Direct Evidence for Gravitational Instability and Moonlet Formation in Saturn's Rings
Open accessAbstract
New images from the Cassini spacecraft reveal optically thick clumps, capable of casting shadows, and associated structures in regions of Saturn's F ring that have recently experienced close passage by the adjacent moon Prometheus. Using these images and modeling, we show that Prometheus' perturbations create regions of enhanced density and low relative velocity that are susceptible to gravitational instability and the formation of distended, yet long-lived, gravitationally coherent clumps. Subsequent collisional damping of these low-density clumps may facilitate their collapse into ∼10–20 km contiguous moonlets. The observed behavior of the F ring is analogous to the case of a marginally stable gas disk being driven to instability and collapse via perturbations from an embedded gas giant planet.
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
Observations and models suggest moonlets can still form due to localised gravitational instabilities in Saturn's F ring.
“Yet, observations and models (Beurle et al., 2010;Sutton 2018) suggest moonlets can still form due to localised gravitational instabilities.”
From A Self-Gravitating Exoring Around J1407b and Implications for In-Situ Exomoon Formation (2022) · cites this paper as Beurle et al., 2010
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Cites
On the Gravitational Stability of a Disk of Stars
Toomre, A. (1964) · The Astrophysical Journal · doi:10.1086/147861 · Cited by 3,349 · cited 1× · see citing works
“Note that this is equivalent to the conditions specified by the Toomre parameter (Toomre 1964; Karjalainen & Salo 2004; Lewis & Stewart 2009) frequently used in the context of stability in disks.3 3 The Toomre stability parameter (Q = vΩ/πGΣ, where Σ and v are the disk’s surface density and…”
MethodRapid planetesimal formation in turbulent circumstellar disks
Johansen, A., Oishi, J., Low, M.-M. M., Klahr, H., Henning, T., & Youdin, A. (2007) · Nature · doi:10.1038/nature06086 · Cited by 991 · see citing works
The formation of planetesimals.
Goldreich, P., & Ward, W. (1973) · The Astrophysical Journal · doi:10.1086/152291 · Cited by 790 · see citing works
Porco, C., West, R., Squyres, S., McEwen, A., Thomas, P., Murray, C., Delgenio, A., Ingersoll, A., Johnson, T., Neukum, G., et al. (2004) · Space Science Reviews · doi:10.1007/s11214-004-1456-7 · Cited by 402 · see citing works
Toward Planetesimals: Dense Chondrule Clumps in the Protoplanetary Nebula
Cuzzi, J. N., Hogan, R. C., & Shariff, K. (2008) · The Astrophysical Journal · doi:10.1086/591239 · Cited by 386 · see citing works
Cassini Imaging Science: Initial Results on Saturn's Rings and Small Satellites
Porco, C., Baker, E., Barbara, J., Beurle, K., Brahic, A., Burns, J., Charnoz, S., Cooper, N., Dawson, D., Genio, A. D., et al. (2005) · Science · doi:10.1126/science.1108056 · Cited by 222 · see citing works
Self‐gravity wakes in Saturn's A ring measured by stellar occultations from Cassini
Colwell, J. E., Esposito, L. W., & Sremčević, M. (2006) · Geophysical Research Letters · doi:10.1029/2005gl025163 · Cited by 106 · see citing works
Charged particle depletion surrounding Saturn's F ring: Evidence for a moonlet belt?
