The Ulysses spacecraft has been orbiting the Sun on a highly inclined ellipse (i=79∘, perihelion distance 1.3 AU, aphelion distance 5.4 AU) since it encountered Jupiter in February 1992. Since then it has made almost three revolutions about the Sun. Here we report on the final three years of data taken by the on-board dust detector. During this time, the dust detector recorded 609 dust impacts of particles with masses 10−16g⩽m⩽10−7g, bringing the mission total to 6719 dust data sets. The impact rate varied from a low value of 0.3 per day at high ecliptic latitudes to 1.5 per day in the inner solar system. The impact direction of the majority of impacts between 2005 and 2007 is compatible with particles of interstellar origin; the rest are most likely interplanetary particles. We compare the interstellar dust measurements from 2005/2006 with the data obtained during earlier periods (1993/1994) and (1999/2000) when Ulysses was traversing the same spatial region at southern ecliptic latitudes but the solar cycle was at a different phase. During these three intervals the impact rate of interstellar grains varied by more than a factor of two. Furthermore, in the two earlier periods the grain impact direction was in agreement with the flow direction of the interstellar helium while in 2005/2006 we observed a shift in the approach direction of the grains by approximately 30∘ away from the ecliptic plane. The reason for this shift remains unclear but may be connected with the configuration of the interplanetary magnetic field during solar maximum. We also find that the dust measurements are in agreement with the interplanetary flux model of Staubach et al. (1997) which was developed to fit a 5-year span of Ulysses data.

The Galileo spacecraft was the first man-made satellite of Jupiter, orbiting the planet between December 1995 and September 2003. The spacecraft was equipped with a highly sensitive dust detector that monitored the jovian dust environment between approximately 2 and 370 RJ (jovian radius RJ=71 492 km). The Galileo dust detector was a twin of the one flying on board the Ulysses spacecraft. This is the tenth in a series of papers dedicated to presenting Galileo and Ulysses dust data. Here we present data from the Galileo dust instrument for the period January 2000 to September 2003 until Galileo was destroyed in a planned impact with Jupiter. The previous Galileo dust data set contains data of 2883 particles detected during Galileo's interplanetary cruise and 12 978 particles detected in the jovian system between 1996 and 1999. In this paper we report on the data of additional 5389 particles measured between 2000 and the end of the mission in 2003. The majority of the 21 250 particles for which the full set of measured impact parameters (impact time, impact direction, charge rise times, charge amplitudes, etc.) was transmitted to Earth were tiny grains (about 10 nm in radius), most of them originating from Jupiter's innermost Galilean moon Io. They were detected throughout the jovian system and the impact rates frequently exceeded 10 min−1. Surprisingly large impact rates up to 100 min−1 occurred in August/September 2000 when Galileo was far away (≈280RJ) from Jupiter, implying dust ejection rates in excess of 100 kg s−1. This peak in dust emission appears to coincide with strong changes in the release of neutral gas from the Io torus. Strong variability in the Io dust flux was measured on timescales of days to weeks, indicating large variations in the dust release from Io or the Io torus or both on such short timescales. Galileo has detected a large number of bigger micron-sized particles mostly in the region between the Galilean moons. A surprisingly large number of such bigger grains was measured in March 2003 within a four-day interval when Galileo was outside Jupiter's magnetosphere at approximately 350 RJ jovicentric distance. Two passages of Jupiter's gossamer rings in 2002 and 2003 provided the first actual comparison of in-situ dust data from a planetary ring with the results inferred from inverting optical images. Strong electronics degradation of the dust instrument due to the harsh radiation environment of Jupiter led to increased calibration uncertainties of the dust data.

This data set contains the data from the Ulysses dust detector system (UDDS) from start of mission through the end of mission, 1990-2007. (As the dust detector was turned off after Nov. 30, 2007, this is the last date for which UDDS data is recorded.) Included are the dust impact data, noise data, laboratory calibration data, and location and orientation of the spacecraft and instrument.

