The Age of Saturn’s Rings Constrained by the Meteoroid Flux Into the System Conference Proceeding uri icon



  • <p>The origin of Saturn’s ring is still not known. There is an ongoing argument whether Saturn’s ring have been formed shortly after Saturn together with its satellites or they may actually be a recent phenomenon in the solar system. This possibility of young rings has been vigorously debated for nearly 40 years, since the Voyager flybys of Saturn. Over the years, the most powerful support for this hypothesis has turned out to be the puzzle of the rings’ nearly pure water ice composition – unique in the family of planetary rings – in spite of the constant hail of rocky-carbon meteoroids from outside the Saturn system. However, three major uncertainties have left the ‘young-ring’ hypothesis unproven. Two of these have already been resolved by the Cassini mission: the amount of non-icy material currently in the rings, and the total ring mass. The third main constraint is the mass flux of non-icy meteoroids falling onto the rings. <br />Here we report on the measurement of the meteoroid mass flux into the Saturnian system obtained by the charge-sensitive entrance grid system (QP) of the Cosmic Dust Analyser (CDA) on the Cassini spacecraft. The determination mass flux of non-icy material coming into the Saturn system completes the trifecta of constraints that are required to strongly support a youthful ring system. We analyzed the full CDA data set acquired after Cassini’s arrival at Saturn in 2004. The CDA detections determine the incident particle orbits, and they come (surprisingly) not from comets as expected, but mostly from Kuiper Belt Objects (with at least one other population also apparent). This means that most of the particles have low speeds relative to Saturn and are strongly focused gravitationally, such that the flux at the rings is even larger than previously estimated. We have also found that the flux has a statistically significant upper size cutoff, meaning that our detection is robust to Cassini’s finite observation time. </p>

publication date

  • February 26, 2023

has restriction

  • closed

Date in CU Experts

  • February 2, 2018 11:50 AM

Full Author List

  • Kempf S; Altobelli N; J├╝rgen S; Cuzzi J; Estrada P; Srama R

author count

  • 6

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