Cuzzi, J. N., & Burns, J. A. (1988) · Icarus · doi:10.1016/0019-1035(88)90043-7 · Cited by 103 · see citing works
Satellite “wakes” and the orbit of the Encke Gap moonlet
Showalter, M. R., Cuzzi, J. N., Marouf, E. A., & Esposito, L. W. (1986) · Icarus · doi:10.1016/0019-1035(86)90160-0 · Cited by 102 · see citing works
Accretion in the Roche Zone: Coexistence of Rings and Ringmoons
Canup, R. M., & Esposito, L. W. (1995) · Icarus · doi:10.1006/icar.1995.1026 · Cited by 98 · see citing works
Self-Gravity Wake Structures in Saturn's A Ring Revealed byCassiniVIMS
Hedman, M. M., Nicholson, P. D., Salo, H., Wallis, B., Buratti, B. J., Baines, K. H., Brown, R. H., & Clark, R. N. (2007) · The Astronomical Journal · doi:10.1086/516828 · Cited by 96 · see citing works
Spitale, J. N., Jacobson, R. A., Porco, C. C., & Owen, W. M. (2006) · The Astronomical Journal · doi:10.1086/505206 · Cited by 87 · see citing works
A numerical study of Saturn's F-ring
Showalter, M. R., & Burns, J. A. (1982) · Icarus · doi:10.1016/0019-1035(82)90013-6 · Cited by 84 · see citing works
Porco, C. C., Weiss, J. W., Richardson, D. C., Dones, L., Quinn, T., & Throop, H. (2008) · The Astronomical Journal · doi:10.1088/0004-6256/136/5/2172 · Cited by 71 · see citing works
The determination of the structure of Saturn’s F ring by nearby moonlets
Murray, C. D., Beurle, K., Cooper, N. J., Evans, M. W., Williams, G. A., & Charnoz, S. (2008) · Nature · doi:10.1038/nature06999 · Cited by 69 · see citing works
Early planet formation as a trigger for further planet formation
Armitage, P. J., & Hansen, B. M. S. (1999) · Nature · doi:10.1038/45179 · Cited by 65 · see citing works
Saturn's F Ring: Kinematics and Particle Sizes from Stellar Occultation Studies
Bosh, A., Olkin, C., French, R., & Nicholson, P. (2002) · Icarus · doi:10.1006/icar.2002.6791 · Cited by 65 · see citing works
How Prometheus creates structure in Saturn's F ring
Murray, C. D., Chávez, C. E., Beurle, K., Cooper, N. J., Evans, M. W., Burns, J. A., & Porco, C. C. (2005) · Nature · doi:10.1038/nature04212 · Cited by 62 · see citing works
Gravitational accretion of particles in Saturn's rings
Karjalainen, R., & Salo, H. (2004) · Icarus · doi:10.1016/j.icarus.2004.05.022 · Cited by 60 · see citing works
Moonlets and clumps in Saturn's F ring
Esposito, L. W., Meinke, B. K., Colwell, J. E., Nicholson, P. D., & Hedman, M. M. (2007) · Icarus · doi:10.1016/j.icarus.2007.10.001 · Cited by 56 · see citing works
Moonlet Collisions and the Effects of Tidally Modified Accretion in Saturn's F Ring
Barbara, J. (2002) · Icarus · doi:10.1006/icar.2002.6962 · Cited by 54 · see citing works
Lewis, M. C., & Stewart, G. (2009) · Icarus · doi:10.1016/j.icarus.2008.09.009 · Cited by 54 · see citing works
Cassini Discovers a Kinematic Spiral Ring Around Saturn
Charnoz, S., Porco, C. C., Déau, E., Brahic, A., Spitale, J. N., Bacques, G., & Baillié, K. (2005) · Science · doi:10.1126/science.1119387 · Cited by 52 · see citing works
Expectations for Cassini observations of ring material with nearby moons
Lewis, M. C., & Stewart, G. R. (2005) · Icarus · doi:10.1016/j.icarus.2005.04.009 · Cited by 36 · see citing works
Physical collisions of moonlets and clumps with the Saturn's F-ring core
Charnoz, S. (2009) · Icarus · doi:10.1016/j.icarus.2008.12.036 · Cited by 23 · see citing works
Rapid formation of gas giants, ice giants and super-Earths
Boss, A. (2008) · Physica Scripta · doi:10.1088/0031-8949/2008/t130/014020 · Cited by 7 · see citing works
Flagged first, then by citations
Research works printed but not linked: 2
- Murray, C. D., & Dermott, S. F. 1999, Solar System Dynamics (Cambridge: Cambridge Univ. Press), 158
