The Psyche spacecraft launched on October 13, 2023 to journey to the asteroid of the same name. Psyche is the largest M-class asteroid and possibly the remanent core of an early differentiated planetesimal that was disrupted by collisions. The Psyche mission will test that hypothesis as the 14th mission in NASA’s Discovery Program. An alternative hypothesis is that the asteroid is unmelted primordial material. We describe the proposal competition process leading to selection of the mission and its context with other small body missions. This paper will briefly introduce the three science instruments, gravity science investigation, and Deep Space Optical Communications technology demonstration, leading into a detailed explanation of the science mission architecture. The orbital science phase is divided into a series of circular mapping orbits at four distinct altitudes, each selected to address specific science objectives. The requirements and objectives for each orbit are accompanied by an assessment of the effectiveness of each phase. We discuss the structure of the Psyche team during the operations phase along with the roles and responsibilities of the science and flight operations teams. Key elements of mission operations that are unique to the Psyche mission are provided. The Science Data Center manages and archives the Psyche mission data. The contents of the archive data sets for each instrument are outlined as well as the interfaces between the Science Data Center, the instrument teams, and the Planetary Data System.

The lunar polar regions are high-priority targets for scientific investigation and exploration. To aid these endeavors, we produced enhanced altimetry data from the Lunar Orbiter Laser Altimeter for the north polar region, from which we computed new maps of surface height and slope as well as topographic roughness on horizontal baselines of 100–1600 m. We also produced a new map of permanently shadowed regions (PSRs) that contains fewer artifacts and is higher resolution than previous maps. These new maps were then compared to an analogous set previously produced for the south polar region. Generally, in both polar regions, more steeply sloped terrain is rougher at baselines ≲200 m and has a bluer roughness spectrum, a behavior hypothesized to be due to downslope mass transport. Roughness in the polar regions is also correlated with regolith temperature, and we discuss several possible causes including surface ice in unresolved cold traps, subsurface ice outside cold traps, and changes in the regolith’s geotechnical properties. In the north, there are more PSRs with areas ∼0.1–1.0 km ^2 and fewer with areas >100 km ^2 , which may be due to the north having a higher number of craters with diameters of hundreds of meters to ∼3 km. The new maps presented here have many applications in the scientific study and exploration of the lunar north polar region, such as geologic mapping, modeling of cold traps, landing-site characterization, traverse planning, and the interpretation of in situ and remote-sensing data.

Numerous space agencies are planning sustainable human presence at the lunar south pole. Understanding the nature of the lunar crust, particularly its three-dimensional density structure, is important, for example, for the search for water ice predicted to be present. The paucity of in situ measurements requires that we exploit the knowledge obtained through orbital measurements. Two data sets, gravity and topography, in combination with local geology, can provide constraints on the density of the crust. We analyzed the radial component of the gravity field to determine the density of the crust, which we relate to depth using a point-mass spherical harmonic approach. Our investigation provides estimates of density and density gradient at 20 sites in the south polar region: the original 13 Artemis sites, 5 permanently shadowed regions (PSRs), the south pole, and a site on the floor of the Amundsen crater. We find that the mean density in the top 2–10 km for the six PSRs (2475 ± 108 kg m ^−3 ) is comparable to that (2483 ± 147 kg m ^−3 ) for the 14 non-PSRs. The weighted mean gradient for the five PSRs and the Amundsen floor is 3 times greater than that for the 14 non-PSRs in the 2–4 km depth range; the average density increases with depth at 25 kg m ^−3 km ^−1 . To investigate whether a relationship exists between inferred areal coverage of ice and our density results, we compared densities with results for reflectance in several common PSR localities. We find lower densities and higher gradients for areas characterized by greater areal coverage of ice.

