Supercomputer simulations could reveal mystery of Moon formation

Astronomers have taken a step forward to understand how the Moon could have formed as a result of a giant collision between the early Earth and another massive object 4.5 billion years ago.

Scientists led by the University of Durham, UK, ran supercomputer simulations on the DiRAC high-performance computing facility to send a Mars-sized planet – called Theia – to crash into early Earth .

Their simulations produced an orbiting body that could potentially evolve into a moon-like object.

While the researchers are careful to say that this is not definitive proof of the Moon’s origin, they add that it could be a promising step in understanding how our closest neighbor might have formed.

The results are published in the journal Monthly notices from the Royal Astronomical Society.

The Moon is believed to have formed during a collision between early Earth and Theia, which scientists believe could have been an ancient planet in our solar system, the size of Mars.

The researchers ran simulations to track material from early Earth and Theia for four days after their collision, then ran further simulations after spinning Theia like a billiard ball.

The simulated collision with the early Earth produced different results depending on the size and direction of Theia’s initial spin.

At one extreme, the collision merged the two objects, while at the other, there was a hit-and-run impact.

Importantly, the simulation where no spin was added to Theia produced a self-gravitating cluster of material with a mass of about 80% of the Moon, while another Moon-like object was created when a small amount of rotation has been added.

The resulting cluster, which settles in an orbit around Earth after impact, would grow by sweeping away the debris disk surrounding our planet.

The simulated tuft also has a small iron core, similar to that of the Moon, with an outer layer of material made up of the early Earth and Theia.

A recent analysis of oxygen isotope ratios in lunar samples collected by the Apollo space missions suggests that a mixture of materials from ancient Earth and the impactor could have formed the moon.

Lead author Sergio Ruiz-Bonilla, a Ph.D. researcher from the Institute for Computational Cosmology at Durham University, said: “By adding different amounts of spin to Theia in the simulations, or not having no rotation at all, this gives you a whole range of different results for what might have happened when early Earth was struck by a massive object all those billions of years ago.

“It’s exciting that some of our simulations produced this orbiting group of material that is relatively not much smaller than the Moon, with an additional disc of material around the Earth after impact that would help the block to grow in mass over time.

“I wouldn’t call it the Moon, but it’s definitely a very interesting place to keep looking.”

The Durham-led research team now plans to run further simulations modifying the mass, velocity and rotational speed of the target and impactor to see what effect this has on the formation of a potential Moon. .

Co-author Dr Vincent Eke, Institute for Computational Cosmology at Durham University, said: “We get a number of different results depending on whether or not we introduce the spin to Theia before it s. ‘crushes on the primitive Earth.

“It is particularly fascinating that when no or very little rotation is added to Theia, the impact with the early Earth leaves a trail of debris behind, which in some cases includes a body large enough to merit being killed. ‘to be called proto-moon.

“There may be a number of possible collisions that have not yet been investigated that could bring us even closer to how the Moon formed in the first place.”