adsabs/AstroCLIMB huggingface dataset:
Paper: The Influence of Internal Structure on Physical Outcomes of the 2029 Apophis Close Approach with Earth
Authors: Joseph V. DeMartini, Derek C. Richardson, Naomi Murdoch, Raphaël F. Garcia, Nicholas C. Schmerr, Petr Scheirich, Ronald-L. Ballouz, Adriana Daca
Figure caption: Histogram of period changes at the end of encounter simulations in the simulation suite over different internal configurations, relative to the spin period at the start of the simulations, for all simulations in this suite. Strong encounters (with the principal axis pointed toward Earth at the time of perigee) are shaded blue, while weak encounters (minor axis pointed toward Earth at perigee) are shaded orange. The distribution is bimodal and narrow, with strong encounters showing a slight decrease in period (spinning faster by 5–15 minutes) and weak encounters showing a slight increase in period (spinning slower by 5–15 minutes) of roughly equal magnitudes. These differences on the scale of several minutes are very small compared to the overall effective rotation period of 30.56 hr. The narrow bimodal distribution arises from the way the encounter orientations are prepared to engineer the strongest and weakest encounters, as discussed in Section 2.2.
Paper: The Influence of Internal Structure on Physical Outcomes of the 2029 Apophis Close Approach with Earth
Authors: Joseph V. DeMartini, Derek C. Richardson, Naomi Murdoch, Raphaël F. Garcia, Nicholas C. Schmerr, Petr Scheirich, Ronald-L. Ballouz, Adriana Daca
Figure caption: Power spectrum for a particle located in the shallow subsurface during the simulated Apophis encounter, the same particle for which a single event is shown in Figure 11. (a) Acceleration seismogram for the Z component of motion, with the timing of the perigee indicated by the dashed red line. (b) Power spectral density spectrogram for the seismogram shown in panel (a), calculated with a 200 s moving window with 75% overlap. Decibels are referenced to 1 m s−2. (c) Probability density function for the power spectrum in panel (b). The probability density function is calculated for 3600 s long time windows and 1 dB bin sizes. The median background spectrum is indicated in cyan.
Paper: Effect of Regolith–Ice Stratigraphy and Laser Weathering on Ultraviolet–Visible–Near-infrared Detection of Lunar Water Ice
Authors: Abhay Vidwans, Jeffrey Gillis
Figure caption: Reflectance spectra of regolith–ice mixtures in different configurations before and after weathering, without (left column) and with (right column) continuum removal. (a), (b) Deposited water (scenario 1) with inset plot magnifying absorption features. (c), (d) Subsurface water (scenario 2). (e), (f) Uniform water–simulant mixture (scenario 3). Vertical lines indicate weaker absorption bands. Spectra were smoothed by 20-point boxcar averaging. Error bars represent the standard deviation across three scans.
Paper: Effect of Regolith–Ice Stratigraphy and Laser Weathering on Ultraviolet–Visible–Near-infrared Detection of Lunar Water Ice
Authors: Abhay Vidwans, Jeffrey Gillis
Figure caption: Icy simulant samples inside the vacuum chamber before weathering (left column) and after weathering (right column). (a), (b) Simulant with deposited water ice. (c), (d) Subsurface water–simulant sample. (e), (f) Uniform water–simulant sample. Dotted circles indicate where spectra were collected (1 cm diameter). The square copper sample holder is 1.5 × 1.5 inches.
Paper: Effect of Regolith–Ice Stratigraphy and Laser Weathering on Ultraviolet–Visible–Near-infrared Detection of Lunar Water Ice
Authors: Abhay Vidwans, Jeffrey Gillis
Figure caption: Experimental setup. The simulant–water mixture or dry simulant is placed inside a vacuum chamber onto a cold head. Under ultrahigh vacuum, the simulant is cooled and churned via laser irradiation, and reflectance spectra are collected.
Paper: Effect of Regolith–Ice Stratigraphy and Laser Weathering on Ultraviolet–Visible–Near-infrared Detection of Lunar Water Ice
Authors: Abhay Vidwans, Jeffrey Gillis
Figure caption: Continuum-removed (top) and absolute (bottom) reflectance spectra comparing deposited and subsurface ice before laser weathering. Although the subsurface water lacked characteristic absorption bands in the NIR, spectra in the UV–vis were nearly identical.
