Planet Crash That Made Moon Left Key Elements For Life On Earth, Scientists Say
vendredi 25 janvier 2019, 08:00 , par Slashdot
Scientists are claiming the cosmic collision that made the moon left a host of elements behind on Earth that were crucial for life to emerge. The Guardian reports: The impact 4.4 billion years ago is thought to have occurred when an itinerant planet the size of Mars slammed into the fledgling Earth, scattering a shower of rocks into space. The debris later coalesced into the moon. Beyond an act that shaped the sky, the smash-up transferred essential elements to the Earth's surface, meaning that most of the carbon and nitrogen that makes up our bodies probably came from the passing planet, the researchers believe.
Petrologists at Rice University in Texas reached their conclusions after running experiments on geochemical reactions under the high temperatures and pressures found deep inside a planet. They wanted to understand whether Earth acquired key elements from meteorites that slammed into Earth or through some other ancient route. Lead author Damanveer Grewal found that a planet with a sulphur-rich core would have large fractions of carbon and nitrogen on its surface. Such a planet could transfer that volatile material to Earth in just the right proportions if it happened to clatter into it, the researchers found, after modeling a billion different cosmic scenarios in a computer and comparing them to conditions seen in the solar system today. The research is published in Science Advances.
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mar. 17 sept. - 00:14 CEST