During the six Apollo missions, astronauts collected 2196 lunar samples, nearly all of which have been studied over the past five decades. Six Apollo samples remained unexamined until 2019 and were saved to be analyzed by the next generation of lunar scientists using advanced modern laboratory facilities. Now more than 50 years after Apollo, NASA is returning to the Moon with Artemis and will return geologic samples from a different region of the lunar surface than Apollo. Curation will play an instrumental role in helping to prepare for the safe return of these valuable samples, ensuring their integrity during all stages of the missions, and thus maximizing their scientific return. To prepare for the return of these samples, NASA initiated the Apollo Next Generation Sample Analysis (ANGSA) Program to open previously unstudied samples including unopened double drive tube 73002 and 73001 (also vacuum-sealed) from the Apollo 17 mission to the Taurus-Littrow Valley. The ANGSA program was designed to function as a low-cost analog sample return mission and served as a testing ground to understand processes, update techniques, and prepare for the preliminary examination (PE) of the to-be-returned lunar samples with Artemis. New and advanced curation techniques were developed and applied to support the analyses of 73002/73001 during the PE. Furthermore, cutting-edge analytical instruments such as X-ray Computed Tomography were utilized to aid in PE that were unavailable during Apollo. These efforts are equipping the Artemis generation for future lunar missions and lessons learned from the PE of ANGSA samples will be directly applied to Artemis.

The lunar surface exhibits an absorption band near 3 mu m due to hydration, either water or hydroxyl. In most analyses, the band is variable at least in latitude and temperature. Hypotheses for the variability include infilling of the band by thermal emission, migration of molecular water along temperature gradients, and formation and destruction of metastable hydroxyl as solar wind hydrogen diffuses through lunar surface grains. The degree to which lunar soil exhibits an inherent hydration feature in the absence of environmental influences is an open question. The recent opening of Apollo core sample 73001 that was sealed in vacuum on the lunar surface and curated in dry nitrogen since its return from the Moon affords an opportunity to determine if lunar soil exhibits a spectral feature due to hydration isolated from the lunar environment. To that end, near the close of dissection of the core into samples for allocation to the lunar science community, we introduced an infrared spectrometer into the nitrogen purged curation cabinet and collected reflectance spectra of portions of the core between 2 and 4 mu m. We found no evidence of absorption due to hydration to 1.1% band depth uncertainty. The measurements were relative to a diffuse aluminum standard, which itself could possibly absorb light at 3 mu m due to a thin film of water; we estimate a possible negative bias of about 50 mu g/g equivalent water absorption, leading to a final estimate of core water abundance of 50 mu g/g +/- 50 mu g/g. This finding does not contradict prior estimates of lunar surface hydration as core sample 73001 is immature and may not have had sufficient opportunity to gather enough hydrogen from the solar wind or water from micrometeorites to form detectable hydration. After exposure of the core to laboratory atmosphere, a strong 3 mu m absorption developed, equivalent to over 1,000 mu g/g at a rate of about 5 mu g/g per minute, illustrating the sensitivity of lunar materials to water contamination, and the effectiveness of curation of the sample.

Maps of plagioclase, olivine, and pyroxene at 1 km resolution are derived from a combination of data from the Diviner Lunar Radiometer on the Lunar Reconnaissance Orbiter and the Kaguya Multiband Imager. The Diviner instrument features three infrared bands designed to characterize a spectral feature of lunar soils that is sensitive to the average silica polymerization of the surface called the Christiansen Feature, which is directly sensitive to the presence of plagioclase, the dominant lunar silicate. Existing global mineral maps based on near‐IR data largely infer the presence of plagioclase from the bright mineral’s effect on total reflectance, excepting in rare locations where the surface is nearly pure plagioclase and a weak feature in the plagioclase near‐IR spectrum can be relied upon. By integrating both wavelength regions we produced more robust estimates of the abundance of the three dominant minerals. In the process of this work, we also improved the removal of space weathering effects from Christiansen Feature maps, and showed that silica rich compositional anomalies could be reliably detected by decorrelating Christiansen Feature and FeO maps. New silica‐rich locations are reported as are the global abundances of the three major silicates.

