"The search for life on Mars, a search on two planets" Abstract: The search for life on Mars is a journey involving high resolution analysis of meteorites on earth and highly capable robotic packages sent to the surface of Mars. The lecture will review how these two approaches are revealing new insights into the search for life elsewhere and the origin of life on earth. [mehr]

The Flybys of Comets Tempel 1 and Hartley 2 Abstract: The flybys of comets T1 and H2, while short-lived, provide new insights and questions about cometary formation and evolution. The major results from the imager and IR spectrometer will be discussed, with particular emphasis on compositional inferences. [mehr]

Using oxygen isotopes in planetary sciences [mehr]

Titan’s chaotic upper atmosphere Abstract: Saturn’s largest moon Titan has been observed systematically since the arrival of Cassini/Huygens in 2004. While the landing of the Huygens probe in January 2005 provided amongst other a continuous, yet single vertical profile of atmospheric properties from the thermosphere down to the surface, regular in-situ observations by the Cassini orbiter’s Ion Neutral Mass Spectrometer (INMS) above 950 km provided information on global and time variations in Titan’s thermosphere. Infrared remote sensing onboard Cassini provided further details on Titan’s stratosphere and troposphere, while UV occultations measured the mesosphere and lower thermosphere.   After 10 years of regular observations, Titan has proven to possess one of the most enigmatic atmospheres explored to-date. Density variations observed in the thermosphere show dramatic variations by orders of magnitude between observations and temperatures can vary by 100 K from one flyby to another - rates which are difficult to interpret physically. Equally, horizontal structures are counter-intuitive, suggesting a slightly hotter dayside than nightside on Titan. Work over the past years has attempted and largely failed to systematically correlate these atmosphere structures with changing conditions in Saturn’s magnetosphere, another potential energy source.  Most recently, our work has explored the potential influence of vertical coupling in the atmosphere, of Titan’s lower atmosphere driving changes above. By coupling the Titan WRF stratosphere model with our Titan Thermosphere General Circulation Model, we have found small and short term variations in the stratosphere to drive considerable variability in the thermosphere as well, remarkably consistent with observations. Our findings highlight the broader principle of processes which play a secondary role in atmospheres of bodies closer to the Sun becoming primary in nature in atmospheres further out in the solar system where solar heating is no longer a dominant thermal energy source. [mehr]

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Atmospheric gravity waves are basic features of all planetary atmospheres. But what is their importance? In Earth's atmosphere they are primarily generated by various meteorological processes, propagate upward, produce substantial dynamical and thermal effects and variability in the mesosphere and thermosphere, and thus vertically couple the lower and upper atmosphere. Similar gravity wave processes are increasingly encountered in other planetary atmospheres. In this seminar, I will introduce how small-scale gravity waves are represented in global models and present a snapshot of recent progress in modeling their effects, specifically, in Earth and Martian atmospheres. Gravity wave processes in the context of NASA’s MAVEN mission are discussed. [mehr]

The AIDA mission will be the first space experiment to demonstrate asteroid impact hazard mitigation by using a kinetic impactor to deflect an asteroid. It consists of ESA's orbiter AIM which will orbit the binary asteroid Didymos in 2022, and NASA's DART projectile scheduled for impact on the secondary in October 2022, while Didymos is at its closest approach to Earth. Both AIM and ground based telescopes will measure the change of orbit of the secondary. AIDA will return vital data to determine the momentum transfer efficiency of the kinetic impact and measure key physical properties of the target asteroid. Additionally, a lander and a full suite of instruments will give us the first tomographic map of an asteroid interior. [mehr]

The Dawn spacecraft has visited asteroid Vesta and is now in orbit around dwarf planet Ceres. Its data revealed quite individual bodies despite similar size and similar location in the solar system. These “minor planets” are new milestones on the way to a revised view onto the planets: Classification as “planets”, “comets”, “satellites” becomes more misleading than describing. A comparative view on the former “asteroids” Vesta and Ceres will demonstrate this. [mehr]