After its successful launch in October 2023, the NASA Psyche mission is currently on its way to asteroid (16) Psyche where it will arrive in 2029. Psyche is the first metal-rich asteroid to be orbited by a spacecraft (Elkins-Tanton et al., 2016). Thus, the Psyche mission plans a detailed geologic and morphologic survey of the asteroid (Jaumann et al., 2022) supported by an extensive imaging campaign conducted by the Psyche Multispectral Imager (Bell et al., 2016; Polanskey et al., 2018). Previous space missions, in particular the Dawn mission at asteroid Vesta (Russell et al., 2013), provide a base for the science and mission operations to collect the desired data (Polanskey et al., 2018).High quality data products including, mosaics and digital terrain models are vital to perform a geologic and geomorphologic analysis, however Psyche is an irregularly shaped body (Shepard et al., 2021) (Figure 1) that makes the illustration and interpretation of such data challenging. Psyche can approximately be described by a bi-axial ellipsoid with axes of 129 km and 86 km (Shepard et al., 2021), resulting in a flattening of 0.33 (the flattening is defined as , where and are the semi-major and semi-minor axes, respectively). As comparison, the also ellipsoidal asteroid Vesta has a flattening of 0.20 with bi-axial axes of 285 km and 229 km.Figure 1: Psyche’s shape from Shepard et al. 2021. The colours illustrate the surface’s distance from the centre with red and blue indicating high and low values, respectively.The Dawn mission conducted an extensive mapping campaign at Vesta (Williams et al. 2014) and although the digital terrain models were referenced to the best fit ellipsoid describing Vesta’s shape, the cartographic products (e.g. maps) were usually presented in a geocentric projection (Roatsch et al. 2012, 2013). This means that images of the surface of Vesta were projected onto a sphere of 255 km radius before being map projected. Although this approach is straight forward and did not hinder the geologic interpretation, the surface images are distorted. As a consequence, measuring feature lengths, such as crater diameters, is incorrect, albeit often negligible in the case of Vesta. However, distortion effects will be significantly increased if such techniques are being applied to even flatter Psyche.To mitigate such distortion effects on Psyche, one could use a mapping tool that enables mapping directly on the three-dimensional surface (Ernst et al.). However, to make use of the full capacity of the data, it is desirable to generate map products that can be used in standard geoinformation systems, such as QGIS. For such tools, a suited image projection needs be applied, that incorporates the ellipsoidal shape of Psyche. An improvement on distortion can be achieved when applying a geodetic projection, which projects surface images though an ellipsoid’s surface normal rather than a central point (Figure 2).Figure 2: Illustration of the geocentric and geodetic latitude of a point on the surface of an ellipsoid.In this work, we will access the effects of Psyche’s ellipsoidal shape on producing and interpreting cartographic products. As a guide to the future generation of Psyche cartographic products, we will show how potential surface features and measurements on Psyche in geocentric projection will be distorted compared to geodetic projections. References:Bell, J., et al., 2016. The Psyche Multispectral Imager Investigation: Characterizing the Geology, Topography, and Compositional Properties of a Metallic World. Presented at the 47th Lunar and Planetary Science Conference, The Woodlands, TX, USA, #1366.Elkins-Tanton, L.T., et al., 2016. Asteroid (16) Psyche: The Science of Visiting a Metal World. Presented at the 47th Lunar and Planetary Science Conference, Woodlands, Texas, USA, #1631.Ernst, C.M., et al., 2018. The Small Body Mapping Tool (SBMT) for Accessing, Visualizing, and Analyzing Spacecraft Data in Three Dimensions, in: 49th Lunar and Planetary Science Conference. Presented at the 49th Lunar and Planetary Science Conference, The Woodlands, Texas, USA, #1043.Jaumann, R., et al., 2022. The Psyche Topography and Geomorphology Investigation. Space Sci Rev 218, 7. https://doi.org/10.1007/s11214-022-00874-7Polanskey, C.A. et al., 2018. Psyche Science Operations Concept: Maximize Reuse to Minimize Risk, in: 2018 SpaceOps Conference. Presented at the 2018 SpaceOps Conference, American Institute of Aeronautics and Astronautics, Marseille, France. https://doi.org/10.2514/6.2018-2703Roatsch, T., et al., 2013. High-resolution Vesta Low Altitude Mapping Orbit Atlas derived from Dawn Framing Camera images. Planetary and Space Science 85, 293–298. https://doi.org/10.1016/j.pss.2013.06.024Roatsch, T., et al., 2012. High resolution Vesta High Altitude Mapping Orbit (HAMO) Atlas derived from Dawn framing camera images. Planetary and Space Science, Solar System science before and after Gaia 73, 283–286. https://doi.org/10.1016/j.pss.2012.08.021Russell, C.T., et al., 2013. Dawn completes its mission at 4 Vesta. Meteorit Planet Sci 48, 2076–2089. https://doi.org/10.1111/maps.12091Shepard, M.K., et al., 2021. Asteroid 16 Psyche: Shape, Features, and Global Map. Planet. Sci. J. 2, 125. https://doi.org/10.3847/PSJ/abfdbaWilliams, D.A., et al., 2014. Introduction: The geologic mapping of Vesta. Icarus, Special Issue: The Geology of Vesta 244, 1–12. https://doi.org/10.1016/j.icarus.2014.03.

