A new set of supercomputer simulations has offered an answer to the mystery of the origin of Saturn’s rings, which involves a large-scale collision in the solar system’s recent 4.5 billion year history. According to new research published Astrophysical Journal Saturn’s rings may have formed from the debris of two icy protomoons that collided and broke apart just a few hundred million years ago, according to a study involving NASA and the universities of Durham and Glasgow.

They will most likely be similar in size to Saturn’s two current moons, Dione and Rhea.

Debris that did not enter the rings may also have contributed to the formation of some of Saturn’s modern moons. Most of the existing high-quality measurements of Saturn were made by the Cassini spacecraft. After entering Saturn’s orbit in 2004, it studied the planet and its systems for 13 years.

The Cassini spacecraft obtained accurate data by passing by and even diving into the gap between Saturn’s rings and the planet itself. Cassini found that the rings are composed of nearly pure ice and have accumulated very little dust since their formation; this suggests that they formed in the last few percent of the solar system’s lifespan.

Spurred on by the rings’ extraordinary youth, the research team turned to the COSMA machine, located at Durham University as part of the UK’s DiRAC (Distributed Research Using Advanced Computing).

The team modeled what various collisions between early moons might have looked like. These hydrodynamic simulations were performed at a resolution 100 times higher than previous studies using open-source SWIFT software, providing scientists with the best-ever understanding of the history of the Saturn system.

Associate Professor at Durham University’s Department of Physics/Institute for Computational Cosmology. Vincent Eke said: “We tested the hypothesis regarding the recent formation of Saturn’s rings and found that the impact of icy moons could have sent enough material near Saturn to form the rings we see now.

“This scenario naturally leads to ice-rich rings because when protoplanets collide, the rock in the cores of the colliding bodies is dispersed over a less wide area than the overlying ice.”

Today, Saturn’s rings lie close to the planet in its outermost orbit, called the Roche limit, where the planet’s gravitational pull is strong enough to shatter approaching large masses of rock or ice. Materials orbiting further away can come together to form satellites.

After simulating nearly 200 different collision scenarios, the research team found that a wide range of collision scenarios could distribute the right amount of ice to Saturn’s Roche boundary, where Saturn would settle into rings as icy as today. Alternative explanations could not explain why Saturn’s rings contained almost no rock, as the rest of the system had a mixed composition of ice and rock.

Durham University graduate Dr. currently works as a researcher at NASA’s Ames Research Center in Silicon Valley, California. Jacob Kegerreis said: “There’s a lot we don’t know about the Saturn system, including its moons; it’s suitable for life, so it’s exciting to explore in detail how they might have evolved using large simulations like this.”

from the School of Physics and Astronomy at the University of Glasgow. Louis Teodoro said: “The apparent geological youth of Saturn’s rings has been a mystery since the Voyager probes sent back the first images of the planet. This collaboration allowed us to explore the possible conditions of their creation with exciting results.”