TY  - GEN
A1  - Grün, Eberhard
A1  - de Pater, Imke
A1  - Showalter, Mark
A1  - Spahn, Frank
A1  - Srama, Ralf
T1  - Physics of dusty rings: History and perspective
BT  - Foreword
T2  - Planetary and space science
Y1  - 2006
U6  - https://doi.org/10.1016/j.pss.2006.05.005
SN  - 0032-0633
VL  - 54
IS  - 9-10
SP  - 837
EP  - 843
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Hsu, Hsiang-Wen
A1  - Schmidt, Jürgen
A1  - Kempf, Sascha
A1  - Postberg, Frank
A1  - Moragas-Klostermeyer, Georg
A1  - Seiss, Martin
A1  - Hoffmann, Holger
A1  - Burton, Marcia
A1  - Ye, ShengYi
A1  - Kurth, William S.
A1  - Horanyi, Mihaly
A1  - Khawaja, Nozair
A1  - Spahn, Frank
A1  - Schirdewahn, Daniel
A1  - Moore, Luke
A1  - Cuzzi, Jeff
A1  - Jones, Geraint H.
A1  - Srama, Ralf
T1  - In situ collection of dust grains falling from Saturn’s rings into its atmosphere
JF  - Science
N2  - Saturn’s main rings are composed of >95% water ice, and the nature of the remaining few percent has remained unclear. The Cassini spacecraft’s traversals between Saturn and its innermost D ring allowed its cosmic dust analyzer (CDA) to collect material released from the main rings and to characterize the ring material infall into Saturn. We report the direct in situ detection of material from Saturn’s dense rings by the CDA impact mass spectrometer. Most detected grains are a few tens of nanometers in size and dynamically associated with the previously inferred “ring rain.” Silicate and water-ice grains were identified, in proportions that vary with latitude. Silicate grains constitute up to 30% of infalling grains, a higher percentage than the bulk silicate content of the rings.
Y1  - 2018
U6  - https://doi.org/10.1126/science.aat3185
SN  - 0036-8075
SN  - 1095-9203
VL  - 362
IS  - 6410
SP  - 49
EP  - +
PB  - American Assoc. for the Advancement of Science
CY  - Washington
ER  - 
TY  - JOUR
A1  - Spahn, Frank
A1  - Schmidt, Jürgen
A1  - Albers, Nicole
A1  - Hörning, Marcel
A1  - Makuch, Martin
A1  - Seiß, Martin
A1  - Kempf, Sascha
A1  - Srama, Ralf
A1  - Dikarev, Valeri
A1  - Helfert, Stefan
A1  - Moragas-Klostermeyer, Georg
A1  - Krivov, Alexander V.
A1  - Sremcevic, Miodrag
A1  - Tuzzolino, Anthony J.
A1  - Economou, Thanasis
A1  - Grün, Eberhard
T1  - Cassini dust measurements at Enceladus and implications for the origin of the E ring
Y1  - 2006
UR  - http://www.sciencemag.org/content/311/5766/1416.full
U6  - https://doi.org/10.1126/science.1121375
ER  - 
TY  - JOUR
A1  - Srama, Ralf
A1  - Ahrens, Thomas J.
A1  - Altobelli, Nicolas
A1  - Auer, S.
A1  - Bradley, J. G.
A1  - Burton, M.
A1  - Dikarev, V. V.
A1  - Economou, T.
A1  - Fechtig, Hugo
A1  - Görlich, M.
A1  - Grande, M.
A1  - Graps, Amara
A1  - Grün, Eberhard
A1  - Havnes, Ove
A1  - Helfert, Stefan
A1  - Horanyi, Mihaly
A1  - Igenbergs, E.
A1  - Jessberger, Elmar K.
A1  - Johnson, T. V.
A1  - Kempf, Sascha
A1  - Krivov, Alexander v.
A1  - Krüger, Harald
A1  - Mocker-Ahlreep, Anna
A1  - Moragas-Klostermeyer, Georg
A1  - Lamy, Philippe
A1  - Landgraf, Markus
A1  - Linkert, Dietmar
A1  - Linkert, G.
A1  - Lura, F.
A1  - McDonnell, J. A. M.
A1  - Moehlmann, Dirk
A1  - Morfill, Gregory E.
A1  - Muller, M.
A1  - Roy, M.
A1  - Schafer, G.
A1  - Schlotzhauer, G.
A1  - Schwehm, Gerhard H.
A1  - Spahn, Frank
A1  - Stübig, M.
