Saturn’s famous rings aren’t the kind of sparkle you get easily — and new theory suggests they formed when one of the gas giant’s moons got close to the massive planet.
This unfortunate satellite may have fallen into the intense gravitational field of its host, which then caused it to separate from each other. Scientists think that the resulting debris may have formed many of the rings we see today. At least that’s what a team of researchers led by Jack Wisdom of the Massachusetts Institute of Technology suggests, who named the lost moon “Chrysalis.”
He says this story also helps explain the unusual tilt of Saturn’s axis and why the rings are thought to be To be more than 100 million years oldwhen Saturn formed itself more than four billion years ago.
“The tilt is too large to be the result of known formation processes in a protoplanetary disk or from subsequent large collisions,” Wisdom He said in a statement. “A variety of explanations were offered, but none were entirely convincing. The remarkable thing is that the previously unexplained young age of the episodes was naturally explained in our scenario.”
An outline of the team theory can be found in the file published a paper In the latest issue of Science magazine.
Searching for the missing moon of Saturn
Saturn orbits the sun tilted 26 degrees to one side, a more dramatic position than Earth’s tilt, which oscillates between 22.1 and 24.5 degrees. The most likely explanation for this has always been that Saturn’s tilt comes from the kind of gravitational dance that the planet shares with Neptune.
But Wisdom and his colleagues, with the help of data from NASA’s Cassini spacecraft, have run some new models that indicate that while Saturn and Neptune once reverberated in the past, something changed about 160 million years ago. This thing removed Saturn from the influence of Neptune.
Among a number of simulations, the one that best fit all the data was a hypothetical one in which Saturn had lost a relatively large moon.
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Today, the giant planetary system hosts 83 moons. Chrysalis would have been the size of Iapetus, which is currently Saturn’s third largest moon. Scientists for the new study hypothesized that between 200 and 100 million years ago, the forgotten moon began to be swept away by the gravitational field of Titan, Saturn’s largest moon. In turn, this could have disrupted Chrysalis’ orbit, sending it on a chaotic path that involved nearly colliding with Iapetus and Titan, and eventually getting too close to Saturn itself.
Such an encounter, say the researchers, could have ripped the Moon into smithereens, as Saturn would likely have used up so much of the remnants, a small part forming what we now know as those wonderful rings. This seems to be the perfect explanation, solving two cosmic mysteries at once, but Wisdom cautions that it remains a theory.
“Like any other result, it has to be vetted by others,” he said, adding that it makes for a great story in the meantime.
“Just like a butterfly cocoon, this satellite had been dormant for a long time and suddenly became active, and the rings appeared.”