Solid-state nanogap systems are an emerging technology for in-situ life detection due to their single-molecule resolution of a wide range of biomolecules, including amino acids and informational polymers, at the parts per billion to trillion level. By targeting the abundance distributions of organic molecules, this technology is a candidate for detecting ancient and extant life and discriminating between biotic and abiotic organics on future planetary missions to Mars and icy moons such as Enceladus and Europa. A benchtop system developed at Osaka University has a proven ability to detect and discriminate among single amino acids, RNA, and DNA using nanogap chips. The Electronic Life-detection Instrument for Enceladus/Europa (ELIE) prototype was subsequently developed to make this technology viable for space instrumentation through the simplification of electronics, reduction of size and weight, and automation of gap formation. Initial ground testing using a manually formed nanogap with the first ELIE prototype detected the amino acid L-proline. However, this manual adjustment approach posed limitations in maintaining a consistent gap size. To address this challenge, we integrated an automated piezo actuator to enable real-time gap control, permitting single-molecule identification of a target amino acid, L-proline, under reduced gravity (g), including Mars (g = 0.378), Europa or Lunar (g = 0.166), and microgravity conditions (g = 0.03-0.06), as validated through parabolic flight testing. Power supply noise and experimental constraints of the experiment design limited data collection to short segments of good-quality data. Nevertheless, the subsequent analysis of detected events within these segments revealed a consistent system performance and a controlled gap size across the different accelerations. This finding highlights the system’s resilience to physical vibrations. Future goals are to progress the instrument towards technology readiness level 4 with further reductions of size and mass, lower noise, and additional system automation. With further development, ELIE has the potential to be an autonomous and sensitive single-molecule detection instrument for deployment throughout the solar system.

Examining the reflectance of the Moon's surface across a broad range of viewing geometries through photometric analysis can reveal physical and geological properties of its regolith. Since 2013 December, the Lunar Orbiter Laser Altimeter (LOLA) on board the Lunar Reconnaissance Orbiter (LRO) has been operating as a near-infrared (1064 nm) passive radiometer when its laser is turned off. We present a new analysis of this data set spanning roughly 8 yr and covering the surface up to high latitudes in both hemispheres. We apply semiempirical phase functions to find a lower photometric slope and a narrower opposition effect for the highlands than the maria, consistent with theoretical expectations given the higher albedo of the highlands. Examining various geological properties at global scales shows that, in the highlands, iron abundance (FeO) and optical maturity (OMAT) are the dominant factors affecting the phase function, with a smaller influence from surface slope. In the maria, FeO is the dominant factor, with smaller influences from OMAT, surface slope, and TiO2. Submicroscopic iron abundance (SMFe) has a similar effect to OMAT in both highlands and maria. Analysis at specific sites, including the Reiner Gamma swirl and several silicic anomalies, indicates that the phase functions are consistent with the global data for similar FeO and OMAT. Thermophysical properties inferred from surface temperature observations by the Diviner Lunar Radiometer Experiment on board LRO do not affect the 1064 nm phase function, possibly due to a difference between their depth scale and LOLA's sensing depth.