- Williams, G. A. 2009, PhD thesis, Queen Mary Univ. of London
Cited by
Sorted by citations
Vision and Voyages for Planetary Science in the Decade 2013-2022
National Research Council (2011) · National Academies Press eBooks · doi:10.17226/13117 · Cited by 357 · see citing works
A dense ring of the trans-Neptunian object Quaoar outside its Roche limit
Morgado, B. E., Sicardy, B., Braga-Ribas, F., Ortiz, J. L., Salo, H., Vachier, F., Desmars, J., Pereira, C. L., Santos-Sanz, P., Sfair, R., et al. (2023) · Nature · doi:10.1038/s41586-022-05629-6 · Cited by 95 · see citing works
Cassini-Huygens’ exploration of the Saturn system: 13 years of discovery
Spilker, L. (2019) · Science · doi:10.1126/science.aat3760 · Cited by 65 · see citing works
CASSINI UVIS STELLAR OCCULTATION OBSERVATIONS OF SATURN's RINGS
Colwell, J. E., Esposito, L. W., Jerousek, R. G., Sremčević, M., Pettis, D., & Bradley, E. T. (2010) · The Astronomical Journal · doi:10.1088/0004-6256/140/6/1569 · Cited by 55 · see citing works
Tiscareno, M. S. (2013) · Planets, Stars and Stellar Systems · doi:10.1007/978-94-007-5606-9_7 · Cited by 37 · see citing works
A predator–prey model for moon-triggered clumping in Saturn’s rings
Esposito, L. W., Albers, N., Meinke, B. K., Sremčević, M., Madhusudhanan, P., Colwell, J. E., & Jerousek, R. G. (2011) · Icarus · doi:10.1016/j.icarus.2011.09.029 · Cited by 32 · see citing works
COLLISIONAL DISRUPTION OF GRAVITATIONAL AGGREGATES IN THE TIDAL ENVIRONMENT
Hyodo, R., & Ohtsuki, K. (2014) · The Astrophysical Journal · doi:10.1088/0004-637x/787/1/56 · Cited by 20 · see citing works
Hedman, M. M., Nicholson, P. D., Showalter, M. R., Brown, R. H., Buratti, B. J., Clark, R. N., Baines, K. H., & Sotin, C. (2011) · Icarus · doi:10.1016/j.icarus.2011.02.025 · Cited by 27 · see citing works
Saturn’s F ring and shepherd satellites a natural outcome of satellite system formation
Hyodo, R., & Ohtsuki, K. (2015) · Nature Geoscience · doi:10.1038/ngeo2508 · Cited by 21 · see citing works
Classification of F ring features observed in Cassini UVIS occultations
Meinke, B. K., Esposito, L. W., Albers, N., & Sremčević, M. (2012) · Icarus · doi:10.1016/j.icarus.2011.12.020 · Cited by 26 · see citing works
Close-range remote sensing of Saturn’s rings during Cassini’s ring-grazing orbits and Grand Finale
Tiscareno, M., Nicholson, P., Cuzzi, J., Spilker, L., Murray, C., Hedman, M., Colwell, J., Burns, J., Brooks, S., Clark, R., et al. (2019) · Science · doi:10.1126/science.aau1017 · Cited by 26 · see citing works
DETECTION OF LOW-VELOCITY COLLISIONS IN SATURN'S F RING
Attree, N. O., Murray, C. D., Cooper, N. J., & Williams, G. A. (2012) · The Astrophysical Journal Letters · doi:10.1088/2041-8205/755/2/l27 · Cited by 21 · see citing works
The brightening of Saturn’s F ring
French, R., Showalter, M. R., Sfair, R., Argüelles, C. A., Pajuelo, M., Becerra, P., Hedman, M. M., & Nicholson, P. D. (2012) · Icarus · doi:10.1016/j.icarus.2012.02.020 · Cited by 21 · see citing works
Saturn’s F Ring core: Calm in the midst of chaos
Cuzzi, J. N., Whizin, A. D., Hogan, R. C., Dobrovolskis, A. R., Luke Dones, B., Showalter, M. R., Colwell, J. E., & Scargle, J. D. (2014) · Icarus · doi:10.1016/j.icarus.2013.12.027 · Cited by 18 · see citing works
Cuzzi, J. N., Filacchione, G., & Marouf, E. A. (2018) · Cambridge University Press eBooks · doi:10.1017/9781316286791.003 · Cited by 18 · see citing works
A survey of low-velocity collisional features in Saturn’s F ring
Attree, N. O., Murray, C. D., Williams, G. A., & Cooper, N. J. (2013) · Icarus · doi:10.1016/j.icarus.2013.09.008 · Cited by 15 · see citing works
