NASA notes that Earth’s moon didn’t take hundreds of years to form. Try hours.

When the universe seemed like one vast, lonely place, people have found solace in Earth’s steadfast companion—the moon—always marching through space with this planet on an odyssey around the sun.

But at one time, about 4.5 billion years ago, the moon wasn’t there. And even though it’s the cosmic beast and Earth’s closest neighbor, scientists are still not sure how it got there.

Since the 1980s, the leading theory has been that a massive planet, perhaps the size of Mars, crashed into Earth billions of years ago, spurting an entire world’s worth of gas, magma and metals that encroached the moon over tens to hundreds years formed. A study published on Tuesday in The Letters of the Astrophysical Journal proposes a bold new idea: The moon could have formed in a rapid exchange, blowing much of baby Earth and its impactor material into wide orbit — in a matter of hours.

If true, the research, which has focused on hundreds of extremely high-resolution computer simulations of one such collision, could help solve a long-standing headache for scientists about why the moon’s crust appears so damn similar to Earth’s. It also provides possible answers as to why the moon is tilted and has a thin outer layer. Cosmologists yearn to piece together what happened to not only flesh out the Moon’s formation story, but also explain a pivotal moment in Earth’s evolution.

NASA and collaborators put together a quick two-minute animation attempting to show how the new model would unfold. A planet that scientists over the decades have dubbed “Theia” slams into a primitive version of Earth like a ball of paint, shedding a concoction of planetary guts. However, instead of forming a thin disc of debris, it splits into another chunk, jo-joing between the material. Earth’s gravity keeps throwing the smaller body, but it survives. Cut the umbilical cord.

This dance of destruction is contrasted by a musical score of lullaby-like plinking on a marimba.

“I always thought it would be great to actually have sort of real sound effects that included explosions,” says Jacob Kegerreis, the paper’s lead author and a postdoctoral fellow at the NASA Ames Research Center in California. joked with Mashable.

“I always thought it would be great to actually have sort of real sound effects that included explosions.”

For years, scientists have run lower-resolution computer models of the giant impact without the two bodies splintering apart. In this case, NASA partnered with Durham University’s Institute of Computational Cosmology in England to run simulations at up to 1,000 times the resolution of the standard, testing different impact angles, velocities, planetary rotations and sizes, and observed.

What emerged from the increased computing power were behaviors not observed in previous research. And when there was some previous, sparse evidence of a crash that could split into two blobs, the researchers cast doubt on the result as a numerical problem with their model, Kegerreis said.

This new model uses hundreds of millions of tiny particles to represent the planetary bits. In theory, if they can describe how these materials interact through gravity, pressure and heat, the system should behave accurately, he said.

Kegerreis explains the concept with an analogy of dropping a ball to break it.

“If you build this ball out of little Lego bricks and you only have 50 of them, it could split perfectly in an unrealistic way,” he said. “But if you have thousands or millions of it, you might find out how it’s actually fragmented in a more realistic way, and it’s the same kind of idea.”

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About a decade ago, scientists scrutinized the giant impact theory because of a chemical controversy. Researchers analyzing Apollo lunar samples in the 21st century had found that the lunar rocks had the same chemical signature as Earth’s mantle, but that Martian meteorites and objects from other parts of the solar system had different compositions. That would suggest that off-earth sources should look quite different.

Then how could the moon be a mix of Earth and a mysterious planet with no trace of otherworldly chemical signatures, you wondered?

Scientists continue to debate the problem. Meanwhile, the new NASA computer simulation has the advantage of resulting in a moon composed mostly of Earth material.

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Understanding the moon’s composition isn’t easy, in part because scientists base their knowledge on a small collection of rocks from a tiny area near the moon’s equator. NASA scientists are excited for the Artemis lunar landing missions, which will explore an entirely different region to gather more data, including samples mined deeper in the moon’s interior.

What excites cosmologists like Kegerreis is how the study opens up new ways to study how the moon formed.

“On the one hand, [these events] are absolutely very violent and somewhat disruptive, but they are also very constructive,” he said, adding that before Theia, there were likely other important collisions that played a key role in bringing Earth to its current habitable state.”