Rain Reveals Ancient Fossils Earth's Atmosphere

Not only bones that could be fossilized. More recently, scientists have observed a trace of rain that became fossilized.

Rain that occurred approximately 2.7 billion years ago and is printed on the ancient stones in South Africa. Traces of ancient rain gives clues about the initial conditions of the Earth's atmosphere.

In the ancient times, the sun shines 30 percent more dim. The atmosphere is much colder than now, and indicate that the Earth in a frozen state.

The scientists also say that the atmosphere is thicker and has a greenhouse gas concentrations are high. Primitive atmosphere full of greenhouse gases to help warm the Earth.

"Because the sun was much dimmer, the Earth will freeze if it has the same atmospheric conditions at this time," said Sanjoy Som, researchers at NASA Ames Research Center.

In addition, the study also compared the speed of falling rain with rain early in the present. At present, a rain drop to approximately one-quarter inch size. Speed ​​of fall of approximately nine meters per second.

A thicker atmosphere in ancient times, lead to greater resistance to rain. Speed ​​of the fall so more slowly. This means that the grain size similar to the one i hujna present, will form a smaller footprint.

Based on the footprint size, the researchers could say that the ancient atmosphere that creates rain, less than two-fold thicker than in the present.