New research from Durham University, UK, shows how the extent of atmospheric loss depends on the nature of the huge impact with the earth.
The researchers performed more than 300 supercomputer simulations to study the consequences of various large collisions on rocky planets with thin atmospheres.
Their results have led to the development of a new method to predict atmospheric loss from collisions over a variety of impacts on rocky planets that could be used by scientists studying the origins of the moon or other giant influences.
They also found that slow giant impacts between young planets and massive objects can give a planet a significant atmosphere if the impactor also has a lot of atmosphere.
The results will be published in the Astrophysical diary letters.
Cross-sectional animation of the early stages of a 3D simulation of a frontal, slow giant impact using 30 to 100 million particles colored by its material or its internal energy related to its temperature. Photo credit: Jacob Kegerreis, Durham University
The moon is believed to have formed about 4.5 billion years ago after a collision between early Earth and a giant impactor, possibly the size of Mars.
Lead research author Dr. Jacob Kegerreis of the Department of Computational Cosmology at Durham University said: “The mystery of how the moon was formed and the other consequences of a huge collision with early Earth is something scientists are working hard to solve.
“We ran hundreds of different scenarios for many different colliding planets, showing the different effects and effects on the atmosphere of a planet depending on a number of factors such as angle, impact speed or size of the planets.
“While these computer simulations don’t tell us directly how the moon was formed, the effects on Earth’s atmosphere could be used to narrow down the different ways it was formed and bring us closer to understanding the origin of our closest neighbor.”
Earlier this year, an initial study from Durham University reported that giant influences dominating the late stages of planet formation can have a variety of consequences on young planets and their atmosphere.
Cross-sectional animation of the early stages of a 3D simulation of a grazing, rapid giant impact with 30 to 100 million particles, colored by its material or its internal energy, based on its temperature. Photo credit: Jacob Kegerreis, Durham University
This study investigated how thin atmospheres can be removed by objects striking at different angles and speeds.
The researchers’ latest paper looks at the effects of a much wider variety of impacts, taking into account the size, mass, speed and angle of the impacting object. They also changed the density of the impactor and whether it was made of iron, stone, or both.
The simulations showed the different results when one or more of these variables were changed, resulting in atmospheric loss or gain, or sometimes the complete obliteration of the affected planet.
Reference: “Atmospheric erosion due to giant impacts on terrestrial planets: A scaling law for every speed, every angle, every mass and every density” by JA Kegerreis, VR Eke, DC Catling, RJ Massey, LFA Teodoro and KJ Zahnle, Astrophysical diary letters.
DOI: 10.3847 / 2041-8213 / abb5fb
The research team also included scientists from BAERI /NASA Ames Research Center and the University of Washington, USA and the University of Glasgow, UK.
The co-author Dr. Luis Teodoro of the Faculty of Physics and Astronomy at the University of Glasgow and the BAERI / NASA Ames Research Center said, “This large series of planetary simulations also sheds light on the role of the effects on the evolution of Earth-like exoplanets. ”
The high-resolution simulations were carried out with the open source simulation code SWIFT. They were conducted on the COSMA supercomputer, which is part of the DiRAC high-performance computing facility in Durham, funded by the Science and Technology Facilities Council (STFC).
The research was funded by the STFC, NASA, and the Royal Society.