Paper: Effect of Regolith–Ice Stratigraphy and Laser Weathering on Ultraviolet–Visible–Near-infrared Detection of Lunar Water Ice
Authors: Abhay Vidwans, Jeffrey Gillis
Figure caption: Reflectance spectra collected during ice deposition onto cold head at 20 K, from 0 to 18 minutes. Absorption features (1.25, 1.5, 1.65, 2, 2.5 μm) deepen as the ice layer builds. A feature at 1.1 μm becomes prominent for the thickest layers.
Paper: Effect of Regolith–Ice Stratigraphy and Laser Weathering on Ultraviolet–Visible–Near-infrared Detection of Lunar Water Ice
Authors: Abhay Vidwans, Jeffrey Gillis
Figure caption: Liquid injection feedthrough.
Paper: Effect of Regolith–Ice Stratigraphy and Laser Weathering on Ultraviolet–Visible–Near-infrared Detection of Lunar Water Ice
Authors: Abhay Vidwans, Jeffrey Gillis
Figure caption: Dry LHS-1D simulant. The simulant exhibited a flat continuum in the vis–NIR, ideal for detecting water bands in this region.
Paper: A New Global Perspective on Recent Tectonism in the Lunar Maria
Authors: C. A. Nypaver, T. R. Watters, M. E. Banks, J. D. Clark, T. Frueh
Figure caption: (A) An SMR cluster in Mare Humorum containing several north–south oriented SMR segments (white arrows; LROC NAC M1203880892R, M1234474596L, and M1234474596R). (B) Several impact craters (100–250 m diameter) that have been crosscut and tectonically altered by an SMR segment (red arrows). (C) Meter-scale extensional features (yellow arrows) that are oriented perpendicular to a central SMR segment. (D) Two smaller impact craters (20–30 m diameter) that have been crosscut and tectonically altered by an SMR segment (green arrows) [Image credit: NASA/GSFC/Arizona State University.]
Paper: A New Global Perspective on Recent Tectonism in the Lunar Maria
Authors: C. A. Nypaver, T. R. Watters, M. E. Banks, J. D. Clark, T. Frueh
Figure caption: A ridge-adjacent SMR cluster in N. Mare Imbrium overlaid by denotative polyline features (NAC M1144922100).
Paper: Differentiation, the Exception, Not the Rule: Evidence for Full Miscibility in Sub-Neptune Interiors
Authors: Edward D. Young, Aaron Werlen, Sarah P. Marcum, Lars Stixrude, Cornelis P. Dullemond
Figure caption: Isothermal, isobaric projections of the Gibbs free-energy-of-mixing surface in the MgSiO3–Fe–H2 system at six different temperatures and pressures along a nominal T–P path through our fiducial sub-Neptune planet. Concentrations are in mole fractions. The dark gray region is the region of spontaneous exsolution into two phases and is defined by the spinodals (black curves). The blue curves are the binodals defining the coexisting compositions for two stable phases. Example pairs of coexisting compositions are shown by the tie lines between two binodes (blue points) on the binodals. The bulk composition of our reference sub-Neptune with 2 wt% H2 is shown by the circled Neptune symbol. The bulk composition for Earth, including H in the metal core (E. D. Young et al. 2023), and the bulk composition of Neptune are also shown for reference.
Paper: Differentiation, the Exception, Not the Rule: Evidence for Full Miscibility in Sub-Neptune Interiors
Authors: Edward D. Young, Aaron Werlen, Sarah P. Marcum, Lars Stixrude, Cornelis P. Dullemond
Figure caption: Comparison of two models for a fiducial sub-Neptune. In both cases, the planets have identical masses of 6 M⊕, equilibrium temperatures of 900 K, and bulk H2 concentrations of 2% by mass. In panel (A), the planet is an “unequilibrated” structure composed of a pure Fe metallic liquid core overlaid by a MgSiO3 melt with a specified concentration of H2 to match the fully miscible case in panel (B), in turn overlaid by a pure H2-rich envelope. The silicate–envelope boundary is specified to be the same T and P as the binodal in panel (B). The planet in panel (B) is composed of a supercritical magma ocean that is a fully miscible ternary mixture of MgSiO3, Fe, and H2. The surface of the magma ocean is defined by the MgSiO3–H2 binodal, where T = 3594 K and P = 4.0 GPa for the melt H2 concentration of 1.3% by mass. Note that the mass densities are given in kg m−3.