The dust detector system on board the Galileo spacecraft recorded dust impacts in circumjovian space during the craft's orbital mission about Jupiter. This is the eighth in a series of papers dedicated to presenting Galileo and Ulysses dust data. We present data from the Galileo dust instrument for the period January 1997-December 1999 when the spacecraft completed 21 revolutions about Jupiter. In this time interval data were obtained as high resolution realtime science data or recorded data during 449 days (representing 41% of the entire period), or via memory readouts during the remaining times. Because the data transmission rate of the spacecraft was very low, the complete data set (i.e. all parameters measured by the instrument during impact of a dust particle) of only 3% (7625) of all particles detected could be transmitted to Earth; the other particles were only counted. Together with the data of 2883 particles detected during, Galileo's interplanetary cruise and 53 53 particles detected in the jovian system in 1996, complete data of 15 861 particles detected by the Galileo dust instrument from 1989 to 1999 are now available. The majority of the detected particles were tiny grains (about 10 nm in radius), most of them originating from Jupiter's innermost Galilean moon Io. They were detected throughout the jovian system and the highest impact rates exceeded 100 min(-1) (C21 orbit; 01 July 1999). With the new data set the times of onset, cessation and a 180 degrees shift in the impact direction of the grains measured during 19 Galileo orbits about Jupiter are well reproduced by simulated 9 nm particles charged up to a potential of +3 V, confirming earlier results obtained for only two Galileo orbits (Horanyi, M., Grun, E., Heck, A., 1997. Modeling the Galileo dust measurements at Jupiter. Geophys. Res. Lett. 24, 2175-2178). Galileo has detected a large number of bigger particles mostly in the region between the Galilean moons. The average radius of 370 of these grains measured in the 1996-1999 period is about 2 mu m (assuming spherical grains with density 1 g cm(-3)) and the size distribution rises steeply towards smaller grains. The biggest detected particles have a radius of about 10 mu m. (c) 2006 Elsevier Ltd. All rights reserved.

The Ulysses spacecraft has been orbiting the Sun on a highly inclined ellipse (i=79∘, perihelion distance 1.3AU, aphelion distance 5.4AU) since it encountered Jupiter in 1992. Between January 2000 and December 2004, the spacecraft completed almost an entire revolution about the Sun, passing through perihelion in May 2001 and aphelion in July 2004. In this five-year period the dust detector on board recorded 4415 dust impacts. We publish and analyse the complete data set of both raw and reduced data for particles with masses 10-16g⩽m⩽10-7g. Together with 1695 dust impacts recorded between launch of Ulysses and the end of 1999 published earlier (Grün, E., Baguhl, M., Divine, N., Fechtig, H., Hamilton, D.P, Hanner, M.S., Kissel, J., Lindblad, B.A., Linkert, D., Linkert, G., Mann, I., McDonnell, J.A.M., Morfill, G.E., Polanskey, C., Riemann, R., Schwehm, G.H., Siddique, N., Staubach, P., Zook, H.A., 1995a. Two years of Ulysses dust data. Planetary Space Sci. 43, 971–999, Paper III; Krüger, H., Grün, E., Landgraf, M., Baguhl, M., Dermott, S.F., Fechtig, H., Gustafson, B.A., Hamilton, D.P., Hanner, M.S., Horányi, M., Kissel, J., Lindblad, B., Linkert, D., Linkert, G., Mann, I., McDonnell, J.A.M., Morfill, G.E., Polanskey, C., Schwehm, G.H., Srama, R., Zook, H.A., 1995. Three years of Ulysses dust data: 1993 to 1995. Planetary and Space Sci. 47, 363–383, Paper V; Krüger, H., Grün, E., Landgraf, M., Dermott, S.F., Fechtig, H., Gustafson, B.A., Hamilton, D.P., Hanner, M.S., Horányi, M., Kissel, J., Lindblad, B., Linkert, D., Linkert, G., Mann, I., McDonnell, J.A.M., Morfill, G.E., Polanskey, C., Schwehm, G.H., Srama, R., Zook, H.A., 2001b. Four years of Ulysses dust data: 1996 to 1999. Planetary Space Sci. 49, 1303–1324, Paper VII), a data set of 6110 dust impacts detected with the Ulysses sensor between October 1990 and December 2004 is now available. The impact rate measured between 2000 and 2002 was relatively constant with about 0.3 impacts per day showing a maximum at 1.5 per day around ecliptic plane crossing in early-2001. The impact direction of the majority of impacts between 2000 and 2002 is compatible with particles of interstellar origin, the rest are most likely interplanetary particles. In 2003 and 2004 dust stream particles originating from the jovian system dominated the overall impact rate. Twenty-two individual dust streams were measured between November 2002 and December 2004. The observed impact rates are compared with models for interplanetary and interstellar dust. The dust measurements from the entire mission since Ulysses launch give good agreement with the interplanetary flux model of Staubach, P., Grün, E., Jehn, R., 1997. The meteoroid environment near Earth, Adv. Space Res. 19, 301–308.

