Most of the essential elements of life would have arrived on Earth as a result of the global collision that led to the creation of the Moon more than 4.4 billion years ago, say US petrologists.
According to the generally accepted theory, the Earth’s natural satellite would be born as a result of a huge collision between our planet and a celestial object the size of Mars shortly after the formation of the solar system. This shock would have torn off some of the Earth’s material, which later would have agglomerated to form our satellite.
At the origin of life
The American researcher Rajdeep Dasgupta and his colleagues at Rice University believe that this cataclysmic event is also at the origin of the presence on Earth of a large amount of carbon, nitrogen and other volatile organic compounds essential to the environment. appearance of life.
In fact, these scientists wanted to test the validity of the idea that these compounds reached the Earth as a result of a collision with an embryonic planet with a sulfur-rich nucleus.
“The study of primitive meteorites has shown that the Earth and the other rocky planets of the inner solar system are poor in volatile organic compounds. The timing and manner of their arrival on Earth are still debated, “says Professor Dasgupta.
Our scenario is the first to explain the presence of these compounds on Earth in a manner compatible with all the geochemical evidence we have.
A scenario tested in the laboratory
The evidence was gathered from a combination of high-temperature and high-pressure experiments conducted in Dr. Dasgupta’s laboratory that specializes in studying the geochemical reactions that occur at the heart of a planet under heat. and intense pressure.
This study suggests that a rocky planet like the Earth is more likely to acquire life-sustaining elements if it forms and develops from giant impacts with planets that contain different building blocks from other regions of the disc of matter surrounding the Sun and at the origin of the formation of the planets.
The details of this work are published in the journal Science Advances.
Last April, an international team of scientists claimed that much of the water on Earth was present before the cataclysmic collision between the two planets. The planet could have been covered with lakes, rivers and oceans much earlier than it had been estimated so far.