Abstract The formation and evolution of the South Pole‐Aitken (SPA) basin is critical to relating large impact basin formation and modification to lunar geophysical evolution. Most prior models of the SPA impact were conducted in 2D, making it difficult to compare model output to the 3D crustal structure and ejecta distribution. In order to better constrain the parameters of the SPA impactor and the expected post impact distribution of crust and ejecta, we conducted numerical simulations of the SPA impact in 3D. We tested a wide range of impact parameters and constrained model results with recent geophysical data. We found the crustal structure of the SPA basin is best fit by an oblique impact (30–45°) of a 350–400 km diameter projectile impacting at 12–16 km/s. The impact excavated material from as deep as 80–120 km, and ejecta was deposited in a butterfly pattern with a forbidden region uprange of the impact.

The lunar gravity field is used to estimate and constrain the depth of mass anomalies under 19 major lunar impact basins. We use radial gravitational spectra, consisting of accelerations computed either per spherical harmonic degree or cumulatively, at surface locations to obtain the distribution of the gravity signal with spherical harmonic degree and, by implication, to the likely depth below the surface. The results provide estimates for the maximum likely depths of the primary component to the mass anomalies under 19 basins. We find that the maximum depths of the primary source of mascon gravity on the lunar nearside are deeper than the depths for those on the farside when South Pole–Aitken (SPA) is excluded. All basin mass anomalies on the lunar nearside are in the mantle. The maximum depth of the primary source of the mass anomalies is <80 km, with the exception of SPA, whose dominant mass signature lies at a maximum depth of >200 km beneath the surface. The upper 20 km under all basins is largely devoid of anomalies, reflecting predominantly mixing and relaxation associated with impact melt combined with ejecta fallback, as well as homogenization associated with post-basin formation impact bombardment. Except for SPA, all basin anomalies merge with the deep interior at ∼150 km or below, indicating the depth penetration of disruption of the density structure of the lunar interior associated with impact bombardment.

Upcoming missions to the lunar south pole require detailed maps over large areas to fully characterize landing sites locally and regionally and to place their data into proper geologic context. To that end, we enhanced the Lunar Orbiter Laser Altimeter altimetry data set for the south polar region, from which we produced new maps of topography, topographic roughness, and permanently shadowed regions (PSRs). The roughness maps reveal a diversity of terrains characterized by hectometer-scale roughness that is controlled in this region primarily by cratering and downslope mass transport. The south polar region is littered with linear roughness features of order ∼1–10 km wide and approximately tens to hundreds of kilometers long hypothesized to be secondary impacts within extended ejecta rays. Nonuniformities in these features could reflect variations in secondary impactor properties and/or target terrain properties. Poleward of 80° S, the PSR cumulative size–frequency distribution (CSFD) shows an approximately power-law behavior whose exponent has a spatial variation of ∼10%. PSRs with areas <1 km 2 contain 15% ± 5% of the total PSR area. Finally, we studied the effect of false positives and false negatives on the accuracy of the measured PSR CSFD and on the area for any individual PSR. The new maps presented here have many applications in the science and exploration of the lunar south polar region, such as geologic mapping and traverse planning.

