Scientists Say Life Possible Because of a Big Bang: a Planet Colliding With Earth
Scientists at Rice University are claiming that the essential elements – including nitrogen and carbon – that make life on Earth possible likely arrived during the same impact that created our moon. A Rice University press release stated that their findings, published in Science Advances, were based on evidence gathered from experiments that study geochemical reactions taking place under conditions of high heat and pressure, like those in Earth's core.
The experiments were conducted in study co-author Rajdeep Dasgupta's laboratory and led by graduate student Damanveer Grewal who sought to test a theory that some of Earth's elements came as a result of collision with a planet with a sulfur-rich core. The sulfur component is essential to the theory, the press release notes, because of the lack of sulfur, nitrogen, and carbon in Earth's core, despite their abundance elsewhere. "The core doesn't interact with the rest of Earth, but everything above it, the mantle, the crust, the hydrosphere and the atmosphere, are all connected," Grewal said. "Material cycles between them."
The researchers state that a collision with a "Mars-sized" planet that formed the moon 4.4 billion years ago is responsible for Earth's life-giving elements. "Ours is the first scenario that can explain the timing and delivery in a way that is consistent with all of the geochemical evidence," Dasgupta said, adding that "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."
Perhaps we might see progress in a search for extraterrestrial life by looking more closely at planets that have undergone significant bombardment.