The ingredients that created the conditions for life on Earth might not be native to our planet, Earth. According to a new hypothesis published in the journal Science Advances , the essential elements for life were incorporated into a planet the size of Mars that collided with Earth 4.5 billion years ago.
This hypothetical planet is called Tea , and some experts believe that it is also responsible for breaking a portion of the Earth and sending it at full speed into space and it will end up becoming our Moon.
But, according to researchers at Rice University in Houston (USA), it brought with it volatile elements such as carbon, nitrogen, hydrogen and sulfur, which allowed the Earth to come to life.
From what we know, the Earth is unlikely to have produced those volatile substances that feed the atmosphere, hydrosphere, and biosphere on its own.
For a long time it was thought that the volatile elements were transported Earth in meteorites perhaps called carbonaceous chondrites -meteoritos s not METALICOS. These early meteorites that bombarded our planet are much richer in volatile compounds than early Earth (also known as Gaia) and other rocky bodies in the inner solar system, which lends more weight to this hypothesis.
However, the carbon-nitrogen ratio of the silicate mass by mass is more than 20 times the ratio observed in carbonaceous chondrites, so the scientists wanted to find out if the volatiles could have been delivered to Earth via another method, like the planet Tea.
In a series of hands-on experiments using silicate-filled capsules and alloy mixtures, the team recreated the high-temperature, high-pressure conditions under which the core of Tea could have formed. This helped determine by what percentage of sulfur the core might have excluded carbon and nitrogen, leaving them in the planet’s bulk silicate.
Using all the data , the team ran computer simulations of about a billion different scenarios to determine how the Earth got its volatile compounds.
“What we found is that all the evidence – isotopic signatures, the carbon-nitrogen ratio, and the overall amounts of carbon, nitrogen, and sulfur in Earth’s silicate – was consistent with a moon-forming impact involving a planet from the size of Mars with a nucleus rich in sulfur “, commented Damanveer Grewal, co-author of the work.
This doesn’t mean that carbonaceous chondrites weren’t contributing in any way, but it does indicate that Tea may have assisted with the majority, a finding that suggests a planet may have a better chance of developing life if it undergoes violent collisions.
“Since studying early meteorites, scientists have long known that Earth and other rocky planets in the inner solar system are depleted by volatility,” explained geologist Rajdeep Dasgupta.
“But the timing and mechanism of volatile delivery has been hotly debated. Ours is the first scenario that can explain timing and delivery consistently with all geochemical evidence ,” concludes Dasgupta.
Referencia: D.S. Grewal el al., “Delivery of carbon, nitrogen, and sulfur to the silicate Earth by a giant impact,” Science Advances (2019). DOI: 10.1126/sciadv.aau3669 , http://advances.sciencemag.org/content/5/1/eaau3669
