Billions of years ago, Earth may have been shrouded in a blanket of atmospheric haze like that seen on Saturn’s moon Titan, providing organic material that nourished our planet’s earliest life forms, researchers said. Some scientists look to Titan as a model for what early Earth’s atmosphere may have looked like.
They think Titan’s atmosphere, packed with organic aerosol particles created when sunlight reacts with methane gas, may offer clues about Earth’s climate when primitive organisms were first arising 3.6 billion years ago.
University of Colorado scientist Margaret Tolbert and her colleagues conducted laboratory experiments based on conditions in Titan’s atmosphere measured last year by the Huygens space probe during the Cassini mission.
Earth was formed perhaps 4.6 billion years ago and liquid water was present about 3.8 billion years ago. Tolbert said that this haze may have been a dominant feature of Earth’s early atmospheric landscape from about the time of the first evidence of life 3.6 billion years ago until the rise of the oxygen content about 2.3 billion years ago.
Tolbert said the chemical composition of the haze was organic molecules that are digestible to organisms alive today and could have nourished simple living organisms along ago.