The Surface Dust Analyser (SUDA) is a dust impact mass spectrometer onboard of the Europa Clipper mission for investigating the surface composition of the Galilean moon Europa. The instrument is a Time--Of--Flight (TOF) impact mass spectrometer derived from previously flown dust compositional analyzers on Giotto, Stardust, and Cassini. SUDA uses the technology of the successful Cosmic Dust Analyzer (CDA) operating on Cassini and employs advanced reflectron-type ion optics for increased mass resolution. The instrument will measure the mass, speed, charge, elemental and isotopic composition of impacting grains. Atmosphereless planetary moons such as the Galilean satellites are wrapped into a ballistic dust exosphere populated by tiny samples from the moon's surface produced by impacts of fast micrometeoroids. SUDA will measure the composition of such surface ejecta during close flybys at Europa to obtain key chemical constraints for revealing the satellite's composition, history, and geological evolution. Because of their ballistic orbits, detected ejecta can be traced back to the surface with a spatial resolution roughly equal to the instantaneous altitude of the spacecraft.SUDA will detect a wide variety of compounds from Europa's surface over a concentration range of percent to ppm and connect them to their origin on the surface. This allows simultaneous compositional mapping of many organic and inorganic components, including both major and trace compounds, with a single instrument. Any recent tectonic activity, cryovolcanism, or resurfacing event is detectable by variations in the surface composition. This can be linked to corresponding geological features, including the analysis of compositional variations across large craters on Europa. SUDA will further the understanding of Europa's surface couples to its interior source regions.In this presentation, we will discuss SUDA's unique capabilities to collect compositional ground truth from orbit and how SUDA contributes to the Europa Clipper science goals.

Due to the their ubiquity and the high impact energy leading to extremely high temperatures and pressures in the affected materials, the physical processes caused by HVIs play an important role in a variety of fields such as the investigation of matter at extreme pressures and temperature, shock waves in solid bodies or even Solar System research, planetology, cosmic dust research and space engineering:Cratering phenomena throughout the Solar System :The first systematic investigation of HVIs of micro-meteoroites was dedicated to the understanding of micro-cratering on lunar rock samples. The size and morphology of resulting micro-craters was investigated as a function of particle size and impact speed. Planetology – Characterization, development and calibration of dust sensors measuring the composition, size and trajectory information of micrometeoroids aboard interplanetary spacecrafts. Astrobiology – Simulation of hyper-velocity impacts of organic micron-sized projectiles and mass spectrometric analysis of impact plasmas containing complex organic molecules; simulation of micrometeoroid impacts onto water ice surfaces. Space weathering: Alteration of bombarded surfaces Cosmic Dust research: A major part of what we know today of HVIs of micro-meteoroites was obtained in the process of developing, calibrating and operation of in situ instruments for the investigation of dust in the Solar System. Thereby induced physical processes generate measurable signals which are then transmitted to Earth and can be analyzed afterwards.There are a variety of methods for in situ dust measurements such as the detection of thin foil penetration, the particle charge, the emerging impact flash or ions generated upon impact, revealing the particles’ velocity, trajectory, mass and even chemical composition. Of all these methods, the generation of charge during impacts provides one of the most sensitive methods for the detection and and the most comprehensible characterization of dust particles in space. The characterization of the dynamical and even chemical properties of dust particles in the Solar System allows us to investigate the origin of cosmic dust and its role in the formation of the Solar System and even its role in the origin of life. Impact physics/Materials under extreme conditions – Investigation of plasma and material conditions of projectile-surface interactions under hyper-velocity impact conditions. Electrostatic dust accelerators To calibrate in-situ dust instruments and to get a deeper understanding of the processes involved, hypervelocity impact measurements under similar and well defined conditions are required. For this purpose, a Van-de-Graaff type ion accelerator was modified at the MPI-K/HD in the late 1960ies. The accelerator was equipped with a dust source capable of charging and accelerating dust particles (Fig. 1).The accelerator covers a large portion of the speed and size ranges needed for most cosmic applications with velocities between 1 to about 80 km s−1 (Fig. 2).After being located for over 5 decades at the MPI-K, the dust accelerator has been moved to the IRS/UniS. This relocation gives us the opportunity to optimize the set up and the also the whole dust research laboratory in its entirety.Particle properties and beam monitoringThe dust beam originates from the dust source within the high voltage terminal of the accelerator.(Fig.1). After exiting the source, the dust particles are accelerated in the electrostatic field towards the experimental set-up. Before reaching the experiment chamber, the particles are registered, characterized, and eventually selected while passing the beam line detectors of the Particle Selection Unit (PSU). For this, the particles are been detected by a chain of detectors measuring the particle's primary surface charge using an induction tube and a charge-sensitive amplifier (CSA). The PSU determines the grain speed and mass in order to select individual dust grains on the basis of a speed and mass window given by the experimentator. Cosmological relevant materials Dust Materials: For the above described method of acceleration to work, the particles must therefore be capable of carrying charge and hence the range of materials used has been restricted to those which are either wholly conductive or those with a conductive coating. In the last few years two techniques of coating underwent significant improvements, opening up a whole new range of material types to investigate.Target Materials: Due to the bean geometry and the vacuum conditions , there are a variety of constraints fr the target mounting and properties. Solid metal and silicate target, of terrestrial and meteoritic origin, can be easily used and have been investigated numerous times in the past. Experiments with icy targets are planned for the near future. Investigation of impact ionization with A linear TOF mass spectrometerThe characteristics of the impact plasma, such as the velocity distribution of the ions and the ion appearance in the mass spectra, can be analyzed with a linear TOF mass spectrometer. Here, the combination of velocity and angular distributions of the ions results in a broadening of the mass lines, determining their shapes. To study the distribution of the ion velocities alone, we developed an optimized narrow aperture mass spectrometer (Fig.3). The simple set up and the almost homogenous fields allow to calculate the flight times due to the known response function of the instrument. The measured mass line profile can be inverted for the distribution of initial velocity and subsequently the initial kinetic energies of the ions as shown in Fig.4.In addition to TOF other important measurements will address: cratering, secondary ejecta, neutral production, optical spectroscopy of the of the impact flash, and the characterization of the EM waves.The combination of future theoretical studies of the impact processes and the subsequent expansion of the impact produce plasma with this expanded set of measurements will be a powerful tool to investigate the state of the hot compressed matter.

