Morphological analyses of small and medium size landforms in Scandia Cavi and Olympia Undae, Northern circumpolar region of mars

This article presents a systematic morphological analysis of the topographic landforms at Olympia Undae and Scandia Cavi in the northern circumpolar region of Mars. The study has been performed using images from Mars Express and Mars Reconnaissance Orbiter, as well as topographic profiles from Mars Global Surveyor of 200 small and medium-size geological landforms (16 km diameter on average). The main morphometric parameters of these landforms have allowed their classification into three groups that include cratered structures, non-cratered structures, and complex irregular structures. In the cratered group, three subgroups can be distinguished: cratered cones, impact craters and undifferentiated craters. In turn, the non-cratered group includes two subgroups: peaked domes and simple domes. Their possible relation to internal, surface and impact processes is discussed

Gridmapping the northern plains of Mars: Geomorphological, Radar and Water-Equivalent Hydrogen results from Arcadia Plantia

A project of mapping ice-related landforms was undertaken to understand the role of sub-surface ice in the northern plains. This work is the first continuous regional mapping from CTX (“ConTeXt Camera”, 6 m/pixel; Malin et al., 2007) imagery in Arcadia Planitia along a strip 300 km across stretching from 30°N to 80°N centred on the 170° West line of longitude. The distribution and morphotypes of these landforms were used to understand the permafrost cryolithology. The mantled and textured signatures occur almost ubiquitously between 35° N and 78° N and have a positive spatial correlation with inferred ice stability based on thermal modelling, neutron spectroscopy and radar data. The degradational features into the LDM (Latitude Dependent Mantle) include pits, scallops and 100 m polygons and provide supporting evidence for sub-surface ice and volatile loss between 35-70° N in Arcadia with the mantle between 70-78° N appearing much more intact. Pitted terrain appears to be much more pervasive in Arcadia than in Acidalia and Utopia suggesting that the Arcadia study area had more wide-spread near-surface sub-surface ice, and thus was more susceptible to pitting, or that the ice was less well-buried by sediments. Correlations with ice stability models suggest that lack of pits north of 65-70° N could indicate a relatively young age (~1Ma), however this could also be explained through regional variations in degradation rates. The deposition of the LDM is consistent with an airfall hypothesis however there appears to be substantial evidence for fluvial processes in southern Arcadia with older, underlying processes being equally dominant with the LDM and degradation thereof in shaping the landscape

ASIME 2018 White Paper. In-Space Utilisation of Asteroids: Asteroid Composition -- Answers to Questions from the Asteroid Miners

In keeping with the Luxembourg government's initiative to support the future use of space resources, ASIME 2018 was held in Belval, Luxembourg on April 16-17, 2018. The goal of ASIME 2018: Asteroid Intersections with Mine Engineering, was to focus on asteroid composition for advancing the asteroid in-space resource utilisation domain. What do we know about asteroid composition from remote-sensing observations? What are the potential caveats in the interpretation of Earth-based spectral observations? What are the next steps to improve our knowledge on asteroid composition by means of ground-based and space-based observations and asteroid rendez-vous and sample return missions? How can asteroid mining companies use this knowledge? ASIME 2018 was a two-day workshop of almost 70 scientists and engineers in the context of the engineering needs of space missions with in-space asteroid utilisation. The 21 Questions from the asteroid mining companies were sorted into the four asteroid science themes: 1) Potential Targets, 2) Asteroid-Meteorite Links, 3) In-Situ Measurements and 4) Laboratory Measurements. The Answers to those Questions were provided by the scientists with their conference presentations and collected by A. Graps or edited directly into an open-access collaborative Google document or inserted by A. Graps using additional reference materials. During the ASIME 2018, first day and second day Wrap-Ups, the answers to the questions were discussed further. New readers to the asteroid mining topic may find the Conversation boxes and the Mission Design discussions especially interesting.Comment: Outcome from the ASIME 2018: Asteroid Intersections with Mine Engineering, Luxembourg. April 16-17, 2018. 65 Pages. arXiv admin note: substantial text overlap with arXiv:1612.0070

Origo - an ESA M-class mission proposal to challenge planetesimal formation theories.

