A team of scientists from the US and the UK has developed a technique using ultraviolet light to identify organic matter in soils that could be used to find life on Mars. Chemical compounds called polycyclic aromatic hydrocarbons (PAHs), often are found on comets, meteorites and in space between the stars, and are considered candidates for being one of the earliest forms of organic matter in the universe. Like living organisms, these molecules fluoresce when excited by ultraviolet light, making them an ideal target for using this new technology.