According to a groundbreaking new study, life as we know it was the result of a massive collision between Earth and an ancient planet the size of Mars billions of years ago.
The impact between the astronomical body and Earth likely brought various chemical compounds which previously didn’t exist here, according to the study from Science Advances. These volatile elements include sulfur, carbon, and nitrogen – the building blocks of all life and whose timely arrival on Earth was key to our lonely planet’s status as the only one in the universe capable of sustaining life.
According to the research, 4.4 billion years ago Earth was barely in its infancy, in planetary terms, before the Mars-sized astronomical body referred to as Theia violently clashed into it and seeded the planet with these elements.
Scientists had long developed theories that the wayward planetary embryo had crashed into our planet, but the new research spearheaded by planetary scientist Damanveer Grewal relied on high-pressure laboratory experiments and billions of advanced simulations of various paths of the planet’s evolution, putting to the test the idea that our planet was irreversibly altered by the impact in such away that Earth became capable of bringing about life.
A side-effect of this impact was the formation of the Earth’s first satellite, the Moon, which was formed from the debris of the impact – a theory known as the “Giant Impact Hypothesis,” which scientists had previously arrived at.
In a statement, the study’s co-author Rajdeep Dasgupta explained:
“From the study of primitive meteorites, scientists have long known that Earth and other rocky planets in the inner solar system are volatile-depleted … But the timing and mechanism of volatile delivery has been hotly debated. Ours is the first scenario that can explain the timing and delivery in a way that is consistent with all of the geochemical evidence.”
The investigator, who runs a laboratory at Rice University that simulates the intense conditions at the core of planets, added that arriving at a better understanding of the origins of life on Earth has implications that are much farther reaching, and extend beyond the solar system itself.
“This study suggests that a rocky, Earth-like planet gets more chances to acquire life-essential elements if it forms and grows from giant impacts with planets that have sampled different building blocks, perhaps from different parts of a protoplanetary disk,” Dasgupta noted.
Dasgupta added that the formation of a planet is not as the essential elements that later arrive:
“(This study) shows that life-essential volatiles can arrive at the surface layers of a planet, even if they were produced on planetary bodies that underwent core formation under very different conditions.”