About 150 million years ago, one of the more than 80 moons orbiting Saturn became too unstable and came dangerously close to the planet before colliding with it, causing the current 26.7 degree tilt that it presents with respect to the Sun and gave rise to the characteristic rings that give the star a unique appearance.
This is the main conclusion of a modeling study carried out by astronomers of the Massachusetts Institute of Technology (MIT) and that, after being published this Thursday in the magazine Sciencehas aroused the consensus of a large part of the scientific community regarding several of the great mysteries that surround this celestial body.
Using data from the Cassini mission, which between 2004 and 2017 analyzed the composition of the second largest planet in the Solar System and many of its 83 moons, the team carried out various numerical simulations with which they have ended up reaching this assumption. Although it will be necessary to carry out more investigations to corroborate it, the finding supposes a solid starting point to explain the current appearance of Saturn.
According to the simulations carried out, the rings did not form until millions of years after the impact as a consequence of the disintegration of the moon into innumerable ice fragments. Until now, all that was known was that the rings were much later than the birth of the planet, with an age of approximately 100 million years.
The authors have baptized the exploded moon with the name of Chrysalissince, according to Jack WisdomMIT professor of planetary sciences and lead author of the study, “Like a butterfly’s chrysalis, this satellite was dormant for a long time and then suddenly became active,” eventually giving rise to the rings.
Resonance with Neptune
The new hypothesis about the inclination of Saturn represents a new twist with respect to the previous one, formulated in the early 2000s and according to which the axis was a consequence of the planet being trapped by a resonance, or gravitational partnership, with Neptune.
But as MIT now posits, it would really be the titan migrationthe largest satellite of Saturn and moving away from the planet at a rate of about 11 centimeters per year, and its gravitational attraction which would maintain Saturn’s inclination and resonance with its neighboring planet.
“It’s a pretty good story, but like any outcome, it’s going to have to be vetted by others,” Wisdom says.