A1  - Svestka, Jiri
A1  - Tschernjawski, V
T1  - The Cassini Cosmic Dust Analyzer
N2  - The Cassini-Huygens Cosmic Dust Analyzer (CDA) is intended to provide direct observations of dust grains with masses between 10(-19) and 10(-9) kg in interplanetary space and in the jovian and saturnian systems, to investigate their physical, chemical and dynamical properties as functions of the distances to the Sun, to Jupiter and to Saturn and its satellites and rings, to study their interaction with the saturnian rings, satellites and magnetosphere. Chemical composition of interplanetary meteoroids will be compared with asteroidal and cometary dust, as well as with Saturn dust, ejecta from rings and satellites. Ring and satellites phenomena which might be effects of meteoroid impacts will be compared with the interplanetary dust environment. Electrical charges of particulate matter in the magnetosphere and its consequences will be studied, e.g. the effects of the ambient plasma and the magnetic held on the trajectories of dust particles as well as fragmentation of particles due to electrostatic disruption. The investigation will be performed with an instrument that measures the mass, composition, electric charge, speed, and flight direction of individual dust particles. It is a highly reliable and versatile instrument with a mass sensitivity 106 times higher than that of the Pioneer 10 and I I dust detectors which measured dust in the saturnian system. The Cosmic Dust Analyzer has significant inheritance from former space instrumentation developed for the VEGA, Giotto, Galileo, and Ulysses missions. It will reliably measure impacts from as low as I impact per month up to 104 impacts per second. The instrument weighs 17 kg and consumes 12 W, the integrated time-of-flight mass spectrometer has a mass resolution of up to 50. The nominal data transmission rate is 524 bits/s and varies between 50 and 4192 bps
Y1  - 2004
SN  - 0038-6308
ER  - 
TY  - JOUR
A1  - Ye, S. -Y.
A1  - Kurth, William S.
A1  - Hospodarsky, George B.
A1  - Persoon, Ann M.
A1  - Gurnett, Don A.
A1  - Morooka, Michiko
A1  - Wahlund, Jan-Erik
A1  - Hsu, Hsiang-Wen
A1  - Seiss, Martin
A1  - Srama, Ralf
T1  - Cassini RPWS dust observation near the Janus/Epimetheus orbit
JF  - Journal of geophysical research : Space physics
N2  - During the Ring Grazing orbits near the end of Cassini mission, the spacecraft crossed the equatorial plane near the orbit of Janus/Epimetheus (similar to 2.5 Rs). This region is populated with dust particles that can be detected by the Radio and Plasma Wave Science (RPWS) instrument via an electric field antenna signal. Analysis of the voltage waveforms recorded on the RPWS antennas provides estimations of the density and size distribution of the dust particles. Measured RPWS profiles, fitted with Lorentzian functions, are shown to be mostly consistent with the Cosmic Dust Analyzer, the dedicated dust instrument on board Cassini. The thickness of the dusty ring varies between 600 and 1,000 km. The peak location shifts north and south within 100 km of the ring plane, likely a function of the precession phase of Janus orbit.
KW  - Saturn
KW  - dust
KW  - ring
Y1  - 2018
U6  - https://doi.org/10.1029/2017JA025112
SN  - 2169-9380
SN  - 2169-9402
VL  - 123
IS  - 6
SP  - 4952
EP  - 4960
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Ye, Shengyi
A1  - Kurth, William S.
A1  - Hospodarsky, George B.
A1  - Persoon, Ann M.
A1  - Sulaiman, Ali H.
A1  - Gurnett, Don A.
A1  - Morooka, Michiko
A1  - Wahlund, Jan-Erik
A1  - Hsu, Hsiang-Wen
A1  - Sternovsky, Zoltan
A1  - Wang, Xu
A1  - Horanyi, M.
A1  - Seiss, Martin
A1  - Srama, Ralf
T1  - Dust Observations by the Radio and Plasma Wave Science Instrument During
JF  - Geophysical research letters
N2  - Plain Language Summary Cassini flew through the gap between Saturn and its rings for 22 times before plunging into the atmosphere of Saturn, ending its 20-year mission. The radio and plasma waves instrument on board Cassini helped quantify the dust hazard in this previously unexplored region. The measured density of large dust particles was much lower than expected, allowing high-value science observations during the subsequent Grand Finale orbits.
Y1  - 2018
U6  - https://doi.org/10.1029/2018GL078059
SN  - 0094-8276
SN  - 1944-8007
VL  - 45
IS  - 19
SP  - 10101
EP  - 10109
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Cuzzi, Jeff N.
