Enceladus, a moon of Saturn, is a prime candidate for extraterrestrial life due to its subsurface ocean and organic-rich water plumes, discovered by the Cassini mission. Exploring this potential involves significant challenges due to the harsh and dynamic environment of Enceladus. The moon’s cryogenic temperatures, tectonic activity and uncertain surface textures necessitate robust and reliable means of surface sample acquisition. This thesis introduces an ice sampling system designed for future lander missions to this moon, integrating digital holographic microscopy, microfluidics, and boundary layer pumping to meet these challenges.
The proposed system is controlled by a single rotary actuator, minimizing mechanical complexity and enhancing reliability for deep space operations. It samples, liquefies, and prepares ice for microscopic examination to detect potential microorganisms. The sample is acquired via a conical boundary layer pump and delivered into a microfluidic disk for analysis. The integrated system operates as a single static unit with closed-loop control, enabling precise management of fluid dynamics, and thereby the sample.
The integrated digital holographic microscope provides non-invasive, three-dimensional imaging capa- bilities without mechanical focusing, making it suitable for the extreme conditions on Enceladus. The proof-of-concept prototype demonstrates the system’s feasibility and effectiveness through experimental validation of all subsystems. Additionally, open-source software was developed for processing hologram images, including particle counting and blob analysis.
Future work will focus on adapting this technology for broader terrestrial scientific applications and achiev- ing the necessary technology readiness level for space missions. The system’s robust architecture pro- vides a versatile platform that facilitates the integration of not only microscopy but also a diverse array of other life detection instruments. Consequently, this sampling apparatus represents a viable and innovative solution for the detection of life on Enceladus and other icy worlds.

Saturn's icy moon, Enceladus, has captivated scientists since NASA's Cassini spacecraft discovered massive plumes of water vapour and ice erupting from its south pole. The goal of this study was to present a novel opportunity to characterise the particles in the plumes by searching for optical phenomena such as rainbows and halos in the geysers of Enceladus using Cassini's remote sensing data. During several flybys, we discovered unusual stripe-like patterns within these plumes using simultaneous observations in the Cassini VIMS (Visible and Infrared Mapping Spectrometer) and ISS (Imaging Science Subsystem). This anomaly, unlike any other known optical phenomenon, indicates the presence of an inclined, periodic, millimetre-sized structure in the Saturnian system. We propose two hypotheses for these patterns: they may be caused by a periodic structure in Saturn's Norse group orbits or the E-ring. This unexpected discovery could offer new insights into the particle dynamics within Saturn's environment.

Enceladus, one of the icy moons of Saturn, has been of major scientific interest since the Cassini-Huygens mission has explored the Saturn system. This is due to cryovolcanic geysers with complex organic molecules and other ingredients for life in it blasting into space from its subglacial warm ocean. The moon's harsh environmental conditions require innovative bio-inspired locomotion strategies that enable the exploration of Enceladus. This thesis presents a novel ice adhesion effector based on the thermoelectric effect to create reversible adhesive connections. The effector developed here has a recorded ice adhesive strength of 1.5 MPa; enough to support the small-scale robotic system developed in this thesis. The robotic system combines a tracked locomotion method with the ice adhesion technology, that enables the robot to move continuously on steep inclined ice walls. This new technology can be used for transportation of scientific instruments in extreme environments.

The James Webb Space Telescope (JWST) has observed the leading and trailing hemisphere of Jupiter's largest moon Ganymede in August 2022. The resulting spectra from the Near InfraRed Spectrograph (NIRSpec) are dominated by water ice and CO2 features. At 3.1 micron the spectra show the Fresnel reflection peak of water ice. Analysing this feature gives insight into the crystallinity of water ice on Ganymede's surface. Crystallinity is influenced by temperature, particle bombard-
ment, water vapor deposition and cryovolcanic activity. Therefore, analysing the distribution of the crystallinity of water ice on Ganymede gives inside into energetic processes occurring on the surface of the icy moon as well as the longitudinal and latitudinal variations of these processes.

