Planet haze may have spawned organics

Back when life on Earth was just beginning, photochemistry in the atmosphere may have supplied key organic materials to the planet's surface and allowed life to flourish, according to Margaret A. Tolbert of the University of Colorado, Boulder, and her colleagues (Proc. Natl. Acad. Sci. USA, DOI: 10.1073/pnas.0608561103). The finding comes from a study initially designed to look at the atmospheric haze surrounding Saturn's moon Titan. But the researchers realized their approach also could be applied to a similar organic haze that might have existed on early Earth. They used a UV lamp to irradiate simulated atmospheres of CH₄ and N₂ for Titan and CH₄ and CO₂ for early Earth and then analyzed the products by aerosol mass spectrometry. Both simulations generated various hydrocarbons, including aldehydes and ethers for the early-Earth model. Photolysis of CH₄ and CO₂ may have created significant amounts of organic compounds that could have rained on Earth's surface, the researchers conclude.