A1  - Burns, Joseph A.
A1  - Charnoz, Sébastien
A1  - Clark, Roger N.
A1  - Colwell, Josh E.
A1  - Dones, Luke
A1  - Esposito, Larry W.
A1  - Filacchione, Gianrico
A1  - French, Richard G.
A1  - Hedman, Matthew M.
A1  - Kempf, Sascha
A1  - Marouf, Essam A.
A1  - Murray, Carl D.
A1  - Nicholson, Phillip D.
A1  - Porco, Carolyn C.
A1  - Schmidt, Jürgen
A1  - Showalter, Mark R.
A1  - Spilker, Linda J.
A1  - Spitale, Joseph N.
A1  - Srama, Ralf
A1  - Sremcević, Miodrag
A1  - Tiscareno, Matthew Steven
A1  - Weiss, John
T1  - An evolving view of Saturn's dynamic rings
N2  - We review our understanding of Saturn's rings after nearly 6 years of observations by the Cassini spacecraft. Saturn's rings are composed mostly of water ice but also contain an undetermined reddish contaminant. The rings exhibit a range of structure across many spatial scales; some of this involves the interplay of the fluid nature and the self-gravity of innumerable orbiting centimeter- to meter-sized particles, and the effects of several peripheral and embedded moonlets, but much remains unexplained. A few aspects of ring structure change on time scales as short as days. It remains unclear whether the vigorous evolutionary processes to which the rings are subject imply a much younger age than that of the solar system. Processes on view at Saturn have parallels in circumstellar disks.
Y1  - 2010
UR  - http://www.sciencemag.org/
U6  - https://doi.org/10.1126/science.1179118
SN  - 0036-8075
ER  - 
TY  - JOUR
A1  - Postberg, Frank
A1  - Kempf, Sascha
A1  - Schmidt, Jürgen
A1  - Brilliantov, Nikolai V.
A1  - Beinsen, Alexander
A1  - Abel, Bernd
A1  - Buck, Udo
A1  - Srama, Ralf
T1  - Sodium salts in E-ring ice grains from an ocean below the surface of Enceladus
N2  - Saturn's moon Enceladus emits plumes of water vapour and ice particles from fractures near its south pole(1-5), suggesting the possibility of a subsurface ocean(5-7). These plume particles are the dominant source of Saturn's E ring(7,8). A previous in situ analysis(9) of these particles concluded that the minor organic or siliceous components, identified in many ice grains, could be evidence for interaction between Enceladus' rocky core and liquid water(9,10). It was not clear, however, whether the liquid is still present today or whether it has frozen. Here we report the identification of a population of E-ring grains that are rich in sodium salts (similar to 0.5- 2% by mass), which can arise only if the plumes originate from liquid water. The abundance of various salt components in these particles, as well as the inferred basic pH, exhibit a compelling similarity to the predicted composition of a subsurface Enceladus ocean in contact with its rock core(11). The plume vapour is expected to be free of atomic sodium. Thus, the absence of sodium from optical spectra(12) is in good agreement with our results. In the E ring the upper limit for spectroscopy(12) is insufficiently sensitive to detect the concentrations we found.
Y1  - 2009
UR  - http://www.nature.com/nature/
U6  - https://doi.org/10.1038/Nature08046
SN  - 0028-0836
ER  - 
TY  - JOUR
A1  - Postberg, Frank
A1  - Schmidt, J.
A1  - Hillier, J.
A1  - Kempf, Sascha
A1  - Srama, Ralf
T1  - A salt-water reservoir as the source of a compositionally stratified plume on Enceladus
JF  - Nature : the international weekly journal of science
N2  - The discovery of a plume of water vapour and ice particles emerging from warm fractures ('tiger stripes') in Saturn's small, icy moon Enceladus(1-6) raised the question of whether the plume emerges from a subsurface liquid source(6-8) or from the decomposition of ice(9-12). Previous compositional analyses of particles injected by the plume into Saturn's diffuse E ring have already indicated the presence of liquid water(8), but the mechanisms driving the plume emission are still debated(13). Here we report an analysis of the composition of freshly ejected particles close to the sources. Salt-rich ice particles are found to dominate the total mass flux of ejected solids (more than 99 per cent) but they are depleted in the population escaping into Saturn's E ring. Ice grains containing organic compounds are found to be more abundant in dense parts of the plume. Whereas previous Cassini observations were compatible with a variety of plume formation mechanisms, these data eliminate or severely constrain non-liquid models and strongly imply that a salt-water reservoir with a large evaporating surface(7,8) provides nearly all of the matter in the plume.
