Our Life Began On Earth Due To A Young Sun's 'Super-Flares'

Life started with a young sun as well as its flares, which were strong, like a thousand trillion exploding atomic bombs. They were sent crashing into the earth about four billion years ago.

The sun was a cool dude in those days, yet continuous super-flares threw nitrogen (N2) molecules into the earth's atmosphere and led to the creation of nitrous oxide (N2O) and hydrogen cyanide, which in turn led to the building up of amino acids---the building blocks of proteins, and life.

At the time, the nitrogen in the atmosphere of primordial Earth was non-reactive and had to be converted into forms that could be accessed to create life. It could happen if the temperatures were high.

Scientists conducted a telescopic observation of stars resembling the sun in the first few hundred million years of its life. They then blended these results with models of the chemistry of the air in primordial Earth.

Without greenhouse gases that could trap the sun's heat, the earth would have been icy cold. Yet, four million years ago, it became a wet, warm planet supporting life, mainly due to the N2O created by the sun's flares.

"Our model describes the 'cosmic' ingredient required to produce biological molecules of life," said Vladimir Airapetian of George Mason University and co-author of the study, adding that other planets that experienced similar events probably had similar outcomes.

"Geologic evidence suggests that Mars was also paradoxically warm and wet around the same time," said Ramses Ramirez of the Carl Sagan Institute who was not involved in the study. "The findings may have implications for the climates and potential biology of terrestrial exoplanets orbiting very young Sun-like stars, particularly stars with exceptionally high magnetic fluxes and very intense super stellar storms."

The findings were published in the May 23 issue of Nature Geoscience.