This study is part of an ongoing research project, which aims to increase the physical understanding of the plume formation on Saturn’s icy moon Enceladus. The experimental setup presented in this study is the third iteration of the physical models aiming to recreate the main plume characteristics, where in this study the effects of the channel length, width, type (straight, converging/diverging or diverging), temperature and material are explored and linked to Enceladus’ crevasses. This is done by conduct- ing experiments with 7 different models, where the temperature and pressure are measured along the channels. The models are placed on top of a water-filled reservoir, where the reservoir conditions can be controlled to a limited extent by varying the heating power supplied to the reservoir water. The experimental setup is placed in the test section of the Hypersonic Test Facility Delft (HTFD), which functions as a vacuum chamber.

It is shown that the varying geometry of the channel imposes constraints on the maximum expansion angle before flow separation occurs, the sonic point location and the length/width combination in order to achieve a certain vent Mach number and mass flow rate, although this is also decided by the reservoir and ambient conditions. However, besides the physical properties of the model, there is evidence that the flow properties are dominated by the thermal processes occurring inside the setup. Condensation occurs only in the reservoir, releasing latent heat and making the isentropic flow assumption invalid by definition. It is demonstrated that it is likely that the thermal radiation from the test section of the HTFD onto the model is sufficient to thermally choke the flow. It is unlikely that the flows become choked due to the effects of friction alone. Cooling the models by 10-15°C did not result in significant changes in flow properties, and to have noticeable effects on the flow, the models would have to be cooled to much lower temperatures so that condensation occurs in the channel instead of the reservoir. Although the vapor remains unsaturated in the channels, there are signs of local temperature spikes in the ex- panding sections of the channels, near the vent, when either no or low heating power is supplied to the reservoir water and the pressure in the channel is reduced. This implies that either the temperature at the center of the channel is lower than what could be expected from the temperature measurements and heat is thus released by the deposition of the vapor, or the particles that condensed in the reser- voir partially evaporate after the throat of the channel, after which the evaporative cooling freezes the remainder of the particles, with the accompanying latent heat release. It is also not expected that a pressurized reservoir is necessary to create the plumes on Enceladus, nor is the presence of a geomet- rical throat, due to the combined effects of friction and condensing vapor. The results of one physical model are compared to a computational fluid dynamics model using the same geometry, and the main difference between the physical and numerical model is that the vent pressure of the numerical model is approximately half the vent pressure of the physical model, and the temperature of the numerical model dropped to about -50°C at the expanding section of the channel where the temperature only increased throughout the channel for the physical model. This, and the small heat spike near the vent under low-power conditions, has questioned the accuracy of the temperature measurement method and further research would be required to improve this accuracy.

A new era of exploration is on the horizon with missions such as the James Webb Space Telescope and the JUpiter Icy Moons Explorer (JUICE), focusing on the enigmatic icy moons within our solar system. Previous missions, like the Cassini-Huygens mission, have provided an invaluable wealth of data regarding Saturnian moons, shedding light on their intricate characteristics. However, despite past studies, a clear link between various surface-altering processes—such as E-ring bombardment, meteoroid impacts, photolysis, dark material, plasma, and energetic electron bombardment—and terrain features has not been fully explored.

This investigation employs the Hapke photometric model to fit the reflectance spectra of the icy moons by using a Least Squares Method algorithm. A novel validation approach is followed by utilizing experimental data obtained from crushed ice particles sourced from the Solid Spectroscopy Hosting Architecture of Databases and Expertise (SSHADE). Additionally, this data serves as a testing ground for innovative techniques in estimating crystallinity based on the 2- and 1.65-micron absorbance features of water ice.

By using data from Cassini's Visual and Infrared Mapping Spectrometer (VIMS), this thesis delves into the characteristics of the icy regolith on moons such as Rhea, Dione, and Enceladus. The analysis encompasses three studies: well-resolved terrain units, variations across an entire moon following their longitudinal lines, and a comparative examination of primary regions affected by various exogenic processes between the different moons.

The results of this study underscore the distinct impacts of each process on the icy regolith. In conclusion, by observing surface features such as grain sizes, crystallinity and surface roughness, it is possible to determine which processes are dominating on the moon's surface. Knowing how these characteristics evolve with time, such observations could also be used to determine (relative) ages of the surface's features.

Mixed ices of carbon dioxide (CO₂) and water (H₂O), prevalent in cometary nuclei, solar system satellites, and interstellar dust particles, have posed a persistent challenge in understanding the fundamental behaviors of carbon dioxide in these icy environments. Specifically, the intriguing shift in the CO₂ stretching fundamental band observed on icy moons like Europa and Ganymede has remained enigmatic. In this study, we undertake a comprehensive investigation to elucidate this phenomenon by characterizing carbon dioxide on Ganymede and Europa through temperature-dependent spectral analyses.

