Giant impacts have a wide range of consequences for young planets and their atmospheres, according to research led by our scientists.
These huge collisions dominate the late stages of planet formation.
Using 3D supercomputer simulations the researchers have found a way of revealing how much atmosphere is lost during these events.
Their simulations show how Earth-like planets with thin atmospheres might have evolved in an early solar system depending on how they were impacted by other objects.
They ran more than 100 detailed simulations of different giant impacts, 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 4.5 billion years ago – 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 research tells us more about 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.
This will help us to understand both the Earth’s history as a habitable planet and the evolution of exoplanets around other stars.
The researchers are carrying out hundreds more simulations to test the effects that the different masses and compositions of colliding objects might have.