The Ulysses spacecraft was launched in 1990 and, after a Jupiter swing-by in 1992, became the first interplanetary spacecraft orbiting the Sun on a highly inclined trajectory with an inclination of 79 ∘ . The spacecraft was equipped with an impact ionization dust detector which provided 17 years of in situ dust measurements in interplanetary space from 1990 to 2007. Cometary meteoroid streams (also referred to as trails) exist along the orbits of comets, forming fine structures of the interplanetary dust cloud. We use the Interplanetary Meteoroid Environment for eXploration (IMEX) dust streams in space model (Soja RH et al . 2015 Characteristics of the dust trail of 67P/Churyumov-Gerasimenko: an application of the IMEX model. Astron. Astrophys. 583 , A18. (doi: 10.1051/0004-6361/201526184 )) to predict cometary stream traverses by Ulysses and re-analyse the Ulysses dust dataset in order to identify impacts of cometary stream particles detected during such trail traverses. We identify 19 particles compatible with three Ulysses trail traverses on 12 March 1995, 25–27 April 2001 and 16–19 May 2001. The particle origin is compatible with up to five comets, i.e. 10P/Tempel 2, 146P/Shoemaker-LINEAR, 267P/LONEOS and possibly 45P/Honda-Mrkos-Pajdušáková and P/1999 RO28 (LONEOS). We find a dust spatial density in these trails of approximately 2 − 7 ⋅ 10 − 8 m − 3 . The radii of the detected cometary stream particles derived from the dust instrument calibration are in the micrometre range. The in situ analysis of meteoroid trail particles in space, which can be traced back to their source bodies, opens a new opportunity for remote compositional analysis of comets and asteroids without the necessity to send a spacecraft to or even land on these celestial bodies, opening new opportunities for future space missions equipped with in situ dust analyzers. This article is part of the theme issue 'Dust in the Solar System and beyond'.

