Science Enabling Exploration: Using LRO to Prepare for Future Missions

Discoveries from LRO have transformed our understanding of the Moon, but LRO's instruments were originally designed to collect the measurements required to enable future lunar surface exploration. A high lunar exploration priority is the collection of new samples and their return to Earth for comprehensive analysis. The importance of sample return from South Pole-Aitken is well-established [Jolliff et al., this conference], but there are numerous other locations where sample return will yield important advances in planetary science. Using new LRO data, we have defined an achievability envelope based on the physical characteristics of successful lunar landing sites. Those results were then used to define 1km x 1km regions of interest where sample return could be executed, including: the basalt flows in Oceanus Procellarum (22.1N, 53.9W), the Gruithuisen Domes (36.1N, 39.7W), the Dewar cryptomare (2.2S, 166.8E), the Aristarchus pyroclastic deposit (24.8N, 48.5W), the Sulpicius Gallus formation (19.9N, 10.3E), the Sinus Aestuum pyroclastic deposit (5.2N, 9.2W), the Compton-Belkovich volcanic complex (61.5N, 99.9E), the Ina Irregular Mare Patch (18.7N, 5.3E), and the Marius Hills volcanic complex (13.4N, 55.9W). All of these locations represent safe landing sites where sample returns are needed to advance our understanding of the evolution of the lunar interior and the timescales of lunar volcanism. If LRO is still active when any future mission reaches the surface, LRO's capability to rapidly place surface activities into broader geologic context will provide operational advantages. LRO remains a unique strategic asset that continues to address the needs of future missions

Building on the Cornerstone: Destinations for Nearside Sample Return

Discoveries from LRO (Lunar Reconnaissance Orbiter) have transformed our knowledge of the Moon, but LRO's instruments were originally designed to collect the measurements required to enable future lunar surface exploration. Compelling science questions and critical resources make the Moon a key destination for future human and robotic exploration. Lunar surface exploration, including rovers and other landed missions, must be part of a balanced planetary science and exploration portfolio. Among the highest planetary exploration priorities is the collection of new samples and their return to Earth for more comprehensive analysis than can be done in-situ. The Moon is the closest and most accessible location to address key science questions through targeted sample return. The Moon is the only other planet from which we have contextualized samples, yet critical issues need to be addressed: we lack important details of the Moon's early and recent geologic history, the full compositional and age ranges of its crust, and its bulk composition

Silica coatings on the 1974 Kilauea flow: new SEM and SIMS results and implications for Mars

Despite the predominately mafic character of martian surface rocks, silica-rich materials have long been predicted to occur on Mars; recently, those predictions have been validated. CRISM spectra from numerous regions of Mars have revealed H_2O and OH-bearing phases most consistent with amorphous silica. Additionally, the detection of high-silica materials at Home Plate by MER Spirit implied aqueous alteration and leaching in a volcanic environment [3]. In order to fully understand the environments in which silica-rich materials are formed on Mars, it is useful to study silica in analogous terrestrial settings. We focus on silica and Fe-Ti oxide coatings in the Ka’u Desert on the island of Hawaii, an analog to Mars characterized by low levels of rainfall and strong acid-sulfate alteration processes [4]. Many formation mechanisms for these coatings have been proposed, including dissolution of wind-blown tephra [5], leaching of volcanic glass [6], and vapor deposition [7]. We focus on a suite of samples from the 1974 Kilauea pahoehoe flow, collected in 2003. The chemistry and morphology of these coatings were previously presented [8]. Here we present new morphological, spectral and isotopic analyses of the coating suite. The goal of the study is to characterize the coatings and their formation mechanism and describe the implications for silica mobility on Mars

Sulfate Deposition in Regolith Exposed in Trenches on the Plains Between the Spirit Landing Site and Columbia Hills in Gusev Crater, Mars

During its exploration within Gusev crater between sol 01 and sol 158, the Spirit rover dug three trenches (Fig. 1) to expose the subsurface regolith [1, 2, 9]. Laguna trench (approx. 6 cm deep, approx.203 m from the rim of Bonneville crater) was dug in Laguna Hollow at the boundary of the impact ejecta from Bonneville crater and the surrounding plains. The Big Hole trench (approx. 6-7 cm deep) and The Boroughs trench (approx. 11 cm deep) were dug in the plains between the Bonneville crater and the Columbia Hills (approx.556 m and approx.1698 m from the rim of Bonneville crater respectively). The top, wall and floor regolith of the three trenches were investigated using the entire set of Athena scientific instruments [10]