In July 2004 the Cassini–Huygens mission reached the Saturnian system and started its orbital tour. A total of 75 orbits will be carried out during the primary mission until August 2008. In these four years Cassini crosses the ring plane 150 times and spends approx. 400h within Titan's orbit. The Cosmic Dust Analyser (CDA) onboard Cassini characterises the dust environment with its extended E ring and embedded moons. Here, we focus on the CDA results of the first year and we present the Dust Analyser (DA) data within Titan's orbit. This paper does investigate High Rate Detector data and dust composition measurements. The authors focus on the analysis of impact rates, which were strongly variable primarily due to changes of the spacecraft pointing. An overview is given about the ring plane crossings and the DA counter measurements. The DA dust impact rates are compared with the DA boresight configuration around all ring plane crossings between June 2004 and July 2005. Dust impacts were registered at altitudes as high as 100000km above the ring plane at distances from Saturn between 4 and 10 Saturn radii. In those regions the dust density of particles bigger than 0.5μm can reach values of 0.001m-3.

In 1992 the impact ionisation dust detector on board the Ulysses spacecraft discovered periodic burst-like streams of dust particles within 2AU from Jupiter. The streams occurred at approximately monthly intervals (28 ± 3 days) and the maximum impact rates exceeded, by three orders of magnitude, the rates typically measured in interplanetary space [3]. These fluctuations were a complete surprise because no periodic phenomenon for small dust particles in interplanetary space was known before. The dust streams gave a completely new picture of interplanetary dust because they showed for the first time that dust originating from the environment of a planet can reach interplanetary space. The particles arrived at Ulysses in collimated streams radiating from close to the line of sight to Jupiter, suggesting a jovian origin. The 28-day periodicity was explained by the particle interaction with the interplanetary magnetic field [4]. Derived particle sizes were ∼ 10 nm and the particle speeds exceeded 200 km s [6]. With such high speeds, the jovian system turned out to be a source for interplanetary and even interstellar dust. Later Galileo measurements showed strong particle interaction with Jupiter’s magnetosphere [5, 2] and Io was identified as the grain source [1]. 12 years after its initial Jupiter flyby Ulysses approached the planet a second time in February 2004 with a closest approach distance of 0.8 AU. The first dust stream was detected in November 2002 at a distance of 3.3 AU from Jupiter which was the most distant stream detected so far. The maximum impact rates, measured around equatorial plane crossing of Jupiter, were three times larger than in 1992 (Figure 1). At least 17 dust streams were detected by December 2004, confirming grain properties recognised during the first flyby. The measured impact directions are consistent with a grain origin from the jovian system. The streams occur at about 26 day intervals closely matching the solar rotation period. Close to the equatorial plane the streams occur at a 13 day period, in agreement with theoretical predictions [4]. The impact direction of the streams is correlated with the polarity and strength of the interplanetary magnetic field. Taken all dust stream measurements since 1992 collected with three spacecraft together (Ulysses, Galileo, Cassini) the streams were detected over a large latitude range from the equator to the polar regions of Jupiter (−35◦ to +75◦ jovigraphic latitude).

The Galileo spacecraft was launched in 1989, and—between 1995 and 2003—was the first spacecraft in orbit about Jupiter. The in-situ dust instrument on board was a highly sensitive impact-ionisation dust detector which measured the speed, mass and impact direction of dust particles hitting a metal target. It provided a unique 12-year record of cosmic dust in interplanetary and circumjovian space. Degradation of the instrument electronics caused by the harsh radiation environment in the inner jovian magnetosphere was recognised in various ways: the sensitivity for dust detection dropped by a factor of 7.5 between 1996 and 2003 while the noise sensitivity decreased by up to a factor of 100. Shifts in the parameters measured during dust impacts and noise events (charge amplitudes and signal rise times, etc.) required a time-dependent algorithm for noise identification. After noise removal a total of 21224 complete data sets for dust impacts (i.e. impact charges, signal rise times, impact direction, etc.) is available from the entire Galileo mission between 1989 and 2003 (18340 data sets from the Jupiter mission after 1996). This homogeneous data set has been used in many investigations of jovian dust published already or ongoing. Electronics degradation prevents the application of the mass and speed calibration to data obtained after 2000. Only in cases where the impact speed of grains is known by other means can grain masses be derived for later measurements. The drop of the detection sensitivity also required a time-dependent correction for fluxes of jovian dust streams, reaching a factor of 20 in 2002. We use the derived homogeneous noise-removed data set for long-term monitoring of the jovian dust streams with Galileo. The derived fluxes of dust stream particles were highly variable by about five orders of magnitude, between 3×10-3 and 6×102m-2s-1 and exhibited strong orbit-to-orbit variability. This extensive and valuable data set is available for further detailed investigations.