Growing evidence of the potential habitability of Ocean Worlds across our Solar System is motivating the advancement of technologies capable of detecting life as we know it – sharing a common ancestry or common physicochemical origin to life on Earth – or don’t know it, representing a distinct genesis event of life quite different than our one known example. Here, we propose the Electronic Life-detection Instrument for Enceladus/Europa (ELIE), a solid-state single-molecule instrument payload that aims to search for life based on the detection of amino acids and informational polymers (IPs) at the parts per billion to trillion level. As a first proof-of- principle in a laboratory environment, we demonstrate single-molecule detection of the amino acid L-proline at a 10 µM concentration in a compact system. Based on ELIE’s solid-state quantum electronic tunneling sensing mechanism, we further propose the quantum property of the HOMO–LUMO gap (energy difference between a molecule’s highest energy occupied molecular orbital and lowest energy unoccupied molecular orbital) as a novel approach to measure amino acid complexity. Finally, we assess the potential of ELIE to discriminate between abiotically and biotically derived (-amino acids in order to reduce false positive risk for life detection. Nanogap technology can also be applied to the detection of nucleobases and short sequences of IPs such as, but not limited to, RNA and DNA. Future missions may utilize ELIE to target preserved biosignatures on the surface of Mars, extant life in its deep subsurface, or life or its biosignatures in the plume, surface, or subsurface of ice moons such as Enceladus or Europa. One Sentence Summary: A solid-state nanogap can determine the abundance distribution of amino acids, detect nucleic acids, and shows potential for detecting life as we know it and life as we don’t.

The asteroid (16) Psyche is the target of the NASA Psyche mission, where the magnetometer is one of the three science instruments on board. Its purpose is to prove whether the asteroid formed from the core of a differentiated planetesimal. The magnetometer will measure the magnetic field at different distances from the asteroid in order to detect any remanent magnetization, where a magnetic moment larger than 2×10^14 Am2 could imply that the body once generated a core dynamo, and therefore formed as an igneous differentiation.The Psyche spacecraft carries two three-axis fluxgate magnetometers mounted on a fixed boom at 2.15m and 1.45m, respectively, which provide redundancy and gradiometer capabilities to compensate for spacecraft-generated magnetic fields. The magnetometers will be powered on early in the initial checkout phase and remain on throughout cruise and orbital operations and producing 50 vectors per second. The in-flight temperature of the magnetometers is expected to span a large range, therefore an extensive calibration program has been carried out in order to characterize the instruments and prove the performance pre-flight.

The objective of the Psyche Magnetometry Investigation is to test the hypothesis that asteroid (16) Psyche formed from the core of a differentiated planetesimal. To address this, the Psyche Magnetometer will measure the magnetic field around the asteroid to search for evidence of remanent magnetization. Paleomagnetic measurements of meteorites and dynamo theory indicate that a diversity of planetesimals once generated dynamo magnetic fields in their metallic cores. Likewise, the detection of a strong magnetic moment ( >2×10^14 Am^2 ) at Psyche would likely indicate that the body once generated a core dynamo, implying that it formed by igneous differentiation. The Psyche Magnetometer consists of two three-axis fluxgate Sensor Units (SUs) mounted 0.7 m apart along a 2.15-m long boom and connected to two Electronics Units (EUs) located within the spacecraft bus. The Magnetometer samples at up to 50 Hz, has a range of ±80,000 nT , and an instrument noise of 39 pT axis^-1 3σ integrated over 0.1 to 1 Hz. The two pairs of SUs and EUs provide redundancy and enable gradiometry measurements to suppress noise from flight system magnetic fields. The Magnetometer will be powered on soon after launch and acquire data for the full duration of the mission. The ground data system processes the Magnetometer measurements to obtain an estimate of Psyche’s dipole moment.

