Thursday, March 29, 2012

Origin of life on Earth, revealed new experiences

Scientists have found new evidence that serve to elucidate a long-sought mystery: who was the source of life on our planet.
Research confirms that life on Earth is due to comets that bombarded our planet billions of years ago, storing essential ingredients for his appearance here.
Jennifer G. Blank, coordinator of the research team, described experiments in the laboratory with powerful tools and computer models. Scientists have recreated the conditions inside comets when they hit Earth's atmosphere at a speed of about 40,000 km / h, and then crashing the surface.

The research is part of a broad scientific effort that has the goal to understand how amino acids and other ingredients necessary for life on our planet have been stored in several billion years ago. Before then, Earth was a barren and desolate planet. Amino acids are the key ingredient of proteins, "brick" core of all life, from microbes to humans.
"Our research shows that the key to life would have remained intact despite massive shock wave created by comet impact," said Blank.

"Comets are an ideal body for delivering the necessary ingredients for chemical evolution that led to life. This scenario is ideal, because it includes all the ingredients of life: amino acids, water and energy, "added Blank.
Comets are composed of frozen gases, water, ice, dust and rock. These bodies can measure 15 km in diameter or more. Comets orbit the sun in a belt located a long distance of planets in the solar system. Periodically, some comets can escape from this place, becoming visible in the sky.

A few billion years, many comets and asteroids bombarded Earth, craters on the Moon are evidence of this event.

Scientific evidence suggests that life on Earth began at the end of a period is now over 3.8 billion years after Earth was bombarded by asteroids and comets. Before then, Earth was too hot to support life forms. The oldest fossils that provide evidence of life dates back 3.5 billion years ago.

Analysis of samples collected by NASA comet probe confirmed that they contain amino acids. Now, experiments by Blank and colleagues in a NASA research center showed that amino acids were able to withstand impact with Earth. In the experiment, scientists have found that amino acids began to form peptide bonds, the first step towards forming proteins.
Blank said it is likely that over the years have held several events to "delivery" of the essential elements for life on earth were brought to our planet by comets, asteroids and meteorites.
Evidence has been presented of the 243-meeting of the American Chemical Society, the world's largest scientific society that was founded in 1876.

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