Early Life Fed on Organic Haze, Study Suggests

A haze of atmospheric chemicals similar to those now found on Saturn's giant moon Titan might have been a major source of food for ancient life on Earth, a new study suggests.

Scientists have long been fascinated with Titan, which is shrouded by a murky orange atmosphere of smog-like chemicals created as sunlight interacts with methane high above the surface.

This thick haze completely shrouds Titan, so all you can see in the photographs is orange, said Margaret Tolbert, a chemist at the University of Colorado at Boulder and a study co-author.

Tolbert's team wondered if similar chemicals might have formed in early Earth's atmosphere, which at various times also contained methane. So they mixed methane and carbon dioxide—a major constituent of the Earth's primordial atmosphere—in a reaction chamber and exposed it to simulated sunlight.

Researchers had previously thought that carbon dioxide—which is not present in Titan's atmosphere—would stifle the reactions that produce complex molecules.