The source of Saturn's G ring
Matthew M Hedman1, Joseph A Burns, Matthew S Tiscareno
1Department of Astronomy, Cornell University, Ithaca, NY 14853, USA. mmhedman@astro.cornell.edu
Science (New York, N.Y.)
|August 4, 2007
Summary
Saturn's G ring likely originates from a debris arc trapped in resonance with the moon Mimas. This arc contains both dust and larger bodies, suggesting a unique origin for the ring system.
Area of Science:
- Planetary Science
- Astronomy
- Ring Dynamics
Background:
- The origin of Saturn's narrow G ring has remained an unresolved question in planetary science.
- Previous observations primarily identified small dust grains within the G ring.
Purpose of the Study:
- To investigate the source and composition of Saturn's G ring.
- To explain the presence of a bright, localized arc within the G ring.
Main Methods:
- Analysis of data from the Cassini spacecraft, including camera observations and energetic particle flux measurements.
- Orbital dynamics calculations to identify resonant interactions between ring material and Saturnian moons.
Main Results:
- A bright arc was identified within the G ring, located approximately 167,496 km from Saturn's center.
- This arc is trapped in a 7:6 corotation eccentricity resonance with the moon Mimas.
- Observations suggest the arc comprises both small dust particles and larger, centimeter- to meter-sized bodies, implying a substantial total mass.
Conclusions:
- The G ring's origin is likely linked to this debris arc, potentially formed from the erosion of larger bodies.
- Collisions involving these larger bodies may continuously replenish the G ring with dust.
- The resonance with Mimas is crucial for maintaining the stability and structure of this arc and, consequently, the G ring.
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