Ring-satellite interactions and orbital evolution in the Saturn system
Lead Research Organisation:
Queen Mary University of London
Department Name: Astronomy Unit
Abstract
Saturn has the most spectacular and, thanks to the Cassini spacecraft, the most studied rings in the solar system. The results to date from Cassini show a ring system that is continually evolving under a variety of processes ranging from subtle gravitational interactions with perturbing moons, to impacts at several tens of metres per second between parts of the rings and moonlets which may be formed in the rings themselves. As the closest astrophysical disk to Earth, Saturn's rings represent a unique laboratory in which to study the same processes (but with different starting conditions) that give rise to planets. The ready availability of Cassini data combined with a basic understanding of how rings and moons form and evolve has revolutionised the study of planetary rings. Fundamental questions about the lifetime and evolution of the ring system of Saturn can be answered by understanding the processes by which ring material accumulates into moonlets and how small moons gravitationally interact with the rings. The proposed research will study the mechanisms by which gravitational instability in a ring can be induced by a passing moon using the narrow F ring and its shepherding moon, Prometheus, as a paradigm. We believe that there is evidence in the Cassini images of a process by which moonlets can form and evolve on timescales of months to years. Furthermore, we can model this process in numerical simulations and test our results by comparison with the actual rings and accompanying moonlets seen in the Cassini data. There is already evidence that embedded moonlets in Saturn's A ring are undergoing slow changes in their orbits under the gravitational effect of adjacent ring material and this is just one aspect of a more general problem relating to the lifetime of Saturn's rings: The current best estimate of the lifetime of the rings suggests that expanding satellite orbits and contracting ring orbits will mean that the rings can only survive for ~400My, which is <10% of the age of the solar system. Using orbital data extracted from long-term monitoring of satellites with Cassini images we intend to quantify this effect. We will also be investigating a possible means of 'locking' the ring system so that angular momentum is fed to a more massive, exterior satellite such as Mimas.
People |
ORCID iD |
Carl Murray (Principal Investigator) |
Publications
Murray Carl
(2012)
The structure of Saturn's F ring
in EGU General Assembly 2012
Murray Carl
(2012)
The morphology of Saturn's F ring
in Bulletin of the American Astronomical Society
Tiscareno Matthew
(2011)
Observations of ejecta clouds produced by impacts onto Saturn's rings
in EPSC-DPS Joint Meeting 2011
Description | The discovery of impact events in Saturn's rings gives an estimate of the flux of objects in the outer solar system. The impact structures show evidence that the impactors are themselves multiple objects. |
Exploitation Route | The nature of impacting objects will be of use to people modelling impact events on different scales. |
Sectors | Education,Other |
Description | International Exchanges Scheme |
Amount | £11,606 (GBP) |
Funding ID | IE110421 |
Organisation | The Royal Society |
Sector | Charity/Non Profit |
Country | United Kingdom |
Start | 01/2012 |
End | 12/2013 |
Description | School Visit (Charlton) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Type Of Presentation | Keynote/Invited Speaker |
Geographic Reach | Regional |
Primary Audience | Schools |
Results and Impact | I gave two talks about Cassini and space to around 100 pupils at this special needs school in Charlton. The audience were were very appreciative. |
Year(s) Of Engagement Activity | 2011 |
Description | School Visit (Woodford) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Type Of Presentation | Keynote/Invited Speaker |
Geographic Reach | Regional |
Primary Audience | Schools |
Results and Impact | Careers talk to sixth formers at Bancroft's School, incorporating Cassini results. Dissemination of Cassini results. |
Year(s) Of Engagement Activity | 2011 |
Description | Seminar (Cardiff) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Type Of Presentation | Keynote/Invited Speaker |
Geographic Reach | Regional |
Primary Audience | Other academic audiences (collaborators, peers etc.) |
Results and Impact | Seminar about Cassini ring results at Cardiff University, School of Physics and Astronomy. Dissemination of Cassini results. |
Year(s) Of Engagement Activity | 2011 |
Description | Seminar at UC Santa Barbara, USA |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Type Of Presentation | Keynote/Invited Speaker |
Geographic Reach | Regional |
Primary Audience | Other academic audiences (collaborators, peers etc.) |
Results and Impact | Audience of about 20 astronomers at the UC Santa Barbara camps. Dissemination of Cassini results and useful discussions with planetary scientists. |
Year(s) Of Engagement Activity | 2012 |
Description | Talk at Barts Cancer Institute (London) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Type Of Presentation | Keynote/Invited Speaker |
Geographic Reach | Regional |
Primary Audience | Health professionals |
Results and Impact | Invited talk about Cassini to cancer researchers. Dissemination of Cassini results. |
Year(s) Of Engagement Activity | 2011 |
Description | Talk at Maths Taster Course (Queen Mary) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Type Of Presentation | Keynote/Invited Speaker |
Geographic Reach | Regional |
Primary Audience | Schools |
Results and Impact | Talk to sixth formers about how maths is used in astronomy with emphasis on Cassini results. Dissemination of Cassini results. |
Year(s) Of Engagement Activity | 2011 |
Description | Talk at Rings Workshop (Cornell Univ.) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Type Of Presentation | Paper Presentation |
Geographic Reach | International |
Primary Audience | Other academic audiences (collaborators, peers etc.) |
Results and Impact | Talk on Cassini F ring results at workshop at Cornell University. Dissemination of Cassini results; initiation of collaborations. |
Year(s) Of Engagement Activity | 2011 |
Description | Talk at the Institute of Physics (Aldermaston) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Type Of Presentation | Keynote/Invited Speaker |
Geographic Reach | Regional |
Primary Audience | Other academic audiences (collaborators, peers etc.) |
Results and Impact | Talk to local IoP members and the general public about Cassini results. Dissemination of Cassini results. |
Year(s) Of Engagement Activity | 2011 |
Description | Talk to NQTs (Pimlico) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | Yes |
Type Of Presentation | Keynote/Invited Speaker |
Geographic Reach | Regional |
Primary Audience | Other academic audiences (collaborators, peers etc.) |
Results and Impact | Talk to about 20 NQTs about Cassini results and how to use them in the classroom. Talk was recorded and slides provided for podcast. |
Year(s) Of Engagement Activity | 2012 |
Description | Talk to local astronomical society (Greenwich) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Type Of Presentation | Keynote/Invited Speaker |
Geographic Reach | Regional |
Primary Audience | Public/other audiences |
Results and Impact | This was the third talk I have given to the appreciative audience of around 50 people at the Flamsteed Astronomical Society. Dissemination of Cassini results. |
Year(s) Of Engagement Activity | 2011 |
Description | Talk to local astronomical society (Orpington) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Type Of Presentation | Keynote/Invited Speaker |
Geographic Reach | Regional |
Primary Audience | Public/other audiences |
Results and Impact | Talk about Cassini to about 50 members of Orpington Astronomical Society. Dissemination of Cassini results. |
Year(s) Of Engagement Activity | 2012 |
Description | Talk to local astronomical society (Reading) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Type Of Presentation | Keynote/Invited Speaker |
Geographic Reach | Regional |
Primary Audience | Public/other audiences |
Results and Impact | Audience of about 40 amateur astronomers and members of the public at Reading Astronomical Society. Dissemination of Cassini results. |
Year(s) Of Engagement Activity | 2012 |