The Origo mission was submitted in response to the 2021 call for a Medium-size mission opportunity in ESA's Science Programme.The goal of Origo is to inform and challenge planetesimal formation theories. Understanding how planetesimals form in protoplanetary disks is arguably one of the biggest open questions in planetary science. To this end, it is indispensable to collect ground truths about the physico-chemical structure of the most pristine and undisturbed material available in our Solar System. Origo seeks to resolve the question of whether this icy material can still be found and thoroughly analysed in the sub-surface of comets.Specifically, Origo aims to address the following immediate science questions:Were cometesimals formed by distinct building blocks such as e.g. "pebbles", hierarchical sub-units, or fractal distributions? How did refractory and volatile materials come together during planetesimal growth e.g. did icy and refractory grains grow separately and come together later, or did refractory grains serve as condensation nuclei for volatiles? Did the building blocks of planetesimals all form in the vicinity of each other, or was there significant mixing of material within the protoplanetary disk? To answer these questions Origo will deliver a lander to a comet where we will characterise the first five meters of the subsurface with a combination of remote-sensing and payloads lowered into a borehole. Our instruments will examine the small scale physico-chemical structure. This approach will allow us to address the following objectives, each of which informs the respective science question: Reveal the existence of building blocks of a cometary nucleus from the (sub-)micron to metre scale by exploring unmodified material. Determine the physical structure of these building blocks, in particular, the size distribution of components and how refractory and volatile constituents are mixed and/or coupled. Characterise the composition of the building blocks by identifying and quantifying the major ices and refractory components. Over the past decade, significant theoretical advances have been achieved in working out possible planetesimal formation scenarios.The two leading hypotheses for how planetesimals formed from sub-micron dust and ice particles in the proto-planetary nebula can be classified into two groups:the hierarchical accretion of dust and ice grains to form planetesimals; and the growth of so-called pebbles, which are then brought to gentle gravitational collapse to form larger bodies by e.g. the streaming instability. These competing theories only have indirect proof from observations.Direct evidence, i.e. ground truths, about the building blocks of planetesimals remain hidden. Origo would challenge these theories by examining the physico-chemical structure of the most pristine material available in our Solar System. Though the proposal was not retained for step 2 we present our concept for community discussion

Mars: new insights and unresolved questions

Mars exploration motivates the search for extraterrestrial life, the development of space technologies, and the design of human missions and habitations. Here, we seek new insights and pose unresolved questions relating to the natural history of Mars, habitability, robotic and human exploration, planetary protection, and the impacts on human society. Key observations and findings include: – high escape rates of early Mars’ atmosphere, including loss of water, impact present-day habitability; – putative fossils on Mars will likely be ambiguous biomarkers for life; – microbial contamination resulting from human habitation is unavoidable; and – based on Mars’ current planetary protection category, robotic payload(s) should characterize the local martian environment for any life-forms prior to human habitation.Some of the outstanding questions are:– which interpretation of the hemispheric dichotomy of the planet is correct; – to what degree did deep-penetrating faults transport subsurface liquids to Mars’ surface; – in what abundance are carbonates formed by atmospheric processes; – what properties of martian meteorites could be used to constrain their source locations; – the origin(s) of organic macromolecules; – was/is Mars inhabited; – how can missions designed to uncover microbial activity in the subsurface eliminate potential false positives caused by microbial contaminants from Earth; – how can we ensure that humans and microbes form a stable and benign biosphere; and – should humans relate to putative extraterrestrial life from a biocentric viewpoint (preservation of all biology), or anthropocentric viewpoint of expanding habitation of space?Studies of Mars’ evolution can shed light on the habitability of extrasolar planets. In addition, Mars exploration can drive future policy developments and confirm (or put into question) the feasibility and/or extent of human habitability of space

The Comet Interceptor Mission

Here we describe the novel, multi-point Comet Interceptor mission. It is dedicated to the exploration of a little-processed long-period comet, possibly entering the inner Solar System for the first time, or to encounter an interstellar object originating at another star. The objectives of the mission are to address the following questions: What are the surface composition, shape, morphology, and structure of the target object? What is the composition of the gas and dust in the coma, its connection to the nucleus, and the nature of its interaction with the solar wind? The mission was proposed to the European Space Agency in 2018, and formally adopted by the agency in June 2022, for launch in 2029 together with the Ariel mission. Comet Interceptor will take advantage of the opportunity presented by ESA’s F-Class call for fast, flexible, low-cost missions to which it was proposed. The call required a launch to a halo orbit around the Sun-Earth L2 point. The mission can take advantage of this placement to wait for the discovery of a suitable comet reachable with its minimum ΔV capability of 600 ms−1. Comet Interceptor will be unique in encountering and studying, at a nominal closest approach distance of 1000 km, a comet that represents a near-pristine sample of material from the formation of the Solar System. It will also add a capability that no previous cometary mission has had, which is to deploy two sub-probes – B1, provided by the Japanese space agency, JAXA, and B2 – that will follow different trajectories through the coma. While the main probe passes at a nominal 1000 km distance, probes B1 and B2 will follow different chords through the coma at distances of 850 km and 400 km, respectively. The result will be unique, simultaneous, spatially resolved information of the 3-dimensional properties of the target comet and its interaction with the space environment. We present the mission’s science background leading to these objectives, as well as an overview of the scientific instruments, mission design, and schedule

How to Size an Exoplanet? A Model Approach for Visualization

The realization and experiences with a physical exoplanet model in the education and outreach are described. During the tests with students in the classroom and adults at public demonstrations, the following conclusions were drawn: in the visualization it is effective to connect and install together the models of planets inside and outside the Solar System, where hot Jupiter’s easily fit into the orbit of Mercury. The size of planets and orbital distance could be more effectively visualized with this method, using the Solar System as a context. The exoplanet model helps to expand the imagination of the audience on how does a planetary system look like, what is getting important as diverse views of explanatory systems emerging in recent years. This inexpensive model is useful in the education and outreach above all to make the audience more familiar with the parameters of exoplanets (here sizes, distances and partly masses), and it gives new input also for those persons who regularly read papers and news on exoplanets