Paper: Differentiation, the Exception, Not the Rule: Evidence for Full Miscibility in Sub-Neptune Interiors
Authors: Edward D. Young, Aaron Werlen, Sarah P. Marcum, Lars Stixrude, Cornelis P. Dullemond
Figure caption: A ternary phase diagram for the system MgSiO3–Fe–H2 at T = 5318 K and P = 13.5 GPa. Regions of one-phase stability that lie outside of both the spinodal and binodal curves are shown in pale gray. Regions inside of the spinodals where two liquid phases are ensured are shown in darker gray. The binodals are shown by the blue curves, and coexisting phase compositions for a given bulk composition are shown by the tie lines connecting individual binodes. Regions of two-phase metastability are between the spinodals and binodals and shown in sky blue. Reference planet bulk compositions projected into this ternary space, in mole fractions, are shown for Earth (⊕), our fiducial sub-Neptune , and Neptune , with the weight fractions of H2 being 0.17%, 2%, and 20%, respectively.
Paper: Differentiation, the Exception, Not the Rule: Evidence for Full Miscibility in Sub-Neptune Interiors
Authors: Edward D. Young, Aaron Werlen, Sarah P. Marcum, Lars Stixrude, Cornelis P. Dullemond
Figure caption: Pressure as a function of radial position along an isentrope in the interior of our fiducial sub-Neptune with a fully miscible core. The envelope–core interface is at R/Rc = 1, where Rc is the radius of the interior exclusive of the outer hydrogen-rich envelope (the “core”). The planet total mass is 6 M⊕ and has a bulk H2 concentration of 2% by mass. The positions of the isobaric, isothermal phase diagrams in Figure 10 are shown for reference.
Paper: Differentiation, the Exception, Not the Rule: Evidence for Full Miscibility in Sub-Neptune Interiors
Authors: Edward D. Young, Aaron Werlen, Sarah P. Marcum, Lars Stixrude, Cornelis P. Dullemond
Figure caption: Comparison of two models for a fiducial sub-Neptune. In both cases, the planets have identical masses of 6 M⊕, equilibrium temperatures of 900 K, and bulk H2 concentrations of 2% by mass. In panel (A), the planet is composed of a pure Fe metallic liquid core overlaid by a supercritical mixture of MgSiO3 and H2, which is in turn overlaid by a H2-rich envelope. The silicate–envelope boundary is the binodal (solvus) at a pressure of 4 GPa. The planet in panel (B) is the same as in Figure 12(B) and is a fully miscible ternary mixture of MgSiO3, Fe, and H2.
Paper: Differentiation, the Exception, Not the Rule: Evidence for Full Miscibility in Sub-Neptune Interiors
Authors: Edward D. Young, Aaron Werlen, Sarah P. Marcum, Lars Stixrude, Cornelis P. Dullemond
Figure caption: Changes in the topology of the ternary phase diagram shown in Figure 10(D) with variations in the interaction parameter LAC = LCA by +20% and −20%.
Paper: The Influence of Internal Structure on Physical Outcomes of the 2029 Apophis Close Approach with Earth
Authors: Joseph V. DeMartini, Derek C. Richardson, Naomi Murdoch, Raphaël F. Garcia, Nicholas C. Schmerr, Petr Scheirich, Ronald-L. Ballouz, Adriana Daca
Figure caption: Diagrams showing packing distributions (panels (a), (c), and (e)) and contact-binary configurations investigated in the simulation suite over different internal configurations (panels (b), (d), and (f)), with labels matching those used in Figures 14–17 in the upper left corner of each frame. (a) HCP distribution: the most compact possible configuration of monodisperse spheres. (c) RPP distribution, which uses a size distribution of randomly packed single spheres. (e) MAP distribution, which uses an equal mixture of irregular shapes made by fixing the relative positions of two to eight spherical particles in five different configurations (denoted by color), packed randomly. Panels (b), (d), and (f) all show a slice through the RPP rubble pile in panel (c), but with different contact-binary core configurations (with cores in pink and matrix in gold): ellipsoids with long axes aligned along the primary body axis (EA), ellipsoids with axes parallel to the intermediate body axis (EP), and a sphere in the small lobe and ellipsoid in the large lobe with long axis parallel to the intermediate axis (SE), respectively. The envelope of the rubble pile in panel (b) looks different from panels (d) and (f) despite being embedded in the same RPP rubble pile because the slice was taken at a different angle to better display the cores. Contact-binary configurations are also investigated for the HCP and MAP cases, but since the structure and placement of the cores are identical to those in the RPP case, they are not shown here.