&lt;p&gt;Analysis of the lunar Bouguer gravity field under major basins reveals how gravity varies with spherical harmonic degree &lt;em&gt;L&lt;/em&gt; and, potentially, with depth (to relate the two we use a relationship based on point masses).&amp;#160; We have studied 19 lunar basins based upon a GRAIL 1200 degree and order gravity model (GRGM1200B).&amp;#160; The vertical component of Bouguer gravity shows how the gravity is distributed in spherical harmonic degree between the lowest degree, 2, and the highest degree, 1200. Under each basin, this gravity spectrum of accelerations per individual spherical harmonic degree shows a benign region for &lt;em&gt;L&lt;/em&gt; from 800 to 100, a range of approximately 20 km immediately below the surface, consistent with the observation that the upper crust is largely homogenous (Zuber et al., 2013). A region of more varied gravity signal occurs down to &lt;em&gt;L&lt;/em&gt;~20, approximately 60 km deeper. The basin gravity signal merges with the deep interior at &lt;em&gt;L&lt;/em&gt;~10, approximately 150 km below the surface. A set of profiles over latitude or longitude through an individual basin anomaly shows how the magnitude of the gravity signal changes with depth as it passes from the annular moat to the central high of the anomaly; all of which takes place between L~100-20, a depth range estimated to be ~20-80 km.&amp;#160; However, all basins are different to some extent. Outside of the basin anomaly the gravity spectra are relatively benign from just below the surface to L~40, a depth of approximately 45 km and consistent with the approximate average thickness of the lunar crust.&amp;#160; An exception to the general characteristics of the spectra of basins is South Pole-Aitken (SPA) which indicates a structure with few variations that is very similar to the regions that have near zero Bouguer gravity at the surface with no large anomalies in the top 100 km. We interpret this result for SP-A as a result of its largely compensated state.&lt;/p&gt;

Tectonic deformation in the plains of Venus is pervasive, with virtually every area of the planet showing evidence for faulting or fracturing. This deformation can be classified into three general categories, defined by the intensity and areal extent of the surface deformation: distributed deformation, concentrated deformation, and local fracture patterns.

The objective of the NASA Psyche mission gravity science investigation is to map the mass distribution within asteroid (16) Psyche to elucidate interior structure and to resolve the question of whether this metal-rich asteroid represents a remnant metal core or whether it is a primordial body that never melted. Measurements of gravity will be obtained via the X-band telecommunication system on the Psyche spacecraft, collected from progressively lower mapping altitudes. Orbital gravity will allow an estimate of $GM$ to better than 0.001 km3 s−2. A spherical harmonic model of gravity to degree and order 10 will be achievable and, in concert with spherical harmonic data sets from topography and magnetometry, as well as surface composition data, will provide information regarding the spatial and radial distribution of mass that will be used to constrain the origin and evolution of (16) Psyche.

Geodetic and geophysical investigations of the Galilean moon Callisto address fundamental questions regarding the formation and evolution of the Jovian system. Callisto's evolution and internal structure appear to significantly differ from the other Jovian satellites. Similarly-sized Ganymede is a highly evolved ice-rock moon with a differentiated interior, intrinsic magnetic field, and abundant surface evidence of internal activity. In contrast, Callisto's surface is ancient, and Galileo spacecraft data suggest its interior is only incompletely differentiated, despite the presumed presence of a sub-surface ocean. These properties make Callisto uniquely able to constrain the timing and nature of the Jovian system formation. The Magnetics, Altimetry, Gravity, and Imaging of Callisto (MAGIC) mission concept is conceived to fully characterize the properties of this enigmatic moon from its deep interior to the icy shell. Three main instruments are included as a scientific payload. Highly accurate measurements of Callisto's topography, magnetic field, and morphology are obtained by the onboard laser altimeter, magnetometer, and camera, respectively. The telecommunication system supports an additional gravity and radio science investigation. Long- and short-wavelength gravity anomalies afford powerful constraints on internal differentiation and the properties of the hydrosphere (water and ice). Comprehensive numerical simulations and covariance analyses of MAGIC mission scenarios presented in this paper show that the gravitational degree-2 normalized coefficients and the pole obliquity enable the determination of the moment of inertia with an accuracy better than 0.015%. The combination of gravity and altimetry measurements acquired by MAGIC are essential to the characterization of Callisto's interior if - as is likely - the degree-2 gravity includes non-hydrostatic terms. MAGIC's radio science data yield the estimation of Callisto's gravity field with spatial resolutions of <100 km. The combination of gravitational and deformation tides that are retrieved by the radio science and altimetry investigations, respectively, leads to the recovery of the rigid ice shell thickness to within similar to 3 km. Together these datasets would resolve ambiguities inherent in Galileo flyby data, revealing Callisto's interior structure as well as the existence and properties of its postulated internal ocean.