Introduction: The impact cratering shaped Moon’s landscapes offer a fossil record of the Near Earth Object populations. This record goes back to the formation and cooling of the lunar crust [1-3] when the crust was sufficiently viscous to retain the cratering “scars”. The crater densities of highland and mare surfaces testify a substantially higher impact flux rate during the first ~1.5 Ga compared to that for the last 3 Ga of our Solar System. The temporal evolution of the impact flux (i.e., the bombardment timeline) is the topic of intense scientific debate for at least the past 40 years. The end-member interpretations are 1) the “Early Heavy Bombardment” (EHB) that assumes an exponentially declining impact flux rate until it oscillated around a much lower value during the last 3 Ga, and 2) the “Late Heavy Bombardment” (LHB) referring to a brief “terminal lunar cataclysm” with a sharply rising and falling peak centered around 3.9 Ga ago [1,2]. On current state of concepts: While the EHB may still be considered the least assumptions model consistent with our fuzzy sample-based knowledge of the bombardment timeline, it lacks a proper physical (orbital) explanation. In light of the recent knowledge from lunar, terrestrial and asteroid belt samples, the classical LHB scenario is no longer attractive [1,2]. In addition, it appears highly inconsistent with orbital models [4-5]. This particularly stems from the difficulty or even impossibility to properly correlate the Apollo and Luna samples to their bedrock or crater ejecta source. However, present re-interpretation of old data together with acquisition of new data from Apollo and Luna samples suggest that intermediate views that consider a complex bombardment timeline with moments of heavy bombardment are a better venue to consensus. Two events able to initiate moments of heavy bombardment are: 1) The giant Moon forming impact event created an extremely massive heliocentric debris disk; meaning a new projectile population with high impact probability onto the Earth and the Moon for the following few hundred million years [6-7]. 2) The reorganization of the planetary system architecture as proposed by the updated “Nice”-model basically explains the extended tail-end of the heavy bombardment as testified by the crater density on mare basalts and possibly the Archean spherule layers on Earth [4]. However the level of resolution in dynamical models is not yet equal to data from samples. 3) Other impactor populations (planetary left overs, comets, debris discs, asteroid belts) that resulted from single events or dynamical processes leading to additional spikes in the impact flux cannot be excluded. One should be aware that “you don’t know what you don’t know”. Therefore, additional work on current samples and/or new samples is required. Acknowledgments: All this work has been carried out in collaboration with Jörg Fritz and Stephanie Werner. References: [1] Fernandes V. A. et al. 2013. MaPS 48:241–269. [2] Fritz J. et al. 2014. PSS 98:254–267. [3] Werner S.C. et al. 2002. Icarus 156:287-290. [4] Werner, S.C. 2014. EPSL 400:54–65. [5] Morbidelli A. et al. 2012. EPSL 355:144–151. [6] Schlichting H. et al. 2012. Astroph. J. 8:8. [7] Jackson A.P. and Wyatt M. 2012. Month. N. R. Astron. Soc. 425:657–679. [mehr]

Assumptions on the early evolution of the Asteroid Vesta include a combined (i) ordinary plus carbonaceous chondritic bulk composition, (ii) complete melting of the silicate fraction within tens of Ma after CAI, (iii) equilibration of silicate material and FeNiS-core, as well as (iv) formation of an ultramafic (peridotitic/pyroxenetic) lower crust and upper mantle plus a basaltic crust. There is, however, little consensus about the volume proportions within the silicate components. Estimates of the thickness of the basaltic crust depend on crystallization models of the bulk silicate composition. The diogenitic component of DAG 779 (believed to originate from Vesta) reveals temperatures of orthopyroxene (opx) formation from 1450 and 1200 °C measured for bulk exsolved opx and for host regions between exolution lamellae , respectively. This range coincides with calculated temperatures of opx formation by equilibrium and fractional crystallization sequences for Vestas silicate shell. Calculations of the thickness of the remaining basaltic (eucritic) crust and the onset of the ultramafic interior suggest depths of 20 to 40 km. The early large impacts that produced the Veneneia and Reasilvia basins most probably excavated rocks from this depth but did not produce large amounts of olivine-rich rocks on Vestas surface. In the light of the above mentioned crystallization models, an orthopyroxenite-rich layer can be assumed to depth of up to 80 km; olivine-dominated rocks are probably restricted to Vestas deeper mantle. [mehr]