Laboratory experiments involve the study of pure CO₂ ice and its mixtures with water at varying concentrations, mimicking astrophysical conditions. Utilizing temperature-programmed desorption (TPD) and Fourier-transform infrared spectroscopy (FTIR) techniques, coupled with Gaussian deconvolution of obtained spectra, we explore the molecular interactions underlying the observed spectral shifts. Our experiments at 10 K under ultra-high vacuum conditions replicate interstellar medium conditions, providing crucial insights into CO₂ behavior in icy environments.

In the discussion, a detailed overview is presented of the positions and behaviors of the fitted Gaussians for the asymmetric stretching bands of CO₂ in pure form and when co-deposited with water. The temperature-dependent evolution of these bands reveals intricate dynamics, emphasizing the influence of CO₂ concentration on the shifting positions and shapes of the spectral features.

The conclusions highlight key findings, including the complex nature of CO₂ interactions within water ice, manifested in the emergence of multiple peaks at different concentrations. The thermal desorption analyses unveil distinct desorption behaviors, shedding light on the interactions during ice phase transitions. Importantly, our laboratory results align with observations from the James Webb Space Telescope (JWST), providing a synergistic approach to understanding CO₂ behavior on icy worlds. The variations observed in Ganymede’s spectra across latitudes and longitudes further corroborate the influence of temperature and UV irradiation on CO₂ dynamics within the ice.

This study contributes valuable insights into the molecular intricacies of CO₂ in mixed ices, bridging laboratory experiments with observational data. The synergy between these approaches promises a more profound understanding of CO₂ behavior in diverse astrophysical environments, advancing our knowledge of icy worlds in our Solar System and beyond.

In this study, plume experiments were conducted to mimic the thermodynamic conditions on Saturn's moon, Enceladus. The icy moon subsurface ocean and cracks in the surface have been simulated by using a liquid water reservoir and a narrow channel, while the low-pressure environment at Enceladus’ surface was achieved with a vacuum chamber. We aimed to examine how channel temperature affected the plume's behavior, testing two models with differing wall temperatures: room temperature and near 0°C. The colder model better replicated Enceladus' plumes, producing a saturated flow in which icy particles due to nucleation were seen. A conservative 1.5-3% minimum solid fraction is estimated from measurements and modeling. Pitot-tube measurements indicated Mach numbers around 1, with velocities between 400-500 m/s. Flow temperature and velocity closely correlated with wall temperature, indicating effective heat transfer. The study suggests that supersonic plume velocities observed on Enceladus can be achieved through thermal effects within the icy crust's crevasse, without requiring extreme expansion ratios. Additionally, the research provides evidence of the relationship between the crevasse's expansion ratio and the flow and wall temperatures.

Enceladus has all the ingredients to support life in its ocean and is therefore a good place to start looking for extraterrestrial life in our Solar System. To explore Enceladus, a probe is needed that autonomously navigates the extreme, icy and unknown environment. Multiple robotic systems are proposed to explore Enceladus. The concept to be optimised by this research is the Freezing Locomotion Integrated Chain Kinematics (FLICK). This concept uses a track of adhesion links that use state-of-the-art ice locomotion: By melting and freezing the ice with peltier modules integrated into the links, the robot can move over the ice wall. To reach subzero temperatures to freeze the ice, the hot side of the Peltier modules must be cooled. The aim of this research is to optimise the adhesion link design by the replacement of the water cooling system with a Phase Change Material (PCM) cooling system. Utilising the latent heat storage of the PCM, this research provides a solid-state cooling solution. The PCM container was made of aluminium to increase the heat transfer from the Peltier module to the PCM and enable the heat absorbed by the PCM to radiate to the environment. Furthermore, 3 heat fins were used to increase the contact area between the PCM and the container, increasing the available latent heat storage. The cooling performance of various PCMs was tested and the octadecane was found to be the best option, due to its high latent heat capacity and relatively low density. Tests on ice showed ice adhesion with PCM cooling of the Peltier modules was possible. A theoretical model was built to estimate the required octadecane volume to obtain subzero temperatures. 7.457 g of octadecane was integrated into the adhesion link of FLICK. The model of the new link obtained a minimum temperature of -1.1 $\deg$C and subzero cooling time of 45 s, for an ambient temperature of 21 $\deg$C without the presence of ice. Using the designed PCM cooling mechanism, the mass of FLICK's cooling system could be reduced from >1309 g to 375.68 g. However, the system must be built and tested to assess its behaviour and viability. This design assumed Earth conditions. To make the system fit to the cold temperatures and low pressures of Enceladus, the adhesion mechanism should be tested in a cooled vacuum chamber.