The asteroid (16) Psyche may be the metal-rich remnant of a differentiated planetesimal, or it may be a highly reduced, metal-rich asteroidal material that never differentiated. The NASA Psyche mission aims to determine Psyche’s provenance. Here we describe the possible solar system regions of origin for Psyche, prior to its likely implantation into the asteroid belt, the physical and chemical processes that can enrich metal in an asteroid, and possible meteoritic analogs. The spacecraft payload is designed to be able to discriminate among possible formation theories. The project will determine Psyche’s origin and formation by measuring any strong remanent magnetic fields, which would imply it was the core of a differentiated body; the scale of metal to silicate mixing will be determined by both the neutron spectrometers and the filtered images; the degree of disruption between metal and rock may be determined by the correlation of gravity with composition; some mineralogy (e.g., modeled silicate/metal ratio, and inferred existence of low-calcium pyroxene or olivine, for example) will be detected using filtered images; and the nickel content of Psyche’s metal phase will be measured using the GRNS.

Detailed mapping of topography is crucial for the understanding of processes shaping the surfaces of planetary bodies. In particular, stereoscopic imagery makes a major contribution to topographic mapping and especially supports the geologic characterization of planetary surfaces. Image data provide the basis for extensive studies of the surface structure and morphology on local, regional and global scales using photogeologic information from images, the topographic information from stereo-derived digital terrain models and co-registered spectral terrain information from color images. The objective of the Psyche topography and geomorphology investigation is to derive the detailed shape of (16) Psyche to generate orthorectified image mosaics, which are needed to study the asteroids’ landforms, interior structure, and the processes that have modified the surface over geologic time. In this paper we describe our approaches for producing shape models, and our plans for acquiring requested image data to quantify the expected accuracy of the results. Multi-angle images obtained by Psyche’s camera will be used to create topographic models with about 15 m/pixel horizontal resolution and better than 10 m height accuracy on a global scale. This is slightly better as global imaging obtained during the Dawn mission, however, both missions yield resolutions of a few m/pixel locally. Two different techniques, stereophotogrammetry and stereophotoclinometry, are used to model the shape; these models will be merged with the gravity fields obtained by the Psyche spacecraft to produce geodetically controlled topographic models. The resulting digital topography models, together with the gravity data, will reveal the tectonic, volcanic, impact, and gradational history of Psyche, and enable co-registration of data sets to determine Psyche’s geologic history.

Changes in mass distribution affect the gravitational figure and reorient a planetary body’s surface with respect to its rotational axis. The mass anomalies in the present-day lunar gravity field can reveal how the figure and pole position have evolved over the Moon’s history. By examining sequentially each individual crater and basin, working backward in time order through the catalog of nearly 5200 craters and basins between 1200 and 20 km in diameter, we investigate their contribution to the lunar gravitational figure and reconstruct the evolution of the pole position by extracting their gravitational signatures from the present-day Moon. We find that craters and basins in this diameter range, which excludes South Pole–Aitken, have contributed to nearly 25% of the present-day power from the Moon’s degree-2 gravitational figure and resulted in a total displacement of the Moon’s pole by ∼10° along the Earth–Moon tidal axis over the past ∼4.25 billion years. This also implies that the geographical location of the Moon’s rotational pole has not moved since ∼3.8 Ga by more than ∼2° in latitude owing to impacts, and this has implications for the long-term stability of volatiles in the polar regions.