Icy moons of giant planets are now known to have liquid water oceans beneath their icy mantles. Deep radio probing is the only chance to get immediate proof of that now. In the presented talk, issues of deep radio probing of icy moons are addressed. Previously developed theoretical background of Martian GPR exploration is reviewed. A new type instrument concept -- a passive radio wave sounder -- is introduced. Utilization of Jovian natural radio emissions as a sounding wave allows to create a low mass and weight radio instrument exceeding active radars in sounding capabilities. Comparative analysis of both active and passive instrument types and simulation results supporting feasibility of the new instrument are presented. [mehr]

Recent surface processes on Mars are dominated by aeolian and ice-related activity controlled by seasonal atmospheric cycles. For the Martian past, it has become widely accepted that cyclic changes in the planet's orbital configuration has been causing changes on much larger temporal and regional scales leading to re-distribution of polar ices and deposition of ice-rich so-called mantling deposits. While some observational evidence indeed points towards links between extensive mid-latitude glaciation and climate cycles on Mars, questions related to the origin of ice remain unanswered. In this talk, some of these links based on geomorphic observations are discussed. [mehr]

Meteorites are often used as ground truth for celestial bodies for which we have no samples. For the Moon the link between lunar samples and their origin has been proven. Among the achondrites, HED meteorites are one of the most abundant population. The hypothesis that HED meteorites have originated from Vesta has generally been accepted. However, recently this assumption has been questioned in the literature. Because of the relevance of this hypothesis for the analysis of remote sensed data from Vesta, we review the pros and cons of the ongoing debate in the scientific community. [mehr]

Energetic Neutral Atoms (ENAs) result from Charge Exchange (CE) interactions between energetic, singly charged particles and cold neutral gases that co-exist in a plasma environment. Although the Ion and Neutral Camera (INCA), as part of the Magnetospheric Imaging Instrument (MIMI) suite on board Cassini, is designed to perform ENA measurements originating from the vicinity of Saturn (the Cassini s/c is in orbit around Saturn since 2004), imaging of the Heliosphere (in Hydrogen ENAs) lies well within the instrument capabilities. After 11 years of imaging the heliosphere with INCA, the ENA observations together with the Voyager-LECP in-situ measurements (in overlapping energy bands), have already revolutionized our notions about the formation and interactions of the global heliosphere, providing insights on the plasma processes at ~100 AU that were substantially at variance with previous theories and models. Although the question of how the HS responds to the variability of solar wind conditions and in what manner this response is connected to solar activity through the solar cycle has been addressed partly through modeling, the true manifestation of the HS (moreover in a global scale) to the solar activity have not been directly measured to date. Assessing any proposed interpretation of the HS requires the evaluation of the physical properties of the underlying source proton population in the broad context of the solar wind. Our current analysis on yearly averaged all sky ENA maps over the time period 2003-2014, show that ENA intensities decrease during the declining phase of SC23 by ~x3 from 2003 to 2011 but recover through 2014 (SC24). Similarly, V1,2 ion intensities also decrease and then recover through 2014. The similarity of time profiles of remotely sensed ENA and locally measured ions show that (a) ENA originate in the HS, and (b) the global HS responds promptly (within ~1-1.5 years) to outward-propagating solar wind changes throughout the SC. Further, recovery of the HS during SC24 proceeds asymmetrically from south to north in the general direction of the nose, which may be related to the non-symmetric evolution of solar coronal holes during SC recovery. [mehr]

Here, we present a study of ionospheric convection at high latitudes that is based on satellite measurements of the Electron Drift Instrument (EDI) on-board the Cluster satellites, which were obtained over a full solar cycle (2001-2014). The mapped drift measurements are covering both hemispheres and a variety of different solar wind and interplanetary magnetic field (IMF) conditions. The large amount of data allows us to perform more detailed statistical studies. We show that flow patterns and polar cap potentials can differ between the two hemispheres on statistical average for a given IMF orientation. In particular, during southward directed IMF conditions, and thus enhanced energy input from the solar wind, we find that the southern polar cap has a higher cross polar cap potential. We also find persistent north-south asymmetries which cannot be explained by external drivers alone. Much of these asymmetries can probably be explained by significant differences in the strength and configuration of the geomagnetic field between the Northern and Southern Hemisphere. Since the ionosphere is magnetically connected to the magnetosphere, this difference will also be reflected in the magnetosphere in the form of different feedback from the two hemispheres. Consequently, local ionospheric conditions and the geomagnetic field configuration are important for north-south asymmetries in large regions of the geospace. The average convection is higher during periods with high solar activity. Although local ionospheric conditions may play a role, we mainly attribute this to higher geomagnetic activity due to enhanced solar wind - magnetosphere interactions. [mehr]

