Saturn's Rings May be No More Than 400 Million Years Old
janrinok writes:
The earliest trilobites may have evolved before Saturn donned its icy hoops
Saturn's rings might have formed while trilobites scuttled about on Earth. Space dust has been accumulating on the icy halos for no more than 400 million years, researchers report in the May 12 Science Advances.
The 4.5-billion-year-old planet appears to have acquired its iconic ornamentation relatively recently, says physicist Sascha Kempf of the University of Colorado Boulder. "We're quite lucky to see a ring in the first place."
The rings of Saturn are made of countless icy particles, which become covered with dust as tiny meteoroids strike them. These dustings darken the rings' complexion, like mud sullies snow on roads in winter.
[...] The age of the rings has been debated for decades [...]. Even after the new study, there's still disagreement.
If the rings are somehow losing dust over time, they could be ancient, says planetary scientist Aurelien Crida of Universite Cote d'Azur in Nice, France, who was not involved in the study. "Possibly as old as Saturn."
It seems clear that the rings have been exposed to micrometeoroid impacts for at least a hundred million years, Crida says. But simulations of the rings' formation from the gravitational shredding of an early moon suggest their size is consistent with an age of billions of years, he says. And researchers have reported silicate grains falling from the rings into Saturn's atmosphere (SN: 10/4/18). Some unidentified process might be cleaning the rings of the micrometeoroid dust, making them appear younger than they are, Crida says.
[...] Experiments that smash micrometeoroids into ice particles could help resolve the discrepancy, Crida says. For now, the debate over the age of the rings lives on.
Journal Reference:
S. Kempf et al. Micrometeoroid infall onto Saturn's rings constrains their age to no more than a few hundred million years. Science Advances. Vol. 9, May 12, 2023. doi: 10.1126/sciadv.adf8537
Read more of this story at SoylentNews.