Life on Earth
Has the violent cosmic collision that created the moon made life on Earth possible? A new study suggests this.
There are a number of theories about the origin of life on earth, many of which seek to explain how our planet has received the ingredients for life: elements such as carbon and nitrogen.
So far, scientists have done this suggesting that meteorites provided the earth with life-giving elements. While the isotopic signatures of these elements on Earth are consistent with these objects, the ratio of carbon to nitrogen is not quite correct. While the meteorites that were thought to have delivered vital elements for the earth (known as carbonaceous chondrites) contain 20 parts of carbon for each part of nitrogen, this ratio on Earth is about 40-1
Instead, these crucial elements could have been delivered in a stunning collision, says a group of petrologists at Rice University. Scientists know that the Moon was created a long time ago by a collision between the Proto-Earth and a Mars-sized object – the same impactor could have given us the elements for the excitement of life.
The research team created a simulation of the event based on a series of experiments that tested the behavior of carbon, nitrogen and sulfur during the nucleation process on a rocky planet. The team then simulated the high pressures and temperatures during nucleation and estimated how much carbon or nitrogen could be in a Mars-rich planet with sulfur-containing nuclei. They ended with a geochemical simulation that accurately modeled observations of carbon, nitrogen, and sulfur on Earth.
A Probable Scenario
With their simulation, the team took place along with the known proportions and concentrations of elements on Earth. The most probable explanation for a meteor shower with crucial elements is that they all came at the same time.
"Our simulation results suggest that the most likely scenario is the formation of carbon, nitrogen and sulfur on the siliceous part of the earth. There these elements are from a Mars-sized planet (8-10 mass% of today's earth) with the Proto-Earth merged, "says Rajdeep Dasgupta, co-author of the newspaper in an e-mail. Besides, such a planet would probably have had a sulfur-rich core.
The work does not solve the question of how life originated on Earth, but it begins to answer the question of how the ingredients for life could have come here. "There are many unanswered questions about how life really came about. However, our study provides a mechanism to preserve the raw materials for the recipe, "said Dasgupta.
This paper is published in the journal Science Advances