New version page

UI ECE 591 - Wavelike Structure in Saturn’s Rings

Documents in this Course


34 pages



11 pages

Load more
Upgrade to remove ads
Upgrade to remove ads
Unformatted text preview:

Wavelike Structure in Saturn’s RingsOverviewHistorySlide 4Saturn’s Ring SystemSlide 6SatellitesWavelike StructureVoyager Occultation ExperimentsSlide 10Spiral Density WavesSlide 12Slide 13Feature SearchPossible Density WavePrometheus 5:4 Surface Mass Density ResultsMimas 4:1The GapWakesPanPossible Wakes near 119950 kmPossible Wake?Wake FitsIrregular StructureSources of Irregular StructureInner B Ring – Large StructureInner B Ring Finer Irregular StructureC Ring 1000 km wavesRinglets in the C RingSlide 30ObservationsAcknowledgementsWavelike Structure in Wavelike Structure in Saturn’s RingsSaturn’s RingsBenjamin PollardBenjamin Pollard2/09/062/09/06OverviewOverviewRing SystemRing SystemHistory History DescriptionDescriptionSatellitesSatellitesTypes of StructureTypes of StructureVoyager Occultation ExperimentsVoyager Occultation ExperimentsData and Analysis MethodData and Analysis MethodObserved Ring StructureObserved Ring StructureDensity wavesDensity wavesWakesWakesIrregular StructureIrregular StructureHistoryHistory• Galileo – 1610• Christian Huygens - 1655• Jean Chapelain – 1660• Jean-Dominique Cassini – 1660’s• James Clerk Maxwell - 1857Ring Particle ModelsSaturn’s Ring SystemSaturn’s Ring SystemApproximately 340,000 km from edge to edgeApproximately 340,000 km from edge to edge100 meters thick100 meters thick7 major rings7 major ringsLess than 10 million years old?Less than 10 million years old?Saturn’s Ring System Saturn’s Ring System CCAABBEncke GapCassini DivisionCassini ISSSatellitesSatellites39 known satellites39 known satellitesDiameter of 7 km to 5150 Diameter of 7 km to 5150 kmkmResponsible for some Responsible for some ring structurering structureProduce waves in the Produce waves in the ringsringsSpiral density wavesSpiral density wavesBending wavesBending wavesWakesWakesShepherd F ringShepherd F ringGaps and RingletsGaps and RingletsWavelike StructureWavelike StructureDensity WavesDensity WavesBending WavesBending WavesWakesWakesIrregular StructureIrregular StructureCassini UVISCassini ISSCassini ISSVoyager Occultation ExperimentsVoyager Occultation ExperimentsVoyager 1Voyager 1November 13, 1980November 13, 1980Radio Science Experiment (RSS)Radio Science Experiment (RSS)Spacecraft occulted from earthSpacecraft occulted from earthMaximum resolution of 0.2 km Maximum resolution of 0.2 km (RSS)(RSS)Voyager 2 Voyager 2 August 25, 1981August 25, 1981Photopolarimeter Experiment Photopolarimeter Experiment (PPS)(PPS)Ultraviolet Spectrometer Ultraviolet Spectrometer Experiment (UVS)Experiment (UVS)The star The star δδ Scorpii occulted Scorpii occultedMaximum resolution of 0.1 km Maximum resolution of 0.1 km (PPS) and 3.5 km (UVS)(PPS) and 3.5 km (UVS)MethodsMethods20 kmSpiral Density WavesSpiral Density WavesPPSDensity Waves in the A ringPPSRSS XRSS S0Log S (σ cm4/s2)001122000000000000000011112222Optical DepthOptical DepthOptical DepthF (cy/km)F (cy/km)F (cy/km)111Calculated Surface Mass Densities From Spiral Density WavesRANGE (km)Surface Mass Density (g/cm2)246810120Feature SearchFeature SearchSearched C ring and Searched C ring and Cassini Division for Cassini Division for possible wave possible wave formations formations Two promising Two promising features appeared in features appeared in the Cassini Divisionthe Cassini DivisionOptical DepthFrequency (cycles/km)Frequency (cycles/km)Possible Density Wave Possible Density Wave Prometheus 5:4 Prometheus 5:4 located in the Cassini located in the Cassini Division at 120,302 km Division at 120,302 km Surface mass density Surface mass density measured in all three measured in all three data setsdata setsSurface mass density Surface mass density of ~30 g/cmof ~30 g/cm22Very high value for Very high value for Cassini DivisionCassini DivisionRange (km)1.1..-.Frequency (cycles/km)Prometheus 5:4 Surface Mass Prometheus 5:4 Surface Mass Density ResultsDensity ResultsRSS X BandFrequency (cycles/km).....12Mimas 4:1Mimas 4:1Located in the C ring Located in the C ring at 74892 kmat 74892 km16 km long wavetrain16 km long wavetrainPreviously calculated Previously calculated surface mass density surface mass density 1.0 +- 0.1 g/cm1.0 +- 0.1 g/cm22 and and 1.1 +- 0.1 g/cm1.1 +- 0.1 g/cm22Our calculated Our calculated surface mass density surface mass density ~5 g/cm~5 g/cm227.....Optical DepthThe GapThe Gap1.1..-.Frequency (cycles/km)Range (km)WakesWakesCaused by moonlets Caused by moonlets embedded in ringsembedded in ringsSimilar to boat traveling Similar to boat traveling through waterthrough waterWake features can be Wake features can be modeled based upon modeled based upon position of moonposition of moonPanPanLocated in the Encke Gap Located in the Encke Gap in Saturn’s A ringin Saturn’s A ringApproximately 10 km in Approximately 10 km in diameterdiameterDiscovered in 1990 using Discovered in 1990 using Voyager occultation dataVoyager occultation dataPossible Wakes near 119950 kmPossible Wakes near 119950 kmSatellite located somewhere near 119950 kmSatellite located somewhere near 119950 kmGap is about half the size of Encke GapGap is about half the size of Encke GapPossible wakes visible in both RSS and PPS dataPossible wakes visible in both RSS and PPS dataOptical Depth1..2..- .11Possible Wake?Possible Wake?Wake Fits Wake Fits RSS inner fit θ = 295º RSS outer fit θ = 65ºPPS inner fit θ = 247º PPS outer fit θ = 113ºIrregular StructureIrregular StructureSources of Irregular Structure Sources of Irregular Structure Ballistic Transport from meteoritic collisionsBallistic Transport from meteoritic collisions100 km wavelengths100 km wavelengthsC Ring and Inner B RingC Ring and Inner B RingDurisen, R.H. An Instability in Planetary Rings Due to Ballistic Transport. Durisen, R.H. An Instability in Planetary Rings Due to Ballistic Transport. IcarusIcarus 115, 66-85 115, 66-85 (1995).(1995).Ring Particle AssembliesRing Particle AssembliesUp to 50 - 100 km wavelengthsUp to 50 - 100 km wavelengthsB RingB RingTremaine, S. On the Origin of Irregular Structure in Saturn’s Rings. Tremaine, S. On the Origin of Irregular Structure in Saturn’s Rings. The Astronomical JournalThe Astronomical Journal 125, 894 – 901 (2003).125, 894 – 901 (2003).Inner B Ring – Large StructureInner

View Full Document
Download Wavelike Structure in Saturn’s Rings
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...

Join to view Wavelike Structure in Saturn’s Rings and access 3M+ class-specific study document.

We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Wavelike Structure in Saturn’s Rings 2 2 and access 3M+ class-specific study document.


By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?