A Dust Telescope is a combination of a Trajectory Sensor with an analyzer for the elemental composition of micrometeoroids or space debris. Dust particle trajectories are determined by the measurement of the electric signals that are induced when a charged grain passes through a position sensitive electrode system. The position sensitive system consists of four planes of wires where each wire is connected to a separate charge sensitive amplifier. The amplifier is based on CMOS technology and was developed in cooperation with the ASIC Laboratory in Heidelberg. Furthermore, a 32 channel transient recorder (TR) running with 20 MHz and 10 bit resolution was developed and manufactured in order to store the individual signals. This system allows the accurate determination of the particle velocity vector. The elemental composition of particles is analyzed by a time-of-flight system for the ions which are generated upon the particle impact. The large area of this mass analyzer is 0.1 m(2) and has a mass resolution above 100 for all possible impact locations. This paper describes the performances of the laboratory model of the Trajectory Sensor and shows the study results of the mass spectrometer.

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 field on the trajectories of dust particles as well as fragmentation of particles due to electrostatic disruption.

The Ulysses spacecraft is orbiting the Sun on a highly inclined ellipse (i=79°, perihelion distance 1.3 AU, aphelion distance 5.4 AU). Between January 1996 and December 1999 the spacecraft was beyond 3 AU from the Sun and crossed the ecliptic plane at aphelion in May 1998. In this 4-yr period 218 dust impacts were recorded with the dust detector on board. We publish and analyse the complete data set of both raw and reduced data for particles with masses 10−16–10−8g. Together with 1477 dust impacts recorded between launch of Ulysses and the end of 1995 published earlier (Grün et al., Planet. Space Sci. 43 (1995a) 971; Krüger et al., Planet. Space Sci. 47 (1999b) 363), a data set of 1695 dust impacts detected with the Ulysses sensor between October 1990 and December 1999 is now available. The impact rate measured between 1996 and 1999 was relatively constant with about 0.2 impacts per day. The impact direction of the majority of the impacts is compatible with particles of interstellar origin, the rest are most likely interplanetary particles. The observed impact rate is compared with a model for the flux of interstellar dust particles. The flux of particles several micrometres in size is compared with the measurements of the dust instruments on board Pioneer 10 and Pioneer 11 beyond 3 AU (Humes, J. Geophys. Res. 85 (1980) 5841). Between 3 and 5 AU, Pioneer results predict that Ulysses should have seen 5 times more (∼10μm sized) particles than actually detected.

The dust detector system onboard Galileo has recoding dust impacts in circumjovian space since the spacecraft was injected into a bound orbit about Jupiter in December 1995. This is the sixth in a series of papers dedicated to presenting Galileo and Ulysses dust data. We present data from the Galileo dust instrument for the period January to December 1996 when the spacecraft completed four orbits about Jupiter (G1, G2, C3 and E4). Data were obtained as high-resolution realtime science data or recorded data during a time period of 100 days, or via memory read-outs during the remaining times. Because the data transmission rate of the spacecraft is very low, the complete data set (i.e. all parameters measured by the instrument during impact of a dust particle) for only 2% (5353) of all particles detected could be transmitted to Earth; the other particles were only counted. Together with the data for 2883 particles detected during Galileo's interplanetary cruise and published earlier, complete data of 8236 particles detected by the Galileo dust instrument from 1989 to 1996 are now available. The majority of particles detected are tiny grains (about 10nm in radius) originating from Jupiter's innermost Galilean moon Io. These grains have been detected throughout the Jovian system and the highest impact rates exceeded 100min−1. A small number of grains has been detected in the close vicinity of the Galilean moons Europa, Ganymede and Callisto which belong to impact-generated dust clouds formed by (mostly submicrometer sized) ejecta from the surfaces of the moons (Krüger et al., 1999e. Nature 399, 558). Impacts of submicrometer to micrometer sized grains have been detected throughout the Jovian system and especially in the region between the Galilean moons.