This Master thesis consists in investigating the formation and behavior of vapor and ice plumes. These plumes can occur in icy moons of our solar system, such as Europa or Enceladus, which are widely believed to have a liquid water ocean beneath their crust. These plumes most likely consist of a sub- surface reservoir of liquid water fed by the ocean, a crevasse, and a vent at the ice surface. Under certain conditions, the liquid water starts evaporating and, due to the high reservoir pressure, the result- ing vapour starts flowing upwards through the crevasse. Due to the high pressure difference between the reservoir and the vent at near vacuum conditions, supersonic plumes are formed. This work stud- ies the reservoir conditions and plume physics, gathering different models available in literature and comparing them to available data, such as that from observations from Cassini spacecraft. First, a model capable of describing the condensation phenomenon is sought. The effects of the consequent release of latent heat to be absorbed back by the vapour flow are also studied. Grains will then start to nucleate and grow. These particles can either collide and stick to the walls or keep flowing mixed with the vapour. Some of the above mentioned latent heat can be absorbed back by the icy walls of the crevasse and generate more vapour by sublimation. Further, this project also aims to extend the model mentioned above so that it considers the effects of a fully multi-phase, multidimensional flow, checking for the effects of rarefaction and hence the limits of the continuum assumption. Finally, a similarity analysis is performed so that the influence of working with scales as different as the channels used in the laboratory at TU Delft or the real dimensions of the crevasses found in Enceladus can be fully tackled. Any progress on the ongoing investigations about the physical characteristics of these plumes could be crucial to deepen our knowledge on geological mechanisms in icy moons of our solar system. This, in turn, could trigger research on organic compounds present in these moons, perhaps even allowing for the existence of life. Further, the model used throughout this work can be applied to study power production devices where condensation might play an important role, such as steam turbines for light-water-cooled nuclear reactors or turbines proposed to be used in innovative organic Rankine cycle (ORC) configurations, natural gas supersonic separators, supercritical CO2 compressors for large-scale carbon capture and sequestration (CCS) and micro-nozzles.

The Saturnian moon Titan has a methane-based hydrological cycle similar to the water cycle on earth. This includes lakes, fluvial drainage networks, clouds and has evidence for precipitation of methane rain. Here we explore the impact of rainfall on Titan based on an analogue laboratory approach. While the composition and structure of the Titan atmosphere and its cloud systems has been studied by the Cassini-Huygens missions, the chemical composition of rain drops remains undetermined. Recent studies have put forward the possibility of soluble nitrogen within rain drops that were earlier assumed to be purely made of methane. Based on simulations, we find a 77% - 23% distribution of methane and nitrogen. The ratio was used to develop a suitable laboratory analogue approach to study splash erosion by rain drop impacts. Using this analogue approach that involved impacting individual drops on soil sample analogues and custom-built numerical models, we find that that rain drops on Titan can redistribute soil particles at larger distances (30 - 600 mm) than Earth due to different energy transmission percentages from drop to splashed matter (15% - 50% of the drop, in comparison to water). Assuming a particle launch angle of 45◦, soil particles can reach heights of ∼10-70 mm, meaning soil splashing can create visible phenomena and proof for recent rainfall events. Such observables of Titanic rainfall can be used for more detailed surface studies by future missions, such as NASA’s Dragonfly drone.

Crater counting is the main method used to determine the age of a planetary surface. This method relies on knowing the cratering rate to estimate the absolute age of a surface. However, two theories currently exist for impact cratering of the moons in the Saturnian system, one suggesting that the majority of the impactors are of heliocentric origin (i.e. they come from orbits around the Sun), and the other suggesting that the majority of impactors are of planetocentric origin (i.e. they originate from orbits around Saturn). The different theories result in very different surface ages of the icy moons. According to the heliocentric model, the surface of Titan would date to ~3 Ga, while according to the planetocentric model the surface of Titan could be dated between ~15 Ma and ~4 Ga, allowing for much more erosion of the surface according to Bell (2020). Given that these two orbits result in different impact velocities, this work attempts to discover if the impact velocity can be determined for impactors on icy moons based on crater characteristics, such as crater depth and diameter, by recreating impacts in the lab.

