A large proportion of the substances that make the earth habitable apparently come from the outer solar system – including water, a new study shows.
London – When formed, the earth was hot, a sphere of red-hot rock. Over time, the planet cooled and became habitable. After all how did water and other elements necessary for life get on the planet? Researchers have been investigating this question for several years. So far, science has assumed that a large part of the water from asteroids or meteorite was brought to earth.
Now a research group from Imperial College London has taken a closer look at the composition of meteorites. The resulting study was in the journal Science released. A research team headed by Mark Rehkamper examined 18 meteorites of different origins for volatile substances. These are substances that change from the solid or liquid state to the gaseous state of aggregation at relatively low temperatures.
Research team examines meteorites for zinc
These include the six elements most commonly found in living organisms, but also water. “The addition of this material will have been important in the origin of life on Earth,” the study said in a statement. Specifically, the research team focused on the five different isotopes of zinc. They made a “zinc fingerprint” for each meteorite and compared it to samples from Earth to find out how much the materials from space contributed to the zinc deposits on Earth.
Rehkamper, Professor of Isotope Chemistry at Imperial College London and co-author of the study, explains: “Our data show that about half of the earth’s zinc deposits come from the outer solar system, from outside the orbit of Jupiter.” The expert emphasizes: “Based on our current models of the development of the early solar system, this was completely unexpected.”
Many volatiles on Earth come from the outer solar system
Before the study, researchers assumed that most of the volatiles on Earth came from asteroids that formed closer to Earth. According to the researchers, the new study reveals important clues as to how the very special conditions that make life possible came about on Earth.
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The research team also believes that material with a high concentration of zinc and other volatiles is also likely to be rich in water – which in turn provides clues as to where the water came from on Earth. “It appears that without the contribution of material from the outer solar system, Earth would have a much lower amount of volatile matter than we know it today – making it drier and possibly unable to support and support life.” ‘ emphasizes Rehkamper.
As a next step, the research team wants stones from Mars analyse, which is said to have housed water 4.1 to 3 billion years ago before it dried up. Also material from moon is on the analysis list of the research group. According to a popular theory, the moon was formed when a giant asteroid hit Earth about 4.5 billion years ago. By analyzing zinc isotopes in lunar rock, the research group hopes to find out what role the asteroid played in bringing water to Earth. (tab)
A meteorite is said to have hit and destroyed a house in the USA – but the US space agency Nasa is skeptical.
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