the atmospheric pollution in some cities on Earth, and which are deposited on the surface”, says Rafael Silva, adding: “There could be even more interesting chemistry there.” Credit NASA/JPL-Caltech/Space Science Institute Usage Restrictions Attribution is required. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.