This mosaic of Saturn’s moon Mimas revealing its cratered surface area was produced from images taken by NASA’s Cassini spacecraft. Credit: NASA/JPL-Caltech/Space Science Institute
A brand-new chronology for the moons of Saturn has actually been established by Planetary Science Institute Associate Research Scientist Samuel W. Bell.
“Most research studies dating surface areas on the Moon or Mars count on counting the number of effect craters have actually formed and understanding the cratering rate, however on the moons of Saturn, we do not understand the cratering rate,” stated Bell, author of “Relative Crater Scaling Between the Major Moons of Saturn: Implications for Planetocentric Cratering and the Surface Age of Titan” appearing in the Journal of Geophysical Research: Planets. “Previous chronologies of the Saturn system have assumed that the craters on the moons of Saturn virtually all came from objects orbiting the Sun.”
“If the impacts came solely from Sun-orbiting objects, the relative cratering rate would be much, much higher the closer the moons are to Saturn. However, the crater densities of the oldest surfaces of Mimas, Tethys, Dione, Rhea, and Iapetus are all relatively similar,” Bell stated. “It would be excessive of a coincidence for the ages of the earliest surface areas on each moon to differ by the specific quantities needed to produce broadly comparable crater densities. As an outcome, it appears much likelier that the impactors really originate from things orbiting Saturn itself, moonlets that would be too little to find with existing innovation.
“There are many important implications of this new chronology,” Bell stated. “For circumstances, under the presumption that all the impactors orbit the Sun, the possibility that any of the moons are more youthful than 4 billion years of ages is eliminated. However, with impactors orbiting Saturn itself, the moons might be more youthful, as has actually been recommended from astrometric observations of tidal orbital development.
“The assumption of impactors orbiting the Sun results in the conclusion that the surface of Titan is probably at least 4 billion years old, even though Titan shows clear evidence of active weathering,” Bell stated. “With the brand-new chronology, Titan might be rather young, which is far more constant with observations of lakes, riverbeds, dunes, and mountains.
“With the new chronology, we can much more accurately quantify what we do and don’t know about the ages of the moons and the features on them,” Bell stated. “The grand scale history of the Saturn system still hides many mysteries, but it is beginning to come into focus.”
Reference: “Relative Crater Scaling Between the Major Moons of Saturn: Implications for Planetocentric Cratering and the Surface Age of Titan” by Samuel W. Bell, 26 May 2020, Journal of Geophysical Research: Planets.
DOI: 10.1029/2020JE006392
Bell’s research study was done while he was operating at Brown University’s Center for Computation and Visualization and the Planetary Science Institute.