Cometary meteoroid streams (also referred to as trails) exist along the orbits of comets, forming fine structures of the interplanetary dust cloud. The streams consist predominantly of the largest cometary particles (with sizes of approximately (100 micrometer to 1 cm) which are ejected at low speeds and remain very close to the comet orbit for several revolutions around the Sun. The Interplanetary Meteoroid Environment for eXploration (IMEX) dust streams in space model (Soja et al., Astronomy & Astrophysics, 2015) is a universal model that simulates recently created cometary dust streams in the inner solar system, developed under ESA contract. IMEX is a physical model for dust dynamics and follows the orbital evolution of the streams of 420 comets. Particles are emitted when the comet is in the inner solar system, taking into account comet apparitions between the years 1700 and 2080. The dust ejection is described by an emission model, dust production rate and mass distribution covering the mass range from 10^-8 kg to 10^-2 kg (approximately corresponding to 100 micrometer to 1 cm particles). The dust production is calculated from the comet's absolute magnitude, the observed water production rate and dust-to-gas ratio. For each emitted particle, the trajectory is integrated individually including solar gravity, planetary perturbations as well as solar radiation pressure and Poynting-Robertson drag. The model calculates dust number density, flux and velocity. We apply the IMEX model to study comet stream traverses by the Ulysses spacecraft. Ulysses was launched in 1990 and, after a Jupiter swing-by in 1992, became the first interplanetary spacecraft orbiting the Sun on a highly inclined trajectory with an inclination of 80 degrees. The spacecraft was equipped with an impact ionization dust detector which provided the longest data set of continuous in situ dust measurements in interplanetary space existing to date, covering 17 years from 1990 to 2007. In addition to the interplanetary dust complex, several dust populations were investigated with the Ulysses dust instrument in the past: interstellar dust sweeping through our solar system, streams of approximately 10 nanometer-sized dust particles emanating from Jupiter's volcanically active moon Io, as well as sub-micrometer-sized particles driven away from the Sun by solar radiation pressure (so-called beta particles). Here we study the detection conditions for cometary meteoroid streams with the dust detector on board the Ulysses spacecraft and present first results from our attempt to identify cometary stream particles in the measured dust data set. Acknowledgements: The IMEX Dust Streams in Space model was developed under ESA funding (contract 4000106316/12/NL/AF - IMEX).

The Cosmic Dust Analyzer (CDA) onboard Cassini characterized successfully the dust environment at Saturn from 2004 to 2017. The study of Saturn’s E ring and its interaction with the embedded moons was a major scientific goal of Cassini. After the end of the mission, the entire CDA data can be analyzed to derive the global parameters of Saturn’s E ring.The CDA instrument measured the primary charge, speed, mass and composition of individual submicron and micron sized dust grains. The instrument was continuously collecting data of dust fluxes and apparent dust densities. Therefore the data cover radial distances between 3 and 20 Saturn radii and equatorial as well as high latitudes. However, the relative impact velocities varied with the dynamical properties of the Cassini spacecraft and with the dust particles. Small relative impact speeds lead to higher mass thresholds for impact detection such that this effect has to be considered in calculating apparent dust densities. Furthermore, the pointing profile of the instrument and the related observation geometry was highly variable. This paper describes an approach to define a dust environment model at Saturn based on the entire CDA dataset.

Interplanetary and interstellar dust as windows into solar system origins and evolution.1We can explore in situ the building blocks of the planets by measuring the trajectories and compositions of thousands of dust particles from comets and our interstellar neighborhood, a f e f d .

Cometary meteoroid trails exist in the vicinity of comets, forming fine structure of the interplanetary dust cloud. The trails consist predominantly of cometary particles with sizes of approximately 0.1 mm to 1 cm which are ejected at low speeds and remain very close to the comet orbit for several revolutions around the Sun. When re-analysing the Helios dust data measured in the 1970s, Altobelli et al. (2006) recognized a clustering of seven impacts, detected in a very narrow region of space at a true anomaly angle of 135 deg, which the authors considered as potential cometary trail particles. We re-analyse these candidate cometary trail particles to investigate the possibility that some or all of them indeed originate from cometary trails and we constrain their source comets. The Interplanetary Meteoroid Environment for eXploration (IMEX) dust streams in space model is a new universal model for cometary meteoroid streams in the inner solar system, developed by Soja et al. (2015). Using IMEX we study cometary trail traverses by Helios. During ten revolutions around the Sun, and in the narrow region of space where Helios detected the candidate dust particles, the spacecraft repeatedly traversed the trails of comets 45P/Honda-Mrkos-Pajduvsakova and 72P/Denning-Fujikawa. Based on the detection times and particle impact directions, four detected particles are compatible with an origin from these two comets. We find a dust spatial density in these trails of about 10^-8 to 10^-7 m^-3. The in-situ detection and analysis of meteoroid trail particles which can be traced back to their source bodies by spacecraft-based dust analysers opens a new window to remote compositional analysis of comets and asteroids without the necessity to fly a spacecraft to or even land on those celestial bodies. This provides new science opportunities for future missions like Destiny+, Europa Clipper and IMAP.