The discovery and dynamical evolution of an object at the outer edge of Saturn’s A ring
Murray, C., Cooper, N., Williams, G., Attree, N., & Boyer, J. S. (2014) · Icarus · doi:10.1016/j.icarus.2014.03.024 · Cited by 11 · see citing works
Recipe for making Saturn's rings
Crida, A., & Charnoz, S. (2010) · Nature · doi:10.1038/nature09738 · Cited by 13 · see citing works
Aggregates in the strength and gravity regime: Particles sizes in Saturn’s rings
Guimaraes, A. H. F., Albers, N., Spahn, F., Seiß, M., Vieira-Neto, E., & Brilliantov, N. (2012) · Icarus · doi:10.1016/j.icarus.2012.06.005 · Cited by 12 · see citing works
Review of Saturn’s icy moons following the Cassini mission
Dougherty, M. K., & Spilker, L. J. (2018) · Reports on Progress in Physics · doi:10.1088/1361-6633/aabdfb · Cited by 11 · see citing works
Stability of co-orbital ring material with applications to the Janus–Epimetheus system
Williams, G. A., & Murray, C. D. (2010) · Icarus · doi:10.1016/j.icarus.2010.11.038 · Cited by 8 · see citing works
Analysis of clumps in Saturn’s F ring from Voyager and Cassini
French, R., Hicks–Jalali, S., Showalter, M. R., Antonsen, A. K., & Packard, D. R. (2014) · Icarus · doi:10.1016/j.icarus.2014.06.035 · Cited by 7 · see citing works
The Origin and Composition of Saturn’s Ring Moons
Ciarniello, M., Filacchione, G., Nicholson, P. D., Hedman, M., Charnoz, S., Cuzzi, J., Moutamid, M. E., Hendrix, A., Rambaux, N., Miller, K. E., et al. (2024) · Space Science Reviews · doi:10.1007/s11214-024-01103-z · Cited by 7 · see citing works
Gravitational Vortices And Clump Formation In Saturn's F ring During An Encounter With Prometheus
Sutton, P. J., & Kusmartsev, F. (2013) · Scientific Reports · doi:10.1038/srep01276 · Cited by 6 · see citing works
Griv, E. (2011) · The Astrophysical Journal · doi:10.1088/0004-637x/733/1/43 · Cited by 5 · see citing works
Sutton, P. J. (2019) · Monthly Notices of the Royal Astronomical Society · doi:10.1093/mnras/stz563 · Cited by 5 · see citing works
“This could be analogous to Saturn’s F ring where a nearby moon Prometheus disrupts the F ring causing local gravitational instabilities and subsequent small moonlets, which were found by the Cassini spacecraft (Murray et al 2005; Beurle et al 2010; Sutton 2018).”
BackgroundPlanetary Rings: A Post-Equinox View
Esposito, L. W. (2018) · Cited by 5 · see citing works
The vertical structure of the F ring of Saturn from ring-plane crossings
Scharringhausen, B., & Nicholson, P. (2013) · Icarus · doi:10.1016/j.icarus.2013.08.010 · Cited by 6 · see citing works
Mathematical analysis of a model for moon-triggered clumping in Saturn’s rings
Torres, P. J., Madhusudhanan, P., & Esposito, L. W. (2013) · Physica D Nonlinear Phenomena · doi:10.1016/j.physd.2013.06.002 · Cited by 4 · see citing works
Sutton, P. J., & Kusmartsev, F. V. (2014) · Monthly Notices of the Royal Astronomical Society · doi:10.1093/mnras/stt2462 · Cited by 4 · see citing works
Rings in the Solar System: A Short Review
Charnoz, S., Crida, A., & Hyodo, R. (2018) · Springer eBooks · doi:10.1007/978-3-319-30648-3_54-1 · Cited by 4 · see citing works
Rings in the Solar System: a short review
Charnoz, S., Crida, A., & Hyodo, R. (2018) · Springer eBooks · doi:10.1007/978-3-319-55333-7_54 · Cited by 4 · see citing works
A Self-Gravitating Exoring Around J1407b and Implications for In-Situ Exomoon Formation
Sutton, P. J., Albery, B., & Muff, J. (2022) · Frontiers in Astronomy and Space Sciences · doi:10.3389/fspas.2022.819933 · Cited by 2 · see citing works
“Yet, observations and models (Beurle et al., 2010; Sutton 2018) suggest moonlets can still form due to localised gravitational instabilities.”