Introduction: Over the last decade, the behavior of volatiles on the lunar surface has become an important question in lunar science. This began with the discovery of the Moon-wide 3 μm band by multiple remote sensing instruments: EPOXI High Resolution Instrument, Cassini Visual and Infrared Mapping Spectrometer (VIMS), and the Moon Mineralogy Mapper (M3) [1][2][3]. This band signifies the presence of OH and possibly H2O (collectively referred to as hydration), which is supported by the discovery of hydroxyl with solar wind hydrogen in lunar agglutinate glasses [4] and the detection of an H2O specific 6 um band [5]. Investigations of lunar hydration have important implications for understanding the conditions of the lunar surface environment as well as understanding volatiles on airless bodies throughout the Solar System. The Chang’e 5 sample return mission has returned the first lunar samples since the 1970s, providing an unprecedented opportunity to investigate the behavior of volatiles with the new perspective gained from the remote sensing discoveries. Data in the 3 μm region is complicated by the presence of both emitted and reflected radiation, and there is debate about how to best correct for thermal emission in M3 data, which does not contain any wavelengths beyond 3 μm to constrain thermal models for the data. Bandfield et al. [6] found a 3 μm feature across the Moon, but do not see differences with latitude or lunar time of day. On the other hand, Li et al. [7], Wohler et al. [8], and Honniball et al. [9] see strong strong differences with these parameters. There is coverage of the landing site by data from M3. However, M3 data is limited in its wavelength coverage. A strong test of thermal corrections is their quality at longer wavelengths where thermal emission is increasingly dominant. To deal with this thermal modeling problem, this work uses observations that are taken from the Mauna Kea Observatory using the SPeX infrared cross-dispersed spectrograph at the NASA InfraRed Telescope Facility (IRTF). This instrument collects data from 1.67 to 4.2 μm and the spectral range provides advantages over Moon Mineralogy Mapper data on the same region of the Moon. First, the complete 3 μm feature is covered allowing the whole absorption feature to be observed. Second, the spectrum extends out to longer wavelengths where the thermal emission dominates, allowing for an accurate thermal correction based off of the data. In this work we obtained data of the Change-5 site Figure 1: a. White box contains measured reflectance at 1.7 μm overlain on a context image of the site. b. White box contains total water (OH +H2O ppm). Red points

We measured the multispectral images and a hyperspectral profile during the first dissection pass of core 73002, and here, we present preliminary results. Both multispectral images and hyperspectral data show systematic darkening and reddening from bottom to top of the core, indicating an increasing maturity from the subsurface to surface soils. Our estimated FeO and TiO 2 abundances are 9 (±1) wt% and 1.8 (±0.5) wt%, and their homogeneous distributions imply no compositional stratigraphy was sampled by core 73002. The in situ regolith reworking depth is about 14 cm as inferred from the optical maturity (OMAT) profile, corresponding to a time range of about 61 million years. Mineralogy and Mg# (molar Mg/[Mg+Fe]) calculated using hyperspectral data and radiative transfer modeling show as expected the core is dominated by plagioclase and low‐Ca pyroxene, and the average Mg# is 61 (±10). Our work shows that spectroscopy has a great potential to be applied in the preliminary examination of future extraterrestrial samples from outside of the glovebox.

