TY - JOUR A1 - Krüger, Harald A1 - Krivov, Alexander V. A1 - Grün, Eberhard T1 - A dust cloud around Ganymede Maintained by hypervelocity impacts of interplanetary micrometeoroids Y1 - 2000 SN - 0032-0633 ER - TY - JOUR A1 - Thiessenhusen, Kai-Uwe A1 - Krivov, Alexander V. A1 - Krüger, Harald A1 - Grün, Eberhard T1 - A dust cloud around Pluto and Charon Y1 - 2002 SN - 0032-0633 ER - TY - JOUR A1 - Krivov, Alexander V. A1 - Krüger, Harald A1 - Grün, Eberhard A1 - Thiessenhusen, Kai-Uwe A1 - Hamilton, Douglas P. T1 - A tenuous dust ring of Jupiter formed by escaping ejecta from the Galilean satellites Y1 - 2002 SN - 0148-0227 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 - Postberg, Frank A1 - Grün, Eberhard A1 - Horanyi, Mihaly A1 - Kempf, Sascha A1 - Krueger, Harald A1 - Schmidt, Jürgen A1 - Spahn, Frank A1 - Srama, Ralf A1 - Sternovsky, Zoltan A1 - Trieloff, Mario T1 - Compositional mapping of planetary moons by mass spectrometry of dust ejecta JF - Planetary and space science N2 - Classical methods to analyze the surface composition of atmosphereless planetary objects from an orbiter are IR and gamma ray spectroscopy and neutron backscatter measurements. The idea to analyze surface properties with an in-situ instrument has been proposed by Johnson et al. (1998). There, it was suggested to analyze Europa's thin atmosphere with an ion and neutral gas spectrometer. Since the atmospheric components are released by sputtering of the moon's surface, they provide a link to surface composition. Here we present an improved, complementary method to analyze rocky or icy dust particles as samples of planetary objects from which they were ejected. Such particles, generated by the ambient meteoroid bombardment that erodes the surface, are naturally present on all atmosphereless moons and planets. The planetary bodies are enshrouded in clouds of ballistic dust particles, which are characteristic samples of their surfaces. In situ mass spectroscopic analysis of these dust particles impacting onto a detector of an orbiting spacecraft reveals their composition. Recent instrumental developments and tests allow the chemical characterization of ice and dust particles encountered at speeds as low as 1 km/s and an accurate reconstruction of their trajectories. Depending on the sampling altitude, a dust trajectory sensor can trace back the origin of each analyzed grain with about 10 km accuracy at the surface. Since the detection rates are of the order of thousand per orbit, a spatially resolved mapping of the surface composition can be achieved. Certain bodies (e.g., Europa) with particularly dense dust clouds, could provide impact statistics that allow for compositional mapping even on single flybys. Dust impact velocities are in general sufficiently high at orbiters about planetary objects with a radius > 1000 km and with only a thin or no atmosphere. In this work we focus on the scientific benefit of a dust spectrometer on a spacecraft orbiting Earth's Moon as well as Jupiter's Galilean satellites. This 'dust spectrometer' approach provides key chemical and isotopic constraints for varying provinces or geological formations on the surfaces, leading to better understanding of the body's geological evolution. KW - Moon KW - Europa KW - Ganymede KW - Dust KW - Surface composition KW - Spectrometry Y1 - 2011 U6 - https://doi.org/10.1016/j.pss.2011.05.001 SN - 0032-0633 VL - 59 IS - 14 SP - 1815 EP - 1825 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Grün, Eberhard A1 - Krivov, Alexander V. T1 - Dust astronomy : new venues in interplanetary and interstellar dust research Y1 - 2002 SN - 1-58381-113-3 ER - TY - JOUR A1 - Kirvov, Alexander V. A1 - Wardinski, Ingo A1 - Spahn, Frank A1 - Krüger, Harald A1 - Grün, Eberhard T1 - Dust on the outskirts of the Jovian System Y1 - 2002 UR - http://www.idealibrary.com/links/doi/10.1006/icar.2002.6848 ER - TY - JOUR A1 - Thiessenhusen, Kai-Uwe A1 - Colwell, Josh E. A1 - Srama, Ralf A1 - Grün, Eberhard A1 - Spahn, Frank T1 - Dynamics of dust ejected from enceladus : application to the cassini dust detector Y1 - 1999 ER - TY - JOUR A1 - Thiessenhusen, Kai-Uwe A1 - Krueger, Harald A1 - Spahn, Frank A1 - Grün, Eberhard T1 - Large dust grains around Jupiter : the observations of the Galileo dust detector Y1 - 2000 ER - TY - JOUR A1 - Kempf, Sascha A1 - Srama, Ralf A1 - Grün, Eberhard A1 - Mocker, Anna A1 - Postberg, Frank A1 - Hillier, Jon K. A1 - Horanyi, Mihaly A1 - Sternovsky, Zoltan A1 - Abel, Bernd A1 - Beinsen, Alexander A1 - Thissen, Roland A1 - Schmidt, Jürgen A1 - Spahn, Frank A1 - Altobelli, Nicolas T1 - Linear high resolution dust mass spectrometer for a mission to the Galilean satellites JF - Planetary and space science N2 - The discovery of volcanic activity on Enceladus stands out amongst the long list of findings by the Cassini mission to Saturn. In particular the compositional analysis of Enceladus ice particles by Cassini's Cosmic Dust Analyser (CDA) (Srama et al., 2004) has proven to be a powerful technique for obtaining information about processes below the moon's ice crust. Small amounts of sodium salts embedded in the particles' ice matrices provide direct evidence for a subsurface liquid water reservoir, which is, or has been, in contact with the moon's rocky core (Postberg et al., 2009, 2011b). Jupiter's Galilean satellites Ganymede, Europa, and Callisto are also believed to have subsurface oceans and are therefore prime targets for future NASA and ESA outer Solar System missions. The Galilean moons are engulfed in tenuous dust clouds consisting of tiny pieces of the moons' surfaces (Kruger et al., 1999), released by hypervelocity impacts of micrometeoroids, which steadily bombard the surfaces of the moons. In situ chemical analysis of these grains by a high resolution dust spectrometer will provide spatially resolved mapping of the surface composition of Europa. Ganymede, and Callisto, meeting key scientific objectives of the planned missions. However, novel high-resolution reflectron-type dust mass spectrometers (Sternovsky et al., 2007; Srama et al., 2007) developed for dust astronomy missions (Gran et al., 2009) are probably not robust enough to be operated in the energetic radiation environment of the inner Jovian system. In contrast, CDA's linear spectrometer is much less affected by harsh radiation conditions because its ion detector is not directly facing out into space. The instrument has been continuously operated on Cassini for 11 years. In this paper we investigate the possibility of operating a CDA-like instrument as a high resolution impact mass spectrometer. We show that such an instrument is capable of reliably identifying traces of organic and inorganic materials in the ice matrix of ejecta expected to be generated from the surfaces of the Galilean moons. These measurements are complementary, and in some cases superior, compared to other traditional techniques such as infrared remote sensing or in situ ion or neutral mass spectrometers. KW - Europa KW - Ganymede KW - Callisto KW - Surface composition KW - Mass spectroscopy KW - Dust Y1 - 2012 U6 - https://doi.org/10.1016/j.pss.2011.12.019 SN - 0032-0633 VL - 65 IS - 1 SP - 10 EP - 20 PB - Elsevier CY - Oxford ER -