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Forty-five years after they were launched, the two deep space probes of the Voyager Interstellar Mission are now exploring the distant nose region of the heliosphere in two different directions at distances from ~85 to ~135 astronomical units from the sun. Voyager 1 (V1) measurements of the magnetic field, plasma waves and energetic particles, have revealed numerous surprises, forcing a rethinking of our concepts of the heliosphere and its interaction with the local interstellar medium. Most heliospheric researchers now believe that V1 entered interstellar space in late August 2012 and are constructing models based on this assumption. However, we find, using pressure balance and measurements of the low energy neutral hydrogen atoms spectrum, that the strength of the magnetic field that VI is currently observing is only half of the strength of the local interstellar field. This and other observational evidence leads us to conclude that Voyager 1 is not yet in interstellar space but rather remains in a most unusual region of the heliosheath. [mehr]

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Since August 2014, the OSIRIS cameras provided the first detailed images of the bilobate nucleus of 67P/Churyumov-Gerasimenko comet, and the extremely variegated geomorphology of its surface became immediately clear. Most of the morphological features have been subsequently attributed to evolving processes dominated by sublimation and thermal fatigue. Erosional processes have indeed shaped the nucleus exposing terraces, persistent steep cliffs and continuous and parallel linear features. Hence, the resulting morphology appears to be structurally controlled by a primary stratification. A 3D geological model, constrained by strata attitudes and equipotential surfaces of the gravity fields of the two lobes considered separately, can easily explain complex surface morphologies such as cuestas, mesas, series of stair-case terraces and persistent cliffs and provides important clues on the nucleus interior structure confirming that its bilobate shape is most probably the result of a gentle merging of two independent objects characterized by a primordial onion-like inner structure. This geological interpretation would have far-reaching consequences on how comets may have formed and evolved. [mehr]

Mit 11 erfolgreich gestarteten Satelliten ist die TU Berlin unter den Universitäten mit eigenen Satelliten weltweit führend. 7 Satelliten der TUBSAT-Familie und 4 Cubesats wurden bereits gebaut. Weitere 6 Nanosatelliten sind gegenwärtig in der Entwicklung. 2017 startet der Nanosatellit Technosat als Technologie-Demonstrator. Satelliten sind Bestandteil des Forschungsprogramms des Fachgebiets Raumfahrttechnik, das sich in 4 Schwerpunkte gliedern lässt: 1. Miniaturisierung von Raumfahrtkomponenten, wie Reaktionsräder, Sender und Empfänger, Navigationstechnik, sowie Erforschung neuer Technologien wie fluiddynamische Aktuatoren und multifunktionale Komponentenintegration, 2. Miniaturisierung von ganzen Raumfahrtsystemen wie Satelliten, Rover, Höhenforschungsraketen und Bodenstationen, 3. Verteilte Raumfahrtsysteme wie Satelliten-Konstellationen, -Formationen und -Schwärme sowie modulare fraktionierte Satelliten, 4. Anwendung von Raumfahrtsystemen, wie Fernerkundungs-Datenfusion, Data Mining, weltraumgestützte Frühwarnsysteme und "Capacity building" für die Erdfernerkundung. Der Vortag stellt die Aktivitäten und Ergebnisse des Fachgebietes auf den genannten Forschungsfeldern vor sowie die enge Verbindung zwischen Forschung, Lehre und Praxis in der studentischen Ausbildung. [mehr]

The oxygen isotopic ratio ¹⁸O/¹⁶O has been measured in cometary gas for a wide variety of comets, but it has only been measured in cometary dust by Stardust. Most such measurements find a value of the ratio that is consistent with Vienna Standard Mean Ocean Water within errors. In this talk I will present the result of a measurement of the oxygen isotopic ratio in dust from Comet 67P/Churyumov-Gerasimenko with the COSIMA instrument aboard the Rosetta spacecraft. Measuring the ¹⁸O/¹⁶O ratio with COSIMA is challenging for a number of reasons, but it is possible with a reasonable degree of precision. [mehr]