Context. The interplanetary dust complex is currently understood to be largely the result of dust production from Jupiter-family comets, with contributions also from longer-period comets (Halley- and Oort-type) and collisionally produced asteroidal dust. Aims. Here we develop a dynamical model of the interplanetary dust cloud from these source populations in order to develop a risk and hazard assessment tool for interplanetary meteoroids in the inner solar system. Methods. The long-duration (1 Myr) integrations of dust grains from Jupiter-family and Halley-type comets and main belt asteroids were used to generate simulated distributions that were compared to COBE infrared data, meteor data, and the diameter distribution of lunar microcraters. This allowed the constraint of various model parameters. Results. We present here the first attempt at generating a model that can simultaneously describe these sets of observations. Extended collisional lifetimes are found to be necessary for larger (radius ≥ 150 μ m) particles. The observations are best fit with a differential size distribution that is steep (slope = 5) for radii ≥ 150 μ m, and shallower (slope = 2) for smaller particles. At the Earth the model results in ~ 90–98% Jupiter-family comet meteoroids, and small contributions from asteroidal and Halley-type comet particles. In COBE data we find an approximately 80% contribution from Jupiter-family comet meteoroids and 20% from asteroidal particles. The resulting flux at the Earth is mostly within a factor of about two to three of published measurements.

The orbital distributions of dust particles in interplanetary space are inferred from several meteoroid data sets under the constraints imposed by the orbital evolution of the particles due to the planetary gravity and Poynting-Robertson effect. Infrared observations of the zodiacal cloud by the COBE DIRBE instrument, flux measurements by the dust detectors on board Galileo and Ulysses spacecraft, and the crater size distributions on lunar rock samples retrieved by the Apollo missions are fused into a single model. Within the model, the orbital distributions are expanded into a sum of contributions due to a number of known sources, including the asteroid belt with the emphasis on the prominent families Themis, Koronis, Eos and Veritas, as well as comets on Jupiter-encountering orbits. An attempt to incorporate the meteor orbit database acquired by the AMOR radar is also discussed.

In the early 1990s, contemporary interstellar dust penetrating deep into the heliosphere was identified with the in-situ dust detector on board the Ulysses spacecraft. Later on, interstellar dust was also identified in the data sets measured with dust instruments on board Galileo, Cassini and Helios. Ulysses monitored the interstellar dust stream at high ecliptic latitudes for about 16 years. The three other spacecraft data sets were obtained in the ecliptic plane and cover much shorter time intervals.We compare in-situ interstellar dust measurements obtained with these four spacecrafts, published in the literature, with predictions of a state-of-the-art model for the dynamics of interstellar dust in the inner solar system (Interplanetary Meteoroid environment for EXploration, IMEX), in order to test the reliability of the model predictions. Micrometer and sub-micrometer sized dust particles are subject to solar gravity and radiation pressure as well as to the Lorentz force on a charged dust particle moving through the Interplanetary Magnetic Field. The IMEX model was calibrated with the Ulysses interstellar dust measurements and includes these relevant forces. We study the time-resolved flux and mass distribution of interstellar dust in the solar system. The IMEX model agrees with the spacecraft measurements within a factor of 2 to 3, also for time intervals and spatial regions not covered by the original model calibration with the Ulysses data set. It usually underestimates the dust fluxes measured by the space missions which were not used for the model calibration, i.e. Galileo, Cassini and Helios. IMEX is a unique time-dependent model for the prediction of interstellar dust fluxes and mass distributions for the inner and outer solar system. The model is suited to study dust detection conditions for past and future space missions.

The JAXA/ISAS spacecraft DESTINY+ will be launched to the active asteroid (3200) Phaethon in 2022. Among the proposed core payload is the DESTINY+ Dust Analyzer (DDA) which is an upgrade of the Cosmic Dust Analyzer flown on the Cassini spacecraft to Saturn (Srama et al., 2011). We use two up-to-date computer models, the ESA Interplanetary Meteoroid Engineering Model (IMEM, Dikarev et al., 2005a, c), and the interstellar dust module of the Interplanetary Meteoroid environment for EXploration model (IMEX;Sterken et al. 2013; Strub et al., 2019) to study the detection conditions and fluences of interplanetary and interstellar dust with DDA. Our results show that a statistically significant number of interplanetary and interstellar dust particles will be detectable with DDA during the 4-years interplanetary cruise of DESTINY+. The particle impact direction and speed can be used to descriminate between interstellar and interplanetary particles and likely also to distinguish between cometary and asteroidal particles.

The Martian Moons Exploration (MMX) spacecraft is a JAXA mission candidate to Mars and its moons Phobos and Deimos. MMX will be equipped with the Circum-Martian Dust Monitor (CMDM) which is a newly developed light-weight (650 g) large area (∼ 1 m) dust impact detector. We use the Interplanetary Meteoroid Environment for eXploration model (IMEX; [5, 6]) to study the detectability of cometary meteoroid trails by CMDM. Given its large detection area and high sensitivity CMDM will likely be capable to in-situ detect cometary meteoroid trails for the first time.