Paper: The Influence of Internal Structure on Physical Outcomes of the 2029 Apophis Close Approach with Earth
Authors: Joseph V. DeMartini, Derek C. Richardson, Naomi Murdoch, Raphaël F. Garcia, Nicholas C. Schmerr, Petr Scheirich, Ronald-L. Ballouz, Adriana Daca
Figure caption: Comparison of acceleration magnitudes (m s−2) over time (hr) in the body-fixed frame for a pair of particles at the endpoints of the principal axis for the simulation shown in Figure 6. The tidal acceleration for the particles is shown with the black solid line and has the same magnitude for both particles. The remaining accelerations are shown with dashed lines for one particle and dotted lines for the other. Green lines show the local gravitational accelerations that the particles feel from their positions on the surface and toward the body center of mass. Orange lines show the centrifugal accelerations felt by the particles in the body-fixed frame, and blue lines show the Euler accelerations in the same frame. Coriolis accelerations are not shown here but are on the order of 10−11 m s−2. The “period of significant tidal influence” is the time in this figure where the tidal force dominates over the centrifugal force (but remains much smaller than the local gravitational force) between 2 and ∼8 hr after the start of the simulation and centered on the time of perigee.
Paper: The Influence of Internal Structure on Physical Outcomes of the 2029 Apophis Close Approach with Earth
Authors: Joseph V. DeMartini, Derek C. Richardson, Naomi Murdoch, Raphaël F. Garcia, Nicholas C. Schmerr, Petr Scheirich, Ronald-L. Ballouz, Adriana Daca
Figure caption: Results of our measurements of axis length change over time in a single simulation from the high-resolution RPP simulation suite. The axis length changes (change in particle separations) measured for particle pairs at the endpoints of the primary body axes are colored in blue, orange, and green for the major, intermediate, and minor axes, respectively. Ten additional curves are plotted (in gray) for separation changes between randomly chosen particle pairs throughout the rubble pile, to indicate that the deformation occurs throughout the body. Curves with positive axis length change are in tension, while those with negative length changes are in compression. The time of closest approach is marked with a dashed black line and labeled “Close Approach.” In this simulation, the major axis shows the largest maximum change and is in tension, while the intermediate and minor axes are in compression.
Paper: The Influence of Internal Structure on Physical Outcomes of the 2029 Apophis Close Approach with Earth
Authors: Joseph V. DeMartini, Derek C. Richardson, Naomi Murdoch, Raphaël F. Garcia, Nicholas C. Schmerr, Petr Scheirich, Ronald-L. Ballouz, Adriana Daca
Figure caption: Diagrams showing the different single-core internal configurations with both ellipsoidal (panels (a), (c), and (e)) and spheroidal (panels (b), (d), and (f)) cores at fractions of (a, b) 25%, (c, d) 50%, and (e, f) 75% of the largest inscribed core of the 3D convex hull constructed from the particle positions. All cores are embedded in the same RPP rubble pile from Figure 4(c); rigid-aggregate cores are shown in pink, and the matrix is shown in gold. These same six single-core configurations are also investigated for the HCP and MAP cases, but those are not shown here, as the core placement is identical to those in the RPP case in these figures. Each frame contains, in the upper left corner, the label that is used to identify simulations of this type in Figures 15–17.
