UK Mars Research and Priorities in the Aurora Programme

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provided by Stirling Online Research Repository Bridges, Hagermann: Meeting report UK Mars research and priorit ies in the Aurora programme

Meeting report John Bridges and clastic solifluction lobes. The low density of through the atmosphere; its currently envisaged Axel Hagermann summarize an impact craters suggests these terrains formed orbital inclination of 72° will allow coverage of in a geologically recent era. Kate Goddard et al. about 95% of the planet. Much of the motiva- RAS Special Discussion Meeting (Imperial College) presented a study of youthful tion behind this mission comes from the reports in January 2011, which looked gullies and depositional fans on Mars in Mojave of seasonally and latitudinally variable meth- Downloaded from https://academic.oup.com/astrogeo/article-abstract/52/2/2.34/206693 by University of Stirling user on 13 February 2019 at the prospects for the UK Crater. Understanding the role of water or other ane plumes at concentrations between 10 and exploring Mars. processes, including CO2 ice sublimation, in 60 ppb. These are based on both ground-based the formation of such gullies is a crucial way of infrared observations (Mumma et al. 2009) and reaching a more accurate understanding of mar- on Mars Express orbiter measurements igh-resolution imaging and near-infra- tian climate variations within the last few mil- (Formisano et al. 2004). As methane red mapping of the martian surface, lion years. Balme and Gallagher speculated that is a known potential biomarker there Htogether with detailed studies of mar- because perchlorates (identified at the Phoenix has been much discussion about the tian meteorites and exobiology research, have landing site) have eutectic temperatures below significance of this data. Our knowl- revealed an increasing amount of detail about 240 K and can remain liquid at temperatures far edge on the encapsulation and reten- how climate and surface processes have changed below the freezing point of water, perchlorate tion of methane in rocks is poor. over the history of Mars. The exploration of brines may explain freeze–thaw processes and Current research at the University of Mars is now being planned through a joint could cause geomorphological changes. Aberdeen focuses on the potential NASA–ESA programme. New missions such of methane-rich rocks to support as the Mars Science Laboratory in 2012 and Climate life. John Parnell et al. described the Trace Gas Orbiter in 2016 will also improve The ancient climate was studied by Peter Grin- how mass spectrometer measure- our understanding about the evolution of Mars. drod (University College London) using the ments could be used to learn more Mission planning is being guided by recent near-infrared surface-mapping instrument about how methane is trapped reports of methane in the Mars atmosphere CRISM, which is on board the Mars Recon- and released in rocks, thereby and the identification of minerals and landforms naissance Orbiter. This work was able to dem- contributing towards predict- associated with water such as the Eberswalde onstrate that a set of sediments in part of the ing the habitability of martian Delta. Mars research is also acting as a spur for Coprates Chasma system of rifts (figure 1) has rocks on future missions. the development of mission concepts and ana- preserved a record of changing aqueous environ- However, Zahnle et al. lytical techniques such as new XRD techniques, ment and chemistry. In another example of the (2010) recently suggested microRaman and a Life Marker Chip. use of CRISM, Kathryn Hill and John Bridges et that methane from the ter- The second UK in the Aurora Programme al. (Leicester) showed that other interior layered restrial atmosphere might meeting was held on 14 January 2011 at Bur- sediments (ILD) in craters of the Arabia Terra have obscured ground- lington House, London. The aim was to bring region had an anhydrous mineralogy, consist- based data on Mars and together researchers, particularly in the field of ent in this case with deposition from air rather thus confused the iden- Mars research and instrumentation, in order to than water. Nicholas Warner et al. (Imperial) tification of martian provide a platform to show our research and to used new high-resolution imagery and digital trace gases. They also discuss what the priorities for future missions terrain models (DTMs) to show that some of the noted the current within Aurora should be. The Aurora pro- terrains associated with floods such as Ares Val- absence of gramme encapsulates Europe’s current plans, lis (near the 1997 Pathfinder landing site) had aiming to send unmanned spacecraft to explore undergone multiple floods rather than single, our neighbouring world to examine its climate, isolated events. Thus current research is show- search for evidence of past or present life, and ing the complexity and variability of past depo- learn how conditions there relate to those on sitional environments. We are moving on from 1 Earth. The meeting was introduced by Freder- considering Mars as divided simply into a warm 1: Perspective view of light-toned layered deposits ick Taylor (Oxford). and wet ancient (Noachian) era, pre‑3.7 Ga, and at the base of a 3.5 km deep trough in Coprates High-resolution imagery of some of the surface a cold and dry Mars after that. Uncertainty in Catena. The 1 m digital elevation model was made by of Mars using the HiRise camera on the Mars the ages of some of the landforms, including the combining stereo HiRISE images of ~0.25 m/pixel. Image is approximately 7 km wide, with no vertical Reconnaissance Orbiter (MRO) at 25 cm/pixel Eberswalde Delta which is one of the Mars Sci- exaggeration. has changed our view of the evolution of its sur- ence Laboratory (MSL) candidate landing sites face and climate. One of the ways our view of and considered to have formed through influx 2: Sky Crane: proposed landing system for ExoMars Mars has changed is the recognition of the influ- of sediment into a standing body of water (Matt and Max-C (and MSL). ence of glacial and periglacial activity in shap- Golombek, Jet Propulsion Laboratory), is part 3: Martian meteorite alteration: Fe-carbonate, ing landscapes. Matt Balme (Open University) of this change in our view of the martian past. phyllosilicate (smectite and serpentine) with an and Peter Gallagher (Trinity College Dublin) One set of presentations at the RAS meet- amorphous gel in the middle. presented new observations of periglacial landing concentrated on instruments for the 2016 forms that appear to have been formed by water ExoMars Trace Gas Orbiter (TGO). This will as part of freeze–thaw cycles: self-organized have a 400 km, near-circular orbit with solar patterns of stone stripes, polygons, circles and occultation and near-nadir measurements