On the Tidal Environment of an Outwardly Migrating F Ring
Sutton, P. J. (2018) · Monthly Notices of the Royal Astronomical Society · doi:10.1093/mnras/sty995 · Cited by 2 · see citing works
Mustill, A. J., Davies, M. B., & Kenworthy, M. A. (2024) · Monthly Notices of the Royal Astronomical Society · doi:10.1093/mnras/stae1074 · Cited by 2 · see citing works
A curious ringlet that shares Prometheus’ orbit but precesses like the F ring
Hedman, M. M., & Carter, B. J. (2016) · Icarus · doi:10.1016/j.icarus.2016.08.024 · Cited by 2 · see citing works
Prometheus Induced Vorticity in Saturn’s F Ring
Sutton, P. J., & Kusmartsev, F. V. (2016) · Earth Moon and Planets · doi:10.1007/s11038-016-9494-1 · Cited by 1 · see citing works
A simple model for the location of Saturn’s F ring
Benet, L., & Jorba, À. (2016) · Icarus · doi:10.1016/j.icarus.2016.12.006 · Cited by 1 · see citing works
Prometheus induced vorticity in Saturn's F ring
Sutton, P. J., & (17216929), F. V. K. (2019) · Figshare · Cited by 1 · see citing works
A planetary ring in a surprising place
Hedman, M. M. (2023) · Nature · doi:10.1038/d41586-023-00270-3 · Cited by 1 · see citing works
Moran, M. E. (2013) · Springer eBooks · doi:10.1007/978-1-4614-8196-6_17
Solar system: Recipe for making Saturn's rings
Crida, A., & Charnoz, S. (2010) · Nature · doi:10.1038/468903a
Lianlunthang, T. P., Baruah, M., Mahato, R., & Thakur, S. K. (2026) · New Astronomy · doi:10.1016/j.newast.2026.102594
- Authors
- Beurle, K., Murray, C. D., Williams, G. A., Evans, M. W., Cooper, N. J., & Agnor, C. B.
- Affiliations
- Queen Mary University of London (GB)
- Corresponding author
- Murray, C. D.
- Agnor, C. B.
- Venue
- The Astrophysical Journal
- Publisher
- American Astronomical Society
- Published
- 2010-07-14
- Volume
- 718
- Issue
- 2
- Pages
- L176-L180
- ISSN
- 2041-8205 (ISSN-L)
- 2041-8213
- OpenAlex
- W1972262640
- Cited by
- 43
- References
- 26
- Citations by year
- 2026: 1 · 2024: 2 · 2023: 2 · 2022: 1 · 2019: 4 · 2018: 6 · 2016: 3 · 2015: 1 · 2014: 5 · 2013: 6 · 2012: 4
- FWCI
- 3.22
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- The Astrophysical Journal Letters (publishedVersion)
- Funders
- National Aeronautics and Space Administration
- Science and Technology Facilities Council (ST/F002696/1)
- Topics
- Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Astro and Planetary Science
- Physical Sciences › Engineering › Aerospace Engineering › Space Satellite Systems and Control
- Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Astrophysics and Star Formation Studies
- Keywords
- moonlets, gravitational instability, Prometheus, ring perturbations, collisional damping, ring dynamics, Cassini imaging
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