This presentation will be providing an overview on laboratory experiments conducted at the TU Braunschweig with the aim to study comet activity and planet formation. First, an overview on recent competing comet formation scenarios is given, followed by with a discussion on how laboratory experiments can help to understand the different formation processes better. The second half of this talk will be focusing on the question of how laboratory works can be utilized to help interpreting observational data, for example gathered by the Rosetta spacecraft, to learn about comet activity. This presentation will be ending with an outlook on planned experiments and with an invitation to discuss the importance of future laboratory experiments with the audience. [mehr]

Cometary dust activity is usually explained by a gas drag force which lifts micrometer-sized dust particles from the nucleus' surface against the weak nucleus gravity. However, taking into account the additional cohesion forces among the dust grains then this idea becomes questionable. We present the status of a thermophysical model of dust activity and compare it with observations of the Rosetta mission to comet 67P/Churyumov-Gerasimenko. [mehr]

The interior structure of small Asteroids is assumed to be a loose rubble pile composite. How these voids are distributed, and what size scale this porosity has, is not yet known, as in-situ measurements are still outstanding. We propose a low budget, mission to scan an NEA utilizing a swarm configuration of 2 6U-Cubesats of just 13.0 kg in full flight configuration. The 200m depth penetration 20Mhz radar will allow to analyze the surface and interior structure using inverse tomography method. [mehr]

From the angular positions of the glory features observed on the upper cloud deck of Venus in three VMC channels (at 0.365, 0.513, and 0.965 mkm), the dominating sizes of cloud particles and their refractive index have been retrieved, and their spatial (in latitude) and temporal (in local time) variations have been analyzed. For this, the phase profiles of brightness were compared to the singe-scattering phase functions of particles of different sizes. [mehr]

MASCOT is a small asteroid lander launched on December 3rd, 2014, aboard the Japanese Hayabusa2 asteroid sample-return mission towards the 980 m diameter C-type near-Earth asteroid (NEA) 162173 Ryugu. The lander was jointly developed by the German Aerospace Centre (DLR) and the Centre National d'Etudes Spatiales (CNES). It is equipped with a sensor suite consisting of four fully-fledged instruments: a spectrometer (MicrOmega, IAS Paris), a camera (CAM, DLR Berlin), a radiometer (MARA, DLR Berlin) and a magnetometer (MAG, TU Braunschweig) to investigate Ryugu's surface structure, mineralogical composition, physical properties, thermal behavior and magnetic effects. The MASCOT lander has a total weight of only ~10kg and a size of 30 cm x 30 cm x 20 cm, comparable to a shoebox. Next to the 4 science payloads it accommodates all subsystems to guarantee the survival during the four years cold cruise phase and an on-surface operation and data uplink of up to 2 asteroid days. Upon arrival in Summer 2018 at the target, Hayabusa2 will map NEA Ryugu for several months before it will release MASCOT at an altitude of approx. 100m to free fall on the asteroid's surface. Since MASCOT has no attitude control, it will reach the surface and undergo a certain bouncing phase before it will finally come to rest. A mobility system allows the lander to upright into the correct measurement attitude and to relocate across the asteroids surface after the completion of its first science cycle. The system design, science instruments, and operational concept of MASCOT will be presented, with sidenotes on the development of the mission and its integration with Hayabusa2. [mehr]

Abstract: On 2016 July 3, when comet 67P was already at 3.32 AU from the sun outbound from perihelion, several instruments on board Rosetta witnessed a small outburst of activity from a point on the surface emerging from the night's shadow. The dust plume above the surface was observed by OSIRIS and Alice, and the ejected material was detected in situ by COSIMA, GIADA, ROSINA, and the Startracker camera. This talk presents a summary and synthesis of the measurements, and discusses their implications for the properties of the ejected material and the process leading to this event. [mehr]

In the scientific community, the focus of space research and model development is on understanding the underlying physics and system science of the environment in question. This often leads to a good understanding of the system, while at the same time the models in question are incapable of predicting or modeling any actual state of the system with any accuracy. Using current, state-of the art diffusion codes for the Earth’s radiation belt I will argue that our main limitation no longer lies in the models themselves but rather in the specification of their boundary conditions and other required inputs. I will further argue that in Space Weather modeling and prediction we are neither committing sufficient resources to providing these inputs, nor are we performing the required research that can effectively provide these inputs for either now-casting or forecasting needs into the future. [mehr]