Previous impact experiments have been performed with different impactors and target materials. This study aims at expanding previous research by performing tests on icy particles, something not done before. The data obtained from experiments are then used to obtain the estimated impactor diameter that created craters on the surface of these icy moons based on the expected impact velocities. This data can then be used to predict the likelihood of an impactor originating from either a heliocentric or planetocentric orbit.

This work developed several methods to produce impact craters using different instruments and different surfaces. The best results were obtained either with the gas gun and ice blocks or with the drop tower and icy particles. Using the scaling relationships found in this work, it was shown that the required impactor diameter can be obtained from craters on icy moons and that a distinction can be made between planetocentric and heliocentric impactors. However, more work is needed to narrow down the scaling relationship to obtain a reasonable impactor diameter given a certain impact crater. More information about the crater, such as the transition of ice type during an impact, should be used in the future to further constrain the velocity ranges.

Context: The Galilean moons are expected to have formed in a circumplanetary disk (CPD) and exhibit a characteristic compositional gradient: an increasing ice mass fraction with increasing distance from Jupiter. Ice released from hydrated silicates formed inside planetesimals might be the cause of this compositional gradient. One of the mechanisms known to cause significant heat in the early solar system is radiogenic heating by 26𝐴𝑙, so a different formation time for each Galilean moon could potentially explain a fully dehydrated Io, a low ice mass faction on Europa and ∼ 50% ice mass fractions on Ganymede and Callisto.
Aims: We aim to determine the mass fraction of hydrated silicates of the planetesimals in Jupiter’s CPD formed by radiogenic heating of 26𝐴𝑙 to constrain the formation times of the Galilean moons.
Methods: This is done using a numerical thermal evolution model capable of evolving planetesimals over time and altering the composition based on the internal temperature. Planetesimals are initiated with an ice mass fraction, temperature and ammonia ice concentration similar to the dust in the CPD. Their interior compositions alter by aqueous alteration, differentiation and dehydration.
Results: Hydration of rocks inside planetesimals does not occur for formation times later than 4 Myr after Ca-Al inclusion (CAI) formation, and a mass fraction of hydrous rocks of 73% is formed for 3 Myr after CAI formation. Larger planetesimals able that produce hydrated silicates dominate the compositional evolution of the population. A reduction in ammonia concentration in the ice by 50% increases the time needed to create hydrated silicates at 3 Myr after CAI formation from 1.5 Myr to > 2 Myr.
Conclusions: If Io formed before 4 Myr, it should have lost its ice no later than 1 Myr to prevent aqueous alteration. The low ice mass fraction on Europa could be explained by planetesimals formed at 3 Myr after CAI formation over a period of 1.5 Myr with a hydrous rock mass fraction of 66%, able to release 6.3% ice mass by dehydration. If the interior of Ganymede differentiated by radiogenic heating, the planetesimals should be formed before 4 Myr after CAI formation. Callisto’s partially differentiated interior requires formation times of planetesimals after 4 Myr after CAI formation.

The Cassini spacecraft, observing the Saturnian system for over 13 years, discovered aspects of the planetary system that were previously unseen. One such discovery is the eruption of geysers (plumes) from the Tiger Stripes on the surface of the icy moon Enceladus. An unexpected liquid water ocean exists underneath Enceladus’ icy crust (Postberg et al. 2018). A consequence of this finding was the complete revision of the habitability of the Solar System. This liquid ocean is propagated through conduits within the crust, and forms plumes when it reaches the surface. The plume material is believed to accelerate supersonically through nozzle-like channels (Schmidt et al. 2008) before being ejected at high speeds from the plume vents.