Paper: The Influence of Internal Structure on Physical Outcomes of the 2029 Apophis Close Approach with Earth
Authors: Joseph V. DeMartini, Derek C. Richardson, Naomi Murdoch, Raphaël F. Garcia, Nicholas C. Schmerr, Petr Scheirich, Ronald-L. Ballouz, Adriana Daca
Figure caption: A diagram showing the plane we define as the “neck” of Apophis by calculating the smallest cross-sectional area of any bisecting planes with normals less than 25° from the primary body axis of Apophis. The mesh shown in the image is taken from the vertices defined in the M. Brozović et al. (2018) radar-derived, concave shape model that assumes a bilobate (or contact-binary) structure for Apophis. The shape model has been rotated so that the normal axis of the bisecting plane (solid blue line in the center of the image) lies along the horizontal axis, and the vertical axis shows an axis perpendicular to the plane normal that is similar to the intermediate body axis direction of Apophis. The legend indicates both the point along the principal axis that was used to define the bisecting plane and the area of the cross-section polygon defined by the boundary where the plane intersects the shape model.
Paper: The Influence of Internal Structure on Physical Outcomes of the 2029 Apophis Close Approach with Earth
Authors: Joseph V. DeMartini, Derek C. Richardson, Naomi Murdoch, Raphaël F. Garcia, Nicholas C. Schmerr, Petr Scheirich, Ronald-L. Ballouz, Adriana Daca
Figure caption: The five different PKDGRAV  aggregate forms that we use in this study to examine the influence of packing with irregular particle shapes. From left to right, the forms are referred to as tetrahedra (green), four-particle rods (“rods”; yellow), planar diamonds (“diamonds”; violet), dumbbells (red), and cubes (cyan). These shapes are used for the uniform packing described in Section 2.3, and an even mixture of these shapes makes up the “mixed aggregate packing” described in the same section.
Paper: The Influence of Internal Structure on Physical Outcomes of the 2029 Apophis Close Approach with Earth
Authors: Joseph V. DeMartini, Derek C. Richardson, Naomi Murdoch, Raphaël F. Garcia, Nicholas C. Schmerr, Petr Scheirich, Ronald-L. Ballouz, Adriana Daca
Figure caption: A schematic diagram of the encounter trajectory for the simulation suite investigating different internal configurations. Axes are in units of Earth radii, and Earth itself is shown to scale in dark blue at the origin. Apophis (not to scale) appears as an orange marker at its starting position in the encounter simulations. Dark-red and dark-purple arrows indicate the directions in which the major and minor axes of Apophis point at the start of an encounter simulation where the major axis will be pointing toward Earth at perigee after one quarter turn from its initial orientation, with the intermediate axis (unmarked) pointing into the page. The direction of rotation is marked by a curved orange arrow, showing the direction of rotation of Apophis, and the motion of Apophis is marked by the solid black line, with black arrows indicating the direction of motion.
Paper: The Influence of Internal Structure on Physical Outcomes of the 2029 Apophis Close Approach with Earth
Authors: Joseph V. DeMartini, Derek C. Richardson, Naomi Murdoch, Raphaël F. Garcia, Nicholas C. Schmerr, Petr Scheirich, Ronald-L. Ballouz, Adriana Daca
Figure caption: Histogram of the maximum axis length change (in millimeters) among primary body axes across all 32 different encounter orientations tested in the high-resolution RPP simulation suite. Note that the horizontal axis uses a logarithmic scale. The median of the distribution lies at 1.7 mm, an order of magnitude larger than the similar suite of simulations with HCP in J. V. DeMartini et al. (2019). The single measurement with axis length change larger than 103 mm (1 m) is due to one of the particles along the major axis rolling by a distance close to its radius during this simulation.
Paper: Retrograde Predominance of Small Saturnian Moons Reiterates a Recent Retrograde Collisional Disruption
Authors: Edward Ashton, Brett Gladman, Mike Alexandersen, Jean-Marc Petit
Figure caption: Inverse cumulative inclination distribution of the full Norse/retrograde population (top panel) and then split up into large (>4 km) and small (<4 km) members (bottom panel). We divide the Norse group into three subgroups with red dashed lines marking the boundaries. There are two sets of short red dotted lines in each panel, one at 176﹩\mathop{.}\limits^{\unicode{x000b0}}﹩5 indicating a potential further subdivision within the Phoebe subgroup (see Section 4.4.1) and one at 163∘ indicating a minor dearth of moons within the Mundilfari subgroup (see Section 5.1).
Paper: Retrograde Predominance of Small Saturnian Moons Reiterates a Recent Retrograde Collisional Disruption
Authors: Edward Ashton