Y1  - 2011
U6  - https://doi.org/10.1038/nature10175
SN  - 0028-0836
VL  - 474
IS  - 7353
SP  - 620
EP  - 622
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Srama, Ralf
A1  - Krueger, H.
A1  - Yamaguchi, T.
A1  - Stephan, T.
A1  - Burchell, M.
A1  - Kearsley, A. T.
A1  - Sterken, V.
A1  - Postberg, F.
A1  - Kempf, S.
A1  - Grün, Eberhard
A1  - Altobelli, Nicolas
A1  - Ehrenfreund, P.
A1  - Dikarev, V.
A1  - Horanyi, M.
A1  - Sternovsky, Zoltan
A1  - Carpenter, J. D.
A1  - Westphal, A.
A1  - Gainsforth, Z.
A1  - Krabbe, A.
A1  - Agarwal, Jessica
A1  - Yano, H.
A1  - Blum, J.
A1  - Henkel, H.
A1  - Hillier, J.
A1  - Hoppe, P.
A1  - Trieloff, M.
A1  - Hsu, S.
A1  - Mocker, A.
A1  - Fiege, K.
A1  - Green, S. F.
A1  - Bischoff, A.
A1  - Esposito, F.
A1  - Laufer, R.
A1  - Hyde, T. W.
A1  - Herdrich, G.
A1  - Fasoulas, S.
A1  - Jaeckel, A.
A1  - Jones, G.
A1  - Jenniskens, P.
A1  - Khalisi, E.
A1  - Moragas-Klostermeyer, Georg
A1  - Spahn, Frank
A1  - Keller, H. U.
A1  - Frisch, P.
A1  - Levasseur-Regourd, A. C.
A1  - Pailer, N.
A1  - Altwegg, K.
A1  - Engrand, C.
A1  - Auer, S.
A1  - Silen, J.
A1  - Sasaki, S.
A1  - Kobayashi, M.
A1  - Schmidt, J.
A1  - Kissel, J.
A1  - Marty, B.
A1  - Michel, P.
A1  - Palumbo, P.
A1  - Vaisberg, O.
A1  - Baggaley, J.
A1  - Rotundi, A.
A1  - Roeser, H. P.
T1  - SARIM PLUS-sample return of comet 67P/CG and of interstellar matter
JF  - EXPERIMENTAL ASTRONOMY
N2  - The Stardust mission returned cometary, interplanetary and (probably) interstellar dust in 2006 to Earth that have been analysed in Earth laboratories worldwide. Results of this mission have changed our view and knowledge on the early solar nebula. The Rosetta mission is on its way to land on comet 67P/Churyumov-Gerasimenko and will investigate for the first time in great detail the comet nucleus and its environment starting in 2014. Additional astronomy and planetary space missions will further contribute to our understanding of dust generation, evolution and destruction in interstellar and interplanetary space and provide constraints on solar system formation and processes that led to the origin of life on Earth. One of these missions, SARIM-PLUS, will provide a unique perspective by measuring interplanetary and interstellar dust with high accuracy and sensitivity in our inner solar system between 1 and 2 AU. SARIM-PLUS employs latest in-situ techniques for a full characterisation of individual micrometeoroids (flux, mass, charge, trajectory, composition()) and collects and returns these samples to Earth for a detailed analysis. The opportunity to visit again the target comet of the Rosetta mission 67P/Churyumov-Gerasimeenternko, and to investigate its dusty environment six years after Rosetta with complementary methods is unique and strongly enhances and supports the scientific exploration of this target and the entire Rosetta mission. Launch opportunities are in 2020 with a backup window starting early 2026. The comet encounter occurs in September 2021 and the reentry takes place in early 2024. An encounter speed of 6 km/s ensures comparable results to the Stardust mission.
KW  - Interstellar dust
KW  - Cometary dust
KW  - Churyumov Gerasimenko
KW  - Interplanetary dust
KW  - IMF
KW  - Cosmic vision
KW  - Sample return
KW  - Dust collector
KW  - Mass spectrometry
Y1  - 2012
U6  - https://doi.org/10.1007/s10686-011-9285-7
SN  - 0922-6435
SN  - 1572-9508
VL  - 33
IS  - 2-3
SP  - 723
EP  - 751
PB  - SPRINGER
CY  - DORDRECHT
ER  -