Selecting and Certifying a Landing Site for Moonrise in South Pole-Aitken Basin

MoonRise is a New Frontiers mission concept to land in the South Pole-Aitken (SPA) basin, collect samples, and return the samples to Earth for detailed mineral, chemical, petrologic, geochronologic, and physical properties analyses to address science questions relevant to the early evolution of the Solar System and the Moon. Science associated with this mission concept is described elsewhere; here we discuss selection of sites within SPA to address science objectives using recent scientific studies (orbital spectroscopy, gravity, topography), and the use of new data (LRO) to certify safe landing sites for a robotic sample return mission such as MoonRise

Mars Exploration Rover Pancam Multispectral Imaging of Rocks, Soils, and Dust at Gusev Crater and Meridiani Planum

Multispectral imaging from the Panoramic Camera (Pancam) instruments on the Mars Exploration Rovers Spirit and Opportunity has provided important new insights about the geology and geologic history of the rover landing sites and traverse locations in Gusev crater and Meridiani Planum. Pancam observations from near-UV to near-IR wavelengths provide limited compositional and mineralogic constraints on the presence abundance, and physical properties of ferric- and ferrous-iron bearing minerals in rocks, soils, and dust at both sites. High resolution and stereo morphologic observations have also helped to infer some aspects of the composition of these materials at both sites. Perhaps most importantly, Pancam observations were often efficiently and effectively used to discover and select the relatively small number of places where in situ measurements were performed by the rover instruments, thus supporting and enabling the much more quantitative mineralogic discoveries made using elemental chemistry and mineralogy data. This chapter summarizes the major compositionally- and mineralogically-relevant results at Gusev and Meridiani derived from Pancam observations. Classes of materials encountered in Gusev crater include outcrop rocks, float rocks, cobbles, clasts, soils, dust, rock grindings, rock coatings, windblown drift deposits, and exhumed whitish/yellowish salty soils. Materials studied in Meridiani Planum include sedimentary outcrop rocks, rock rinds, fracture fills, hematite spherules, cobbles, rock fragments, meteorites, soils, and windblown drift deposits. This chapter also previews the results of a number of coordinated observations between Pancam and other rover-based and Mars-orbital instruments that were designed to provide complementary new information and constraints on the mineralogy and physical properties of martian surface materials

Visible and near-infrared multispectral analysis of rocks at Meridiani Planum, Mars, by the Mars Exploration Rover Opportunity

Multispectral measurements in the visible and near infrared of rocks at Meridiani Planum by the Mars Exploration Rover Opportunity's Pancam are described. The Pancam multispectral data show that the outcrops of the Burns formation consist of two main spectral units which in stretched 673, 535, 432 nm color composites appear buff- and purple-colored. These units are referred to as the HFS and LFS spectral units based on higher and lower values of 482 to 535 nm slope. Spectral characteristics are consistent with the LFS outcrop consisting of less oxidized, and the HFS outcrop consisting of more oxidized, iron-bearing minerals. The LFS surfaces are not as common and appear, primarily, at the distal ends of outcrop layers and on steep, more massive surfaces, locations that are subject to greater eolian erosion. Consequently, the HFS surfaces are interpreted as a weathering rind. Further inherent spectral differences between layers and between different outcrop map units, both untouched and patches abraded by the rover's Rock Abrasion Tool, are also described. Comparisons of the spectral parameters of the Meridiani outcrop with a set of laboratory reflectance measurements of Fe^(3+)–bearing minerals show that the field of outcrop measurements plots near the fields of hematite, ferrihydrite, poorly crystalline goethite, and schwertmannite. Rind and fracture fill materials, observed intermittently at outcrop exposures, are intermediate in their spectral character between both the HFS and LFS spectral classes and other, less oxidized, surface materials (basaltic sands, spherules, and cobbles)

