A long-lost moon gave Saturn its signature rings


The planet’s rings could be from an old lost moon, according to space scientists from the Massachusetts Institute of Technology and the University of California, Berkeley.

Today, Saturn has 82 moons, according to NASA. The research team proposed that the ringed planet may have another one that orbited the planet for billions of years.

But about 160 million years ago, this moon became unstable and got too close to Saturn The moon was shattered in what researchers described as a “grazing encounter.”

While the gas giant probably engulfed 99% of the moon, the rest remained suspended in orbit, eventually breaking up into tiny chunks of ice that formed the planet’s rings, scientists have suggested.

Previous studies estimated that Saturn’s rings were 100 million years old, much younger than the planet itself. although their age is a matter of intense debate. This latest study provides a possible explanation for their subsequent origin.

“Many explanations have been offered, but none of them are entirely convincing. The nice thing is that the previously unexplained young age of the rings appears naturally in our scenario,” said study author Jack Wisdom, a professor of planetary science at Massachusetts Institute of Technology. Institute of Technology, in a news release.

The new study, published Thursday in the journal Science, is based on modeling based on measurements made in 2017 at the end of NASA’s Cassini mission, which spent 13 years exploring Saturn and its moons.

Saturn’s unusual tilt

The research also sheds light on two other surprising features of Saturn.

Astronomers previously suspected that the planet’s 26.7-degree tilt came from gravitational interactions with its neighbor Neptune, but the study suggests that the lost moon theory may offer a better explanation. The two planets may once have been in sync, and the loss of a moon may have been enough to pull Saturn away from Neptune’s pull and leave it with its current declination.

“The inclination is too large to be the result of known formation processes in a protoplanetary disk or major later collisions,” Wisdom said.

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Scientists believe that the same event may be the start of Saturn’s moon Titan — the second largest moon in the solar system and larger than the planet Mercury — in its strange orbit. The moon is rapidly migrating away from Saturn at about 11 centimeters (4.3 inches) a year, the study said.

Researchers named the lost moon Chrysalis because of the way it transformed the planet.

“Like the chrysalis of a butterfly, this satellite was dormant for a long time and suddenly became active, and the rings formed,” Wisdom said.

He added that the research told a “pretty good story” but that other astronomers should try and study it.