This thesis aims to improve the physical understanding of the interaction between the ocean, icy crust, and the plumes of Enceladus, by experimentally simulating such a plume in the wind tunnel laboratories of TU Delft, and monitoring and analyzing the dynamic physical processes taking place across the experimental setup. A physical analog, separated into regions simulating the ocean, crevasse, and vent of the plume mechanism, is monitored with pressure and temperature sensors, while plume particles are detected with optical tracing
techniques. These observations lead to estimations of the vapor mass flow rate, the outflow Mach number, and the fraction of the plume mass that is condensed. It is found that the ocean conditions can be easily controlled through an adjustable heating power supply. The vapor flow generated by the boiling ocean becomes choked in the crevasse and can attain supersonic velocities. The thermodynamic conditions at the vent of the plume exhibit a greatly varying behavior suggesting that the combined effect of the crevasse geometry and the
nucleation of vapor into liquid and icy particles results in considerable diversity in the plume characteristics. Thus, an isentropic description of the plume flow is found to be inadequate, while a Rayleigh flow is found to be feasible. Heat exchange phenomena appear to dominate locally the plume flow, as strong evidence of thermal choking in the crevasse is found. Particles with speeds of up to 426 ± 5 m/s are detected being ejected from the vent of the crevasse, and the maximum fraction of condensed plume mass is found to be 2.94% ± 0.15%. Finally, the possibility of a supersonic plume generated on Enceladus by a crevasse of constant cross-sectional area and cold walls is examined and found to be feasible.

Gas giant satellites are generally believed to form in circumplanetary disks (CPDs): a gas disk containing solid particles that accumulate to form moons over time. The discoveries by the Cassini­ Huygens mission have led to a revision of the birth environment of the Saturnian system. The aim of this thesis is to constrain the formation circumstances of Titan’s building blocks by considering the satellite’s observed characteristics, and identify the implications therefrom on Titan’s present state. We use the Protoplanetary Disk Modelling (ProDiMo) tool to model radiation thermo-­chemical CPDs, and evaluate them on their capacity to reproduce a Titan­like satellite. To form a moon with Titan’s ice-­to­-rock ratio, we find that the dust-­to-­gas ratio in the CPD must be in the order of solar nebula values, 푙표푔(푑/푔) = −2.05 ± 0.2. The ice availability upon accretion is otherwise incompatible with Titan’s moment of inertia. Our models predict a large NH3 inventory was available upon Titan’s formation, ∼10­-20wt.% of the total ice. Our findings are consistent with the hypothesis that the observed N2 in Titan is captured as NH3, and are compatible with the possible presence of a conductive layer at 45±15 km as revealed by the Huygens probe.

Comets are celestial objects that are thought to have formed at the outer edges of our solar system. The ices they contain is thought to be preserved since their formation in the molecular cloud phase, before the formation of the sun. The formation of ices in the molecular cloud occur via the ice mantle accretion rocess, by condensation of molecules onto the cold dust surfaces. Because of the very cold temperatures, the water molecules accreting onto dust are expected to form highly porous ice, as it occurs in the laboratory simulations. The icy grains encountering each other will form larger bodies, such as comets, and the porous ices plus the coagulation of icy grains leads to a fluffy cometary ice structure. This study explores the feasibility of porosity measurements by means of ultrasonicmeasurements in these ices. A new, small liquid N2 cooled vacuum chamber was used to perform the experiments with different type of ices. strophysical ices were grown on a methacrylate substrate on which an ultrasonic transducer was mounted that sent and received ultrasonic signals. Experiments with H2O (water) and CH3OH (methanol) were done by deposition from a gas phase while also H2O (water) and C2H5OH (ethanol) were frozen on top of the methacrylate from their liquid phase. These two type of experiments required an adapted version of the setup that allowed for experiments that can freeze ice from its liquid state at atmospheric pressure after which the rest of the experiment could take place in the vacuum chamber. From this experiment, the speed of sound in water ice could be determined as a function of temperature. A linear trend for a decreasing temperature in water ice was found with slope 2.5494m/(s°C) and an offset at 0°C of 3616.86m/s for a temperature range from 0°C to -100°C. Results show that propagation of ultrasonic waves in vacuum chamber-grown ice encounters too much attenuation that prevented a distinct signal to be detectable by the transducer.

Much research has been completed on Saturn's icy moon Enceladus when Cassini detected plumes in the south pole region. Studies show the south pole region has ice particles with larger grain sizes and a higher percentage of crystallinity than the rest of the moon due to these plumes. However, this trend also appears at around 30 degrees North, 90 degrees West in the northern hemisphere that is unexplainable. This thesis uses infrared spectral data from the Cassini mission and a reflectance model to identify the parameters of the surface ice from different regions on the surface to explain why the features in the northern hemisphere match that of the plume region. This study finds the grain size, porosity, roughness, formation temperature, and crystallinity of the surface ice to compare each zone. The parameters found in this study suggest that the region underwent recent resurfacing caused by activity from within the moon.