Santorini, Another Meteorite on Mars and Third of a Kind

The Mars Exploration Rover (MER) Opportunity has been studying Meridiani Planum for five years. On sol 1634 of its mission, Opportunity left Victoria crater after investigating it for approximately 682 sols [1] and is now on a journey towards Endeavour, a 24 km diameter crater about 12 km southeast of Victoria. A priority along the way is the investigation of cobbles, which in the jargon of the MER science team denotes any loose rock fragment larger than a couple of centimeters. Cobbles investigated thus far are of diverse origin [2] and provide the only means to investigate material other than the ubiquitous sulfate-rich outcrop, basaltic sand or hematiterich spherules dubbed blueberries. Some of these cobbles are meteorites [3]. Meteorites on Mars are not just a curiosity that make Mars a more Earth-like planet. Metallic iron in meteorites, for example, may be used as a more sensitive tracer for volatile surface interactions compared to igneous minerals [4]. Between sols 1713 and 1749, including the period of Mars solar conjunction, Opportunity investigated a cobble informally named Santorini. Its chemical and mineralogical composition is very similar to Barberton and Santa Catarina, two cobbles that were identified as meteorites and which are probably related to each other [3]. Santorini was investigated with the rover s Panoramic Camera (Pancam), Microscopic Imager (MI), Alpha-Particle X-ray Spectrometer (APXS) and Moessbauer (MB) spectrometer. The miniature Thermal Emission Spectrometer (mini-TES) was not operational at the time. The Rock Abrasion Tool (RAT) could not be used to brush off potential dust coatings because of unfavorable geometry

Noachian Impact Ejecta on Murray Ridge and Pre-impact Rocks on Wdowiak Ridge, Endeavour Crater, Mars: Opportunity Observations

Mars Exploration Rover Opportunity has been exploring Meridiani Planum since January 2004, and has completed 4227% of its primary mission. Opportunity has been investigating the geology of the rim of 22 km diameter Endeavour crater, first on the Cape York segment and now on Cape Tribulation. The outcrops are divided York; (ii) the Shoemaker fm, impact breccias representing ejecta from the crater; into three formations: (i) the lower Matijevic fm, a pre-impact lithology on Cape and (iii) the upper Grasberg fm, a post-impact deposit that drapes the lower portions of the eroded rim segments. On the Cape Tribulation segment Opportunity has been studying the rocks on Murray Ridge, with a brief sojourn to Wdowiak Ridge west of the rim segment. team member Thomas Wdowiak, who died in 2013.) One region of Murray Ridge has distinctive CRISM spectral characteristics indicating the presence of a small concentration of aluminous smectite based on a 2.2 micron Al-OH combination band (hereafter, the Al-OH region)

Iron-Manganese Redox Reactions in Endeavour Crater Rim Apron Rocks

The Mars Exploration Rover Opportunity has been exploring Noachian age rocks and outcrops on the rim of the 22 km diameter Endeavour crater since August 2011. The Cape York area is a low-lying rim of Endeavour that contains 3 distinct lithologies: 1) the stratigraphically lowest Matijevic fm of pre-impact lithology, 2) Shoemaker fm of impact breccias, and 3) the stratigraphically highest rim lithology Grasberg fm of post-impact sediments that drape the lower slopes of the rim. The sulfate-rich sediment of the Burns fm lies unconformably over the Grasberg fm. Ca-sulfate veins were discovered in Grasberg fm sediments; the sulfates precipitated from aqueous fluids flowing upward through these materials. Opportunity investigated the chemistry and morphology of outcrops in the Matijevic fm that have Fe(sup 3+)-rich smectite detected by orbital signatures returned by CRISM on MRO. Matijevic fm also contains "boxwork" fractures with chemistry consistent with an Al-rich smectite and veins that appear to be rich in Ca-sulfate. More recently on Cape Tribulation, Opportunity has characterized two S-, Mg- and Mn-rich rich rocks overturned and fractured by the rover's wheels on Cook Haven. Those rocks have been dubbed "Pinnacle Island" and "Stuart Island" and will be referred to as the "Island" rocks. The objectives of this study are to characterize the Fe and Mn contents in the Cape York materials, including the two Island rocks, and to provide a model for Mn mobilization and precipitation. Detailed geochemistry of Endeavour rim rocks is presented in a companion paper. Geochemical trends and elemental associations were obtained from data returned by the Alpha Particle X-ray Spectrometer (APXS) on Opportunity