The histories of planets across our solar system and beyond are filled with collisions and transformations. New research is helping scientists understand how colossal impacts, like the one with Earth thought to have formed the Moon, are impacting the atmospheres of rocky planets.
In the animation above, a Mars-like mass grazes an Earth-like mass, replicating the traditional theory for the impact that formed the Moon. Some atmosphere is lost, accompanied by a shockwave. This is one of more than 300 simulations that scientists at Durham University in the United Kingdom, alongside researchers at NASA’s Ames Research Center in California’s Silicon Valley, ran to develop a way to predict how much atmosphere is lost from a wide range of collisions between rocky objects, presented in a new study.
Results from these simulations show that, depending on the scenario, 10% to 60% of Earth’s atmosphere could have been lost in the collision that created the Moon, helping scientists narrow down theories about its creation. By looking at a wide range of factors, such as size, speed, composition, and angles of the objects colliding, the researchers were able to explore a variety of scenarios, showing that collisions with young planets can even add atmosphere to a planet if the impactor has some to give.
This research was funded by NASA, the Science and Technology Facilities Council in the U.K., and The Royal Society in the U.K. Simulations were carried out using the COSmology MAchine, or COSMA, supercomputer, part of the Distributed Research utilising Advanced Computing, or DiRAC, High-Performance Computing facility based in Durham, U.K., using the SPH With Interdependent Fine-grained Tasking, or SWIFT, open-source simulation code.
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