The Ulysses spacecraft is orbiting the Sun on a highly inclined ellipse (i = 79°). After its Jupiter flyby in 1992 at a heliocentric distance of 5.4 AU, the spacecraftreapproached the inner solar system, flew over the Suns south polar region in September 1994,crossed the ecliptic plane at a distance of 1.3 AU in March 1995, and flew over the Suns northpolar region in July 1995. We report on dust impact data obtained with the dust detector onboardUlysses between January 1993 and December 1995. We publish and analyse the complete dataset of 509 recorded impacts of dust particles with masses between 10−16 g–10−7 g. Together with 968 dust impacts from launch until the end of 1992 published earlier (Grün et al., 1995c), information about 1477 particles detected with theUlysses sensor between October 1990 and December 1995 is now available. The impact ratemeasured between 1993 and 1995 stayed relatively constant at about 0.4 impacts per day andvaried by less than a factor of ten. Most of the impacts recorded outside about 3.5 AU arecompatible with particles of interstellar origin. Two populations of interplanetary particles havebeen recognized: big micrometer-sized particles close to the ecliptic plane and smallsub-micrometer-sized particles at high ecliptic latitudes. The observed impact rate is comparedwith a model for the flux of interstellar dust particles which gives relatively good agreement withthe observed impact rate. No change in the instruments noise characteristics or degradation of thechanneltron could be revealed during the three-year period.

Dust measurements have been obtained with the dust detector onboard the Galileo spacecraft inside a distance of about 60RJ from Jupiter (Jupiter radius, RJ = 71,492 km) during two periods of about 8 days around Galileo's closest approaches to Ganymede on 27 June and on 6 Sept 1996. The impact rate of submicrometer‐sized particles fluctuated by a factor of several hundred with a period of about 10 hours, implying that their trajectories are strongly affected by the interaction with the Jovian magnetic field. Concentrations of small dust impacts were detected at the times of Ganymede closest approaches that could be secondary ejecta particles generated upon impact of other particles onto Ganymede's surface. Micrometer‐sized dust particles, which could be on bound orbits about Jupiter, are concentrated in the inner Jovian system inside about 20RJ from Jupiter.

Identical in situ dust detectors are flown on board the Galileo and Ulysses spacecraft. They record impacts of micrometeoroids in the ecliptic plane at heliocentric distances from 0.7 to 5.4 AU and in a plane almost perpendicular to the ecliptic from -79 deg to +79 deg ecliptic latitude. The combination of both Ulysses and Galileo measurements yields information about the radial and latitudinal distributions of micron- and sub-micron-sized dust in the Solar System. Two types of dust particles were found to dominate the dust flux in interplanetary space. Interplanetary micrometeoroids covering a wide mass range from 10^-16 to 10^-6 g are recorded mostly inside 3 AU and at latitudes below 30 deg. Interstellar grains with masses between 10^-14 and 10^-12 g have been positively identified outside 3 AU near the ecliptic plane and outside 1.8 AU at high ecliptic latitudes (>50 deg). Interstellar grains move on hyperbolic trajectories through the planetary system and constitute the dominant dust flux (1.5 x 10^-4 m^-2 sec^-1) in the outer Solar System and at high ecliptic latitudes. To compare and analyze the Galileo and Ulysses data sets, a new model is developed based on J. Geophys. Res. 98, 17029-17048, Divine's (1993, ``five populations of interplanetary meteoroids'' model. Both models describe the interplanetary meteoroid environment in terms of dust populations on distinct orbits. Taking into account the measured velocities and the effect of radiation pressure on small particles (described by the ratio of radiation pressure force to gravity, beta), we define four populations of meteoroids on elliptical orbits and one population on hyperbolic orbit that can fit the micrometeoroid flux observed by Galileo and Ulysses. Micrometeoroids with masses greater than 10^-10 g and negligible radiation pressure (beta = 0) orbit the Sun on low to moderately eccentric orbits and with low inclinations (<=30 deg). Populations of smaller particles with mean masses of 10^-11 g (beta = 0.3), 10^-13 g (beta = 0.8), and 5 x 10^-15 g (beta = 0.3), respectively, have components with high eccentricities and have increasingly wider inclination distributions with decreasing mass. Similarities among the orbit distributions of the small particle populations on bound orbits suggest that all are genetically related and are part of an overall micrometeoroid complex that prevails in the inner Solar System. The high-eccentricity component of the small particle populations may actually be beta-meteoroids which are not well characterized by our measurements. Our modeling suggests further that the interstellar dust flux is not reduced at Ulysses' perihelion distance (1.3 AU) and that it contributes about 30% of the total dust flux observed there. (Less)