This presentation will be providing an overview on laboratory experiments conducted at the TU Braunschweig with the aim to study comet activity and planet formation. First, an overview on recent competing comet formation scenarios is given, followed by with a discussion on how laboratory experiments can help to understand the different formation processes better. The second half of this talk will be focusing on the question of how laboratory works can be utilized to help interpreting observational data, for example gathered by the Rosetta spacecraft, to learn about comet activity. This presentation will be ending with an outlook on planned experiments and with an invitation to discuss the importance of future laboratory experiments with the audience. [mehr]

Chlorine and hydrogen isotope ratios of lunar materials are different from all other solar system materials measured to date. The isotopic constraints place conditions on the formation and volatility of the Moon. [mehr]

Georg Herdrich is head of the Plasma Wind Tunnels and Electric Propulsion department of the Institute of Space Systems (IRS) at the university of Stuttgart. The department is specialized on electric propulsion systems, plasma measurement systems and test benches for reentry simulations as well as test branches for Interial electrostatic confinement devices for small electron and ion jets. In his talk he will give an overview of the IRS activities, with a focus on the experimental and numerical work on MHD effects in weakly ionized plasmas, which i.a. present on the lunar surface. [mehr]

Polarimetry is routinely used as a diagnostic tool to characterize surfaces of solar system bodies, and polarization measurements of starlight reflected by exoplanets are becoming a powerful tool to study atmospheres and surfaces of other worlds. If extra-terrestial life has similar signatures as life as we know, then astronomical observations of planet Earth represent a prime benchmark case to probe biomarkers on other planets. In fact, linear polarization spectra of Earthshine (the sunlight that has been first reflected by Earth and then reflected back to Earth by the Moon) allows us to detect the presence of oxygen, ozone, and clouds in the atmosphere of our planet. Surface properties such as fractional contributions of continents and ocean, as well as vegetated areas can be inferred. Earthshine observations provide strong observational constraints on model predictions for Earth-type exoplanets. In this talk, we will compare observed polarization spectra with detailed simulations of Earthshine based on atmosphere models, and will discuss their applications to the search for life indicators in exoplanets. [mehr]

A numerical solution of the problem of light scattering by particles and particulate media becomes difficult if the particle size is much larger than the wavelength of the incident light. Accurate methods require huge hardware resources in this case. However, one can apply the geometric optics (GO) approximation. I will discuss such a GO model, its application and the prospectives of the rigorous wave-optics modelling. [mehr]

Darwin first postulated - 145 years ago - that life might have originated in “…some warm little pond with all sorts of ammonia and phosphoric salts, light, heat, electricity, etc. present, that a protein compound was chemically formed, ready to undergo still more complex changes…”. However, the 1970’s discovery of deep sea black smokers and their rich vent fauna, together with evidence from the mitochondrial tree of life, led to the currently prevailing view that life got started at deep sea vents. But it turns out that the energy required for polymerisation of organic molecules from simple amino acids comes from expelling a water molecule. In addition, the cytoplasm of cells from all three branches of life have K+/Na+ ratios more aligned with fresh water than seawater, and that certain key elements (B, Zn, Mn) required as catalysts for polymerisation are hard to concentrate in the uniform marine reservoir. Thus, it turns out that the oceans, or any permanently wet environment, are not suitable for prebiotic chemistry and thus a land-based environment undergoing wet-dry cycles is required for an Origin of Life setting. But what kind of environment? Previous authors have suggested a desert with seasonal rain, or a river flowing over komatiitic crust as possible sites for the Origin of Life. But these cold-water environments lack the capacity for compositional complexity and highly reactive interfaces. Recent discoveries from an ancient analogue site in Western Australia’s Pilbara region provide support for an Origin of Life in terrestrial hot springs. The 3.48 Ga Dresser Formation is well known as hosting some of Earth’s oldest convincing evidence of life (stromatolites, fractionated stable isotopes, and putative microbial remains), all within an active volcanic caldera characterised by voluminous hydrothermal fluid circulation. Previously, the depositional environment was considered as shallow marine, but the recent discovery of geyserite and other siliceous sinter deposits containing biosignatures and spatially closely associated with stromatolites, point to a thriving terrestrial hot spring setting with wet-dry cycles. A parallel, key, discovery is of concentrations of the critical elements required for prebiotic chemistry (B, Zn, and Mn), which arise from hot water-rock interactions. These discoveries are leading to a developing model for the Origin of Life in terrestrial hot spring fields, and have implications for Astrobiology and the search for life elsewhere in the Solar System. On Mars, we advocate for the Columbia Hills site that has known hotspring deposits identified from a previous rover mission. Further afield, advocates for exploration of the icy water moons of Saturn and Jupiter face the problem of a permanently wet environment that appears not to be favourable for life to develop. [mehr]