The delivery of enriched icy grains has been proposed to explain the enrichment of Jupiter with noble gases. While consideration has been given to the formation composition of the ices, the release of species as grains migrates inward toward the forming planets has not been studied extensively. The accretion and subsequent desorption of noble gas species alongside water into an enriched icy grain has been simulated with a Monte Carlo approach. Experimental measurements of desorption rates have been used to constrain the desorption rates of each noble gas species. Our results show consistency with the Galileo measurements of Jupiter. There is an indication that if the noble gases were delivered in thin ices, the Ar/Xe atmospheric signature on Neptune could be <1 rather than ~1.3 observed on Jupiter. The delivery of 0.1 to 0.5 Earth masses of enriched ice appears to be sufficient to provide the measured Jovian enrichment.

The Earth is not the only planet in the universe. It has been known for millennia that there are other planets and other bodies in the solar system. Moreover, as recent as, 1995 it has been confirmed that other stars also host planets. But how did they form? This is the main question that planet formation research has been trying to answer for at least a century. Since planet formation can not be observed directly due to instrumental limitations and limitations on human life times, this takes many generations. Each project contributing a small part to the puzzle that is planet formation. This thesis aims to address a small part of this puzzle. Planets are formed from same material as their host star. Interstellar space houses vast clouds of gas and dust. Under the influence of interstellar radiation, turbulence, magnetic fields, gravity and gas dynamics, pockets of higher density are formed in these clouds, called molecular cloud cores. Upon the collapse of a molecular cloud core (MCC), the material in the MCC will divide itself between the central body, the protostar, and a disk of material orbiting the protostar. This disk is mostly made up of gas and ∼1% of dust. Because planets are formed from these disks, these are referred to as a protoplanetary disks (PPDs). Observations of both PPDs and exoplanets are improving. However, current instruments are not able to observe planet formation in action. Therefore, models are used to predict the conditions and activities inside PPDs. This is where the availability of the thermo-chemical protoplanetary disk model ProDiMo presents the opportunity to link the observed composition of exoplanets to their formation path. ProDiMo is a 2D steady-state simulation code that solves the radiative and chemical equilibrium selfconsistently. Moreover, it generates a great deal of information about the PPD model. The temperature, pressure, density and chemical composition are just a few of the properties that it provides. Firstly, to benchmark the code, ProDiMo models are compared to a set of simple disk models. The comparison shows that ProDiMo is a very advanced code that is able to predict the PPD environment much better than other models that try to link the formation path to the composition. In addition AA Tau is found to be the most suitable PPD to perform planet formation. Because it is has parameters that are found close to median values. The ProDiMo model is used in combination with a mass accretion scenario. The formation scenario that is applied is called pebble accretion. In this scenario it is proposed that pebbles formed from dust at large radii drift to the inner disk where the pebbles are accreted by a planetesimal. As a result, the planetesimal can grow in mass up to tens of Earth masses (푀⊕), and is now called a core. The moment the core has a high enough mass and the pebble accretion has terminated early in the disk life time, before ∼3 Myr, it becomes a gas giant. This is done by accreting a massive amount of gas from the disk, and thereby clearing an annulus of gas from the disk. In the case of the AA Tau model, gas giants only form at radii between 2 and 8 AU. The largest gas giant at 4 AU has a mass of 110 푀⊕. By combining the model of AA Tau with the pebble accretion scenario, the composition of the resulting gas giants is determined. Planetesimal accretion leads to a stellar C/O of the ices in all of the cores formed between 0.5 and 25 AU. The atmospheres of gas giants formed between 2 and 4.8 AU, with C/O between 1.3 and 13, are up to an order of magnitude away from other similar models and observations. From 4.8 to 8 AU the model predicts a slowly decreasing C/O from 2.2 to 1.3. Compared to observations the C/O ratios computed for the AA Tau model are similar for planets formed beyond 4.8 AU. On the other hand, below 4.8 AU very large differences are seen. However, to determine why there is a large discrepancy between the computed C/O and the observed C/O, further research is required.