The planetary collision that created the Moon may have made life on Earth possible
The cosmic collision that formed the Moon may also have brought with it all the ingredients necessary for the origin of life on Earth. Scientists have not been able to determine exactly how and when elements such as carbon, nitrogen and sulfur ended up on our planet, but new research suggests they may have come from an object that hit Earth about 4.5 billion years ago.
The components thatore created the right conditions for the emergence of life on Earth, they may not have come from our planet. According to the new hypothesis, the basic elements of life were brought along with the planet, whichora collided with Earth. The very concept of planetary collision is not new. It is called the great collision theory and mowi that about 4.5 billion years ago a Mars-sized body struck the young Earth. The collision resulted in the formation of our Moon.
This hypothetical planet was called Thea and, according to scientists at Rice University in Texas, brought with it volatile elements such as carbon, nitrogen, wateror and sulfur, ktore enabled the emergence of life on Earth.
The findings appeared in the journal „Science Advances”.
Based on what we know, it is unlikely that Earth could have produced volatile substances, ktothat populated the atmosphere, hydrosphere and biosphere. – From the study of ancient meteoritesow scientists have long known that Earth and other rocky planets in the inner Solar System did not have such substances, said Rajdeep Dasgupta, cooroutor of the study. – But the timing and mechanism of obtaining these elementsow has long been the subject of heated discussions. The scenario we presented may explain the timing and source of theoThe source of these elementsoin a mannerob consistent with all the geochemical evidence – added.
It was long thought that volatiles on Earth were probably brought by meteorites called carbonaceous chondrites. These primitive meteorites, whichore have always bombarded our planet, they are much richer in volatiles than the early Earth. But the ratio of these substances in chondrites does not agree, the researchers say, especiallyoln the case of one pair of elementsow. The ratio of carbon to nitrogen in Earth’s silicate crust is more than 20 times higher than in carbonaceous chondrites. Therefore, another method of delivering these substances to Earth has been considered.
A group of scientistsow of Texas in her research used a series of high-temperature and high-pressure experimentsoin and simulations carried out in Dasgupta’s laboratory, ktory specializes in studying geochemical reactions occurring deep within the planet under conditions of intense heat and pressure.
The experiments were designed to test whether volatile elements – those with low boiling points – could have resulted from planetary collisions. Scientists wanted to test the idea that Earth’s volatiles arrived together planetary, whichora had a sulfur-rich nucleus.
The sulfur content of the planet’s core matters because of the puzzling collectiveor experimental evidenceoon carbon, nitrogen and sulfur, whichore found in all parts of the Earth other than the core. – The nucleus does not interact with the rest of the Earth, but everything above it, the mantle, crust, hydrosphere and atmosphere are connected and there are interactions between them, said study leader Damanveer Grewal.
In a series of experimentsoin a compositeoł scientistsow reproduced the conditions under whichorych could form the nucleus and outer layers of thei. This helped determine how much sulfur content the nucleus would have to have in order to exclude carbon and nitrogen from it, leaving much larger amounts of these elementsoin the outer layers of the planet.
Armed with this information, researchers have run about a billion computer simulations checking ros different scenarios to determine how theob Earth obtained its volatile components.
– We found that all the evidence – isotopic determinations, carbon/nitrogen ratios and total amounts of carbon, nitrogen and sulfur of Earth’s silicate crust – fit the hypothesis of a collision with a Mars-sized planet full of carbon and nitrogen and with a sulfur-rich core, resulting in aorej the birth of the moon – explained Grewal. Of course, this does not mean that chondrites have not influenced in some wayob on developingoj situation.
– It is likely that such an impactor roalso bringsosł water, another important volatile compound. Planets, ktore subjected to collisions, could have more chances to developoj life – noted Dasgupta.