Earth may have lost up to 60 per cent of its atmosphere in the collision that is thought to have formed the Moon
- Researchers carried out hundreds of collision simulations on a supercomputer
- They looked at different impact angles, planet densities and even atmospheres
- Earth could have lost 10-60 per cent of its atmosphere in an early collision
- The new models could be used to better understand how the Moon first formed
The Earth may have lost as much as 60 per cent of its atmosphere in a collision with another young planet that created the Moon, a new study revealed.
New research led by Durham University involved more than 300 supercomputer simulations designed to show the consequence of a huge collision on the planet.
Their findings have led to the development of a new way to predict the atmospheric loss from any collision across a wide range of rocky planet impacts.
These could be used by scientists investigating the Moon’s origins or other giant impacts both in our own solar system and on rocky exoplanets light years away.
New research led by Durham University involved more than 300 supercomputer simulations designed to show the consequence of a huge collision on the planet. This is a cross section of a 3D simulation involving two young planets colliding into one another
Their findings have led to the development of a new way to predict the atmospheric loss from any collision across a wide range of rocky planet impacts. The simulations incorporate different materials, density and impact angles
The Moon is believed to have formed about 4.5 billion years ago following a collision between the early Earth and a giant impactor possibly the size of Mars.
Lead author Dr Jacob Kegerreis, in the Institute for Computational Cosmology, Durham University, said scientists are working hard to unravel the mystery.
‘We ran hundreds of different scenarios for many different colliding planets, showing the varying impacts and effects on a planet’s atmosphere depending upon a number of factors such as the angle, speed of impact or the sizes of the planets.’
The simulations can’t directly say how the Moon came to be, but they could show the effects a giant collision had on the Earth’s atmosphere.
This ‘could be used to narrow down the different ways it might have been formed and lead us closer to understanding the origin of our nearest celestial neighbour.’
Earlier this year, an initial study by Durham University reported that giant impacts which dominate the late stages of planet formation can have a wide range of consequences for young planets and their atmospheres.
That study examined the ways that a planet’s atmospheres could be changed by objects impacting at different angles, mass, size and speeds.
Simulations revealed Earth could have lost anywhere between 10-60 per cent of its atmosphere in the collision where the Moon came into existence.
The researchers say the findings also provide a new way to predict the atmospheric loss from other rocky planets that have been involved in collision.
It can go the other way, authors found a slow giant impact between two objects with a lot of atmosphere could add significant atmosphere to both worlds.
This latest paper looks at the effects across a much wider variety of impacts adjusting for size, mass, speed and angle of the impacting object.
The simulations can’t directly say how the Moon came to be, but they could show the effects a giant collision had on the Earth’s atmosphere
They also changed the density of the impactor and whether it was made of iron, rock or both as part of the new study.
The simulations revealed the different outcomes when one or more of these variables are changed, leading to atmospheric loss or gain or sometimes the complete obliteration of the impacted planet.
Co-author Dr Luis Teodoro, in the School of Physics and Astronomy, University of Glasgow, said: ‘This major suite of planetary simulations also sheds light on the role of impacts in the evolution of Earth-like exoplanets.’
The high-resolution simulations were run using the SWIFT open-source simulation code. They were carried out on the COSMA supercomputer, part of the DiRAC High-Performance Computing facility in Durham.
The findings are published in The Astrophysical Journal Letters.
SCIENTISTS DON’T AGREE ON HOW THE MOON FORMED BUT MANY BELIEVE IT WAS THE RESULT OF AN IMPACT BETWEEN EARTH AND ANOTHER PLANET
Many researchers believe the moon formed after Earth was hit by a planet the size of Mars billions of years ago.
This is called the giant impact hypothesis.
The theory suggests the moon is made up of debris left over following a collision between our planet and a body around 4.5 billion years ago.
The colliding body is sometimes called Theia, after the mythical Greek Titan who was the mother of Selene, the goddess of the moon.
Many researchers believe the moon formed after Earth was hit by a planet the size of Mars billions of years ago. This is called the giant impact hypothesis
But one mystery has persisted, revealed by rocks the Apollo astronauts brought back from the moon: Why are the moon and Earth so similar in their composition?
Several different theories have emerged over the years to explain the similar fingerprints of Earth and the moon.
Perhaps the impact created a huge cloud of debris that mixed thoroughly with the Earth and then later condensed to form the moon.
Or Theia could have, coincidentally, been chemically similar to young Earth.
A third possibility is that the moon formed from Earthen materials, rather than from Theia, although this would have been a very unusual type of impact.