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a plausible model to explain how methane could dimensional dust transport, water cloud aerosol TGO is to monitor active geological processes be released and trapped on short timescales. and chemical species, as discussed by Stephen on Mars. This is a response both to the poten- Thus the abundance and variability of meth- Lewis et al. (Open University). tial existence of active trace gas seeps and to ane on Mars remains uncertain, and its true The ExoMars TGO Mars Climate Sounder the recent identification of active geological nature will not be established without detailed (EMCS), with key components provided by processes, in particular dune systems, recent Downloaded from https://academic.oup.com/astrogeo/article-abstract/52/2/2.34/206693 by University of Stirling user on 13 February 2019

mapping of the atmosphere by TGO at parts- Oxford, Reading and Cardiff universities, impact sites, avalanches, gullies and CO2 gas per-trillion levels, together with more accurate will perform continuous observations of the jets. The colour capabilities of HiSCI are well global circulation models that include three- atmosphere, described by Patrick Irwin et al. suited to this task. (Oxford). This is a development of the suc- Nick Thomas (University of Bern), who is co- cessful EMCS already in orbit about Mars PI of the instrument with the University of Ari- on NASA’s Mars Reconnaissance Orbiter. zona, described how the HiSCI camera (High EMCS will continue the monitoring of Resolution Stereo Colour Imager) will enable Mars global temperature/pressure/aero- increased coverage of Mars at 2 m/pixel. There sol field, and will also be able to meas- is also a need for increased coverage of Mars ure the vertical profile of water vapour with high-resolution DTMs as HiRise will only across the planet up to 50 km alti- cover a small fraction of the planet’s surface; tude. Another instrument selected HiSCI is designed to meet this requirement as for TGO is NOMAD, the “Nadir well. As well as analysing the geomorphology and Occultation for MArs Dis- of the planetary surface, these will allow future covery” spectrometer suite. landing site planning. The instrument is designed for spectroscopic measurements Rovers of features associated with The University of Leicester is leading a UK team hydrocarbons, including with MSSL/UCL and the British Geological methane, in the UV, vis- Survey to collaborate on the HiSCI instrument ible and IR range in solar planning and science exploitation of the upcom- occultation, nadir and ing generation of rover missions. Part of this limb modes. The Open involves developing improved and more auto- University is involved mated techniques for the production of DTMs in this instrument from different datasets and the extraction of and plans to provide data such as surface roughness, described by the UVIS channel, Jan-Peter Muller et al. (UCL, MSSL). This will reported Man- also be of great use in landing site selection ish Patel et al. and detailed characterization for the ExoMars One of the lander to be launched in 2018. Current mis- aims of sion planning involves landing with Sky Crane technology (figure 2; the same as is being used for the 2012 NASA Mars Science Laboratory rover) together with a NASA-led rover MAX-C. The recent Decadal Review of planetary science has proposed limiting the 2018 landers in order to save $1 billion; thus the exact architec- 2 3 ture of the 2018 mission remains to be deter- mined. Golombek (Jet Propulsion Laboratory) described his experience in landing site selection with NASA Mars missions, especially the Mars Science Laboratory with Sky Crane, and outlined the initial engineering constraints possible for the 2018 landing: below 1 km elevation and between 25°N and 5°S latitude. Sky Crane will allow landing accuracy of about a 20 km landing ellipse, compared to 150 km for the current MER rovers. The MAX-C rover will be capable of storing samples for a subsequent Mars Sample Return mission in the 2020s. Elie Allouis et al. (Astrium Ltd) showed the results of a project to build a “breadboard” prototype

