Earth may have lost between 10 and 60 percent of its atmosphere in the collision thought to have formed the Moon.
New research from Durham University in the UK shows how the magnitude of the atmospheric leak depends on the type of gigantic impact with the Earth.
The researchers ran more than 300 supercomputer simulations to study the consequences several massive collisions have on rocky planets with thin atmospheres.
Their findings have led to the development of a new way to predict atmospheric loss from any collision over a wide range of rocky planet impacts that could be used by scientists studying the origins of the Moon or other giant impacts.
They also found that slow giant impacts between young planets and massive objects could add a significant atmosphere to a planet if the impactor also has a lot of atmosphere.
The results are published in Letters from astrophysics journals.
The Moon is believed to have formed about 4.5 billion years ago following a collision between early Earth and a giant impactor perhaps the size of Mars.
The lead author of the research, Dr Jacob Kegerreis, of the Institute of Computational Cosmology, Durham University, said: “The puzzle of how the Moon formed and the other consequences of a giant collision with the early Earth is something that scientists are working hard to unravel.
“We ran hundreds of different scenarios for many different colliding planets, showing the different impacts and effects on a planet’s atmosphere depending on a variety of factors such as the angle, speed of impact or size of the planets.
“While these computer simulations do not directly tell us how the Moon was born, the effects on Earth’s atmosphere could be used to narrow down the different ways it might have formed and bring us closer to understanding the origin of our closest celestial. neighbour.”
Earlier this year, an initial study from Durham University reported that giant impacts dominating the later stages of planet formation can have a wide range of consequences for young planets and their atmospheres.
The study looked at ways in which subtle atmospheres could be removed from impacting objects at different angles and speeds.
The researchers’ latest paper examines the effects on a much wider variety of impacts by adjusting the size, mass, velocity and angle of the impacting object. They also changed the density of the impactor and whether it was made of iron, rock, or both.
The simulations revealed the different results when one or more of these variables are changed, leading to atmospheric loss or gain, or sometimes to complete obliteration of the affected planet.
The research team also included scientists from BAERI / NASA Ames Research Center and the University of Washington, USA, and the University of Glasgow, UK.
Co-author Dr. Luis Teodoro, of the School of Physics and Astronomy, University of Glasgow, and BAERI / NASA Ames Research Center, said: “This important suite of planetary simulations also sheds light on the role of impacts in the evolution of the Earth as exoplanets. ”
The supercomputer reveals the atmospheric impact of gigantic planetary collisions
Atmospheric Erosion by Giant Impacts on Terrestrial Planets: A Law of Scale for Any Speed, Angle, Mass, and Density, Kegerreis J, et al, will be published in The Letters from astrophysics journals, DOI: 10.3847 / 2041-8213 / abb5fb
Planet collision simulations provide clues to atmospheric loss from the moon’s origin (2020, September 29)
recovered on September 30, 2020
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