Earth and Space Science Open Archive This work was has been accepted for publication in Journal of Geophysical Research - Planets. Version of RecordESSOAr is a venue for early communication or feedback before peer review. Data may be preliminary. Learn more about preprints. preprintOpen AccessYou are viewing the latest version by default [v1]Telescopic Observations of Lunar Hydration: Variations and AbundanceAuthors Casey I. Honniball iD Paul G. G. Lucey Chiara M. Ferrari-Wong Abigail Jane Flom Shuai Li Heather M. Kaluna iD Driss Takir See all authors Casey I. HonniballiDCorresponding AuthorUniversity of Hawaii at ManoaiDhttps://orcid.org/0000-0001-8248-8991view email addressThe email was not providedcopy email addressPaul G. G. LuceyUniversity of Hawaii at Manoaview email addressThe email was not providedcopy email addressChiara M. Ferrari-WongUniversity of Hawaii at Manoaview email addressThe email was not providedcopy email addressAbigail Jane FlomUniversity of Hawaii at Manoaview email addressThe email was not providedcopy email addressShuai LiUniversity of Hawaii at Manoaview email addressThe email was not providedcopy email addressHeather M. KalunaiDUniversity of Hawaii at ManoaiDhttps://orcid.org/0000-0002-0398-3888view email addressThe email was not providedcopy email addressDriss TakirNASA JSCview email addressThe email was not providedcopy email address

Prior to 2009, the surface of the Moon was believed to be anhydrous. However, observations by three spacecraft revealed a hydrated surface by reporting a 3 μm absorption band attributed to hydroxyl and possibly molecular water. The Moon Mineralogy Mapper (M3) spectrometer on board the Chandrayaan‐1 spacecraft has been used to study the lunar 3 μm band, but its spectral range ends at 3 μm. The limited wavelength range of M3 has allowed observed variations in the strength of the 3 μm band to be called into question due to uncertainties in thermal corrections. To investigate the validity of variations in the lunar 3 μm band, we used the SpeX infrared spectrograph at the NASA InfraRed Telescope Facility at Maunakea Observatory in Hawai‘i. With SpeX, we are able to obtain lunar data over a wavelength range of 1.67 to 4.2 μm at 1–2 km spatial resolution. The long wavelengths provide strong constraints on separating thermal emission from solar reflectance. We confirm that the 3 μm band varies with lunar time of day as well as with latitude and composition. Pole‐to‐pole observation chords reveal strong variations in abundances of hydroxyl and possibly molecular water. The data reveal a decrease in abundance as lunar noon is approached, an asymmetric trend about the equator that favors the southern latitudes, and higher concentrations in highland regions. The longer wavelengths provided by SpeX have allowed us to examine variations in the 3 μm band and provide definitive evidence that the variations are due to changes in hydration.

Introduction The solar wind has long been hypothesized to be the source of chemical reactions on the lunar surface, implanting hydrogen, and resulting in OH (hydroxyl) [1], H2O (water) [2], and CH4 (methane) [3]. With the collection of new data by several missions, there have been recent discoveries of water and other volatiles on the lunar surface [4, 5, 6, 7]. Along with these discoveries, there are several lines of evidence that hydrocarbons or other organics may be an important volatile species on the Moon: there has been methane detected in lunar samples [3], and in the lunar exosphere [8]; dark lag deposits possibly composed of organic residues topping ice deposits in Mercurys polar deposits, which serve as analogs to lunar polar deposits [9]; carbon-hydrogen bonds detected in lunar glasses prepared to minimize contamination [10]; and organic detections by The Lunar Crater Observation and Sensing Satellite (LCROSS) that impacted a large projectile into the permanently shaded Cabeus crater near the lunar south pole [11]. Infrared spectra of organic contaminants on such minerals as antigorite, muscovite, montmorillonite, and silica gel show organic absorption features at 3.4 μm due to CH2 and 3.5 μm due to CH3 [12]. Similar contaminant features are observed in reflectance spectra of lunar soils prepared with methanol rinses (Figure 1). The goal of this project is to determine if the Moon exhibits a carbon-hydrogen stretch emission feature in the 3.4-3.5 μm band, and if not detected, to establish upper limits on organic abundance. In order to get the spectral, spatial, and lunar TOD coverage necessary to conduct a full search for organic features, we use the SpeX infrared cross-dispersed spectrograph [13] at the NASA InfraRed Telescope Facility (IRTF) at Mauna Kea Observatory, where we can obtain lunar data from 1.67 to 4.2 μm at 1-2 km resolution.