One of the major and unfortunately unforeseen sources of background for the current generation of X-ray telescopes, in particular the ESA X-ray satellite XMM-Newton, is due to soft (few tens-hundreds of keV) protons concentrated by the X-ray mirrors. The observing time lost is 40% in the case of XMM, affecting all the major broad science goals of this observatory, ranging from cosmology to astrophysics of neutron stars and black holes. The soft proton background can impact dramatically future large X-ray missions such as the ESA planned Athena mission. We will review the still poor understanding of the physical process at work and the connection with the magnetospheric population and acceleration sites originating the phenomenon. [mehr]

The evolutionary diversification of complex animal life on the planet earth was greatly supported by the wide-spread adoption of various biomineralising strategies. The so called ‘Cambrian Explosion’ (543 million years ago) records this rapid diversification of biomineralised forms in the fossil record. Study of the genetic and molecular biomineralising tools employed by various extant animal lineages can therefore provide a better understanding of how complex animal life first diversified. [mehr]

A fundamental property that a planet can have is if it is encompassed by radiation belts of highly energetic electrons and ions approaching light speed. The radiation belts of Jupiter and Saturn differ from Earth’s Van Allen belts not only in their extent and intensity but also in the physical processes governing them. We will explain the physics of giant planet radiation belts based on data from space missions as Juno and Cassini, and show examples of recent and ongoing studies. [mehr]

The double focusing mass spectrometer (DFMS) of theROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis)instrument on board Rosetta has enabled the discovery of a zoo ofneutral constituents in the coma of comet 67P/Churyumov-Gerasimenko.This talk will focus on halogen-bearing species in the coma andaddress their abundances, variability and isotopic composition. [mehr]

The cometary activity of 67P/Churyumov-Gerasimenko (67P/CG) during the Rosetta pre-landing phase is investigated using data from GIADA’s dust instrument subsystems (the Grain Detector System (GDS) and the Impact Sensor (IS) subsystems) and from the VIRTIS instrument on Rosetta. VIRTIS data are used to infer the photometric behavior of spectral parameters describing the spectrum of 67P/CG, and variations of this behavior among the four comet macro-regions (i.e. head, neck, body, bottom) and with local time. Our results based on GIDA data show a good correlation between the fluffy and compact particles, indicating that the source of the two different types of dust particles is likely the same. This correlation is not maintained in the coma, where fluffy and compact distributions are different. A correlation is also found between number of particles detected by GIADA and the spectral shift of the 3.2 mm band observed by VIRTIS in each comet region observed during the considered period, corroborating that the band center shift with temperature is likely due to the diurnal pre-perihelion cometary activity. We explain the used methods and discuss the found results. [mehr]

Comets, asteroids and Kuiper Belt objects are left overs of building material for our earth and the other planets in our solar system. At the time of their formation these objects, called planetesimals, built up from icy and dusty grains. In our current paradigm of solar system formation it was turbulent flows and metastable flow patterns like zonal flows and vortices that concentrated mm to cm sized pebbles. What was missing until recently was a physically motivated prediction on the typical sizes at which planetesimals should form via this process. With the lastest series of simulations we were able to obtain values for the turbulent particle diffusion as a function of the particle load in the gas. Thus, we can predicts the initial size of planetesimals as result of a competition between gravitational concentration and turbulent diffusion. Based on these findings we develop a recipe to introduce planetesimal formation into population synthesis models for Exo-Planets. [mehr]

Beyond the 8 planets around the sun more than 3000 planets have been found around other stars. One of them is in orbit around Proxima Centauri at a distance of just 4 light years, others are as far as thousands of light years away. Let's have a look at how these so-called exoplanets have been detected, how their physical and orbital properties compare to the architecture of the solar system, and what kind of discoveries we can expect during our lifetimes. [mehr]