The application of impact ionization for the measurement of micrometeoroids in space is a sensitive and established method for particles in the size range between a few nanometers and a few micrometers. For the measurement of micrometeoroid trajectories, the knowledge of the velocity vector and the related impact position is required. A typical impact ionization detector employs a hemispherically shaped conductive metal target, and a hemispherical grid electrode. The impact charge is dependent on the particle mass, particle speed and incident angle. For a collimated particle flux which is parallel to the symmetry axis, the impact direction and its related impact angle relative to the target normal varies with the radial distance from the symmetry axis. It is therefore essential to consider the impact position during calibration of impact ionization detectors. Furthermore, the induced charge signal shape varies with impact position. We perform simulations with the Coulomb software package and we do compare the results with experimental data. An empirical formula is derived to determine the impact location of the particle from the target and grid induction signals.

Electrostatic dust transport has been hypothesized to explain a number of observations of unusual planetary phenomena. Here, it is demonstrated using three recently developed experiments in which dust particles are exposed to thermal plasma with beam electrons, beam electrons only, or ultraviolet (UV) radiation only. The UV light source has a narrow bandwidth in wavelength centered at 172 nm. The beam electrons with the energy of 120 eV are created with a negatively biased hot filament. When the vacuum chamber is filled with the argon gas, a thermal plasma is created in addition to the electron beam. Insulating dust particles of a few tens of microns in diameter are used in the experiments. Dust particles are recorded to be lofted to a height up to a few centimeters with a launch speed up to 1 m/s. These experiments demonstrate that photo and/or secondary electron emission from a dusty surface changes the charging mechanism of dust particles. According to the recently developed "patched charge model", the emitted electrons can be re-absorbed inside microcavities between neighboring dust particles below the surface, causing the accumulation of enhanced negative charges on the surrounding dust particles. The repulsive forces between these negatively charged particles may be large enough to mobilize and lift them off the surface. These experiments present the advanced understanding of dust charging and transport on dusty surfaces, and laid a foundation for future investigations of its role in the surface evolution of airless planetary bodies.

Charged dust particles in space can be detected by in situ sensors using charge induction. Such trajectory sensors are normally based on many grid or wire electrodes connected to individual charge sensitive amplifiers. In this article we describe a new approach to measure the trajectory of a charged dust particle by a single charge sensitive amplifier. The signal shape is used to calculate particle speed, mass and trajectory. The detector employs two half-circular grid electrodes, and the electrodes are connected to the differential input stage of an amplifier. Simulations using the Coulomb 9.0 software package were performed in order to determine the expected signal shapes depending on the particle parameters (entry location and incident angles). The simulated charge signals show, that the chosen measurement concept is an efficient method for low-power and low-mass dust trajectory sensors.

The charge state of dust particles on regolith surfaces exposed to ultraviolet radiation or plasma is investigated for understanding the role of electrostatic dust transport in the surface evolution of airless planetary bodies. Our charge measurement shows that the regolith dust that can be electrostatically transported or lofted carries large negative charges. This result is consistent with our patched charge model, which predicts that dust particles forming microcavities in the regolith surfaces can attain large negative charges by collecting photoelectrons and/or secondary electrons emitted from neighboring particles and the resulting repulsive forces between these negatively charged particles lead to their mobilization. The observed negative charge polarity is contrary to the generally expected positive charges on the regolith dust emitting photoelectrons. The measured negative charges are orders of magnitude larger than the prediction by classical charging models. Our laboratory measurements provide critical initial charging conditions for regolith dust dynamics studies.

On 3 July 2016, several instruments on board ESA's Rosetta spacecraft detected signs of an outburst event on comet 67P, at a heliocentric distance of 3.32 AU from the sun, outbound from perihelion. We here report on the inferred properties of the ejected dust and the surface change at the site of the outburst. The activity coincided with the local sunrise and continued over a time interval of 14 - 68 minutes. It left a 10m-sized icy patch on the surface. The ejected material comprised refractory grains of several hundred microns in size, and sub-micron-sized water ice grains. The high dust mass production rate is incompatible with the free sublimation of crystalline water ice under solar illumination as the only acceleration process. Additional energy stored near the surface must have increased the gas density. We suggest a pressurized sub-surface gas reservoir, or the crystallization of amorphous water ice as possible causes.

The COSIMA mass spectrometer on the Rosetta spacecraft has analysed the solid organic matter found in dust particles emitted by comet 67P/Churyumov–Gerasimenko; this matter is similar to the insoluble organic matter extracted from carbonaceous chondrites such as the Murchison meteorite, but is perhaps more primitive.