The giant impacts that dominate late stages of planet formation have a wide range of consequences for young planets and their atmospheres, according to new research.
Research led by Durham University and involving the University of Glasgow, both UK, has developed a way of revealing the scale of atmosphere loss during planetary collisions based on 3-D supercomputer simulations.
The simulations show how Earth-like planets with thin atmospheres might have evolved in an early solar system depending on how they are impacted by other objects.
Using the COSMA supercomputer, part of the DiRAC High-Performance Computing facility in Durham, funded by the Science and Technology Facilities Council (STFC), the researchers ran more than 100 detailed simulations of different giant impacts on Earth-like planets, altering the speed and angle of the impact on each occasion.
They found that grazing impacts—like the one thought to have formed our Moon—led to much less atmospheric loss than a direct hit.
Head on collisions and higher speeds led to much greater erosion, sometimes obliterating the atmosphere completely along with some of the mantle, the layer that sits under a planet's crust.
The findings provide greater insight into what happens during these giant impacts, which scientists know are common and important events in the evolution of planets both in our solar system and beyond.