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weathering reactions are extensive, chemolitho- trophic reactions which provide energy sources for life could be sustained. New type of lander Within the Aurora programme, up to Mars Sam- ple Return in the 2020s, exploration is planned using rovers or, in the case of a seismic network mission, static landers, as discussed by Agustin Chicarro (European Space Agency). However, Hugo Williams et al. (Leicester) argued the need Downloaded from https://academic.oup.com/astrogeo/article-abstract/52/2/2.34/206693 by University of Stirling user on 13 February 2019 for new lander technologies. They described a Mars Reconnaissance Lander concept which

would use a CO2-rocket-propelled vehicle capable of travelling several kilometres in a ballistic “hop”. This makes use of a radioisotope heat source which recharges a heat capacitor after each hop. This type of exploration vehicle would have the advantage of being able to travel hun- dreds of kilometres, reach higher elevations and traverse rougher terrains than rovers are likely to be capable of. 4: This HiRISE image shows the “Starfish” area of the south polar region of Mars. It reveals a large number of fan-shaped deposits which appear to be the result of a geyser-like process involving The Mars mission plans described are now being jointly formulated with NASA and ESA. CO2 (see Hansen et al. 2010 and Thomas et al. 2010, 2011). UK involvement is being managed by the newly established UK Space Agency (UKSA). In a of a mechanism for moving samples from a drill trometer (MarsXRD) (Kathryn Hill, Graeme discussion at the end of the meeting about pri- to a container and then to an ascent vehicle. Hansford, Richard Ambrosi et al.). orities for future missions beyond ExoMars in The UK planetary science community has Further research related to instrumentation 2018, Sue Horne outlined the UKSA view on the long had an interest in sample return missions, of the ExoMars rover is being carried out at potential Aurora mission following ExoMars. such as the Comet Wild2 samples from Stardust UCL/Birkbeck (Claire Cousins et al.), where This mission would be either a Network sci- currently being analysed at Leicester, Kent, the the filters for the stereo camera system PanCam ence mission studying the structure of Mars; NHM, Manchester and Open University. are being studied. The filter set, virtually Phobos/Demos sample return; precision land- The complexity of a Mars Sample unchanged since it was conceived for ing with a rover; or an orbiter which would be Return mission would require One Mars Pathfinder in 1997, is being an element of the MSR mission capturing the international co-operation lander‘‘ concept redesigned with the astrobiol- MSR ascent vehicle to return 500 g of sam- and a way that the UK might uses a CO -rocket- ogy focus of ExoMars in ples to Earth. In the current NASA plans the contribute would be to host a 2 mind. Jan-Peter Muller et al. returned sample could be collected by MAX-C. sample return facility. propelled vehicle (MSSL, UCL) also showed Although not directly in Aurora, collaboration John Vrublevskis et al. capable of travelling how PanCam could be used with NASA on an asteroid sample return mis- (SEA Ltd) outlined how several kilometres to detect fluorescent spectra sion is also possible. Horne suggested that it is COSPAR Planetary Protec- in a ‘hop’ and so potentially reveal poly- unlikely that the UK could afford involvement tion Policy places very stringent ’’ cyclic aromatic hydrocarbon in both a Mars mission and the ESA mission requirements on sample return signatures. These instruments are Lunar Lander in the same timeframe. ● missions and “breaking the chain of being designed so that they are ready contact” between Earth and, in this case, Mars. to find the relict traces of water. An important John Bridges, Space Research Centre, Dept of Any contamination or damage to the sample way of understanding how interaction with Physics & Astronomy, University of Leicester, must be avoided until it can be confirmed as water changed the Mars crust is through the UK, [email protected]. Axel Hagermann, PSSRI, not presenting a biohazard and available for study of martian meteorites. Leon Hicks, John CEPSAR, The Open University, Milton Keynes, UK. subsequent scientific investigation. A sample Bridges and Hitesh Changela (Leicester) showed return facility has never been built before and transmission electron microscopy and XANES References Vrublevskis outlined an investigation they had analyses from the Diamond synchrotron which Formisano V et al. 2004 Science 306 1758–1761. Hansen C J T et al. 2010 Icarus 205 283. made to determine a preliminary design for it. revealed the nature of a hydrothermal event that Mumma M J et al. 2009 Science 323 1041–1045. UK-based institutions are also developing precipitated Fe carbonate, smectite clay and Zahnle K set al. 2010 I there methane on Mars? Icarus hardware contributions for in situ exploration Fe-serpentine (figure 3). The latter could have in press. applications such as the ExoMars rover. Part of been associated with the production of meth- Thomas N et al. 2010 Icarus 205 296–310. Thomas N 2011 Icarus http://dx.doi.org/10.1016/ the current planned payload is a Life Marker ane. The Leicester team argues that the fluid j.icarus.2010.12.016. Chip (LMC) to detect organic molecules. The event was initiated by an impact (crater diam-

LMC is led by the Space Research Centre, Uni- eter Dc 1–10 km) with rapid cooling. Impacts are Further reading versity of Leicester, which is also designing one potential habitat for life on Mars. Charles MEPAG ND-SAG 2008 Science Priorities for Mars Sample Return unpublished white paper, 70 pp, detectors for the Raman Laser Spectrometer to Cockell (Open University) demonstrated that posted March 2008 by the Mars Exploration Program identify minerals and organics (Mark Sims, Ian volcanic environments were also a likely habitat Analysis Group (MEPAG) at http://mepag.jpl.nasa. Hutchinson et al.) and a dual XRD/XRF spec- for microbial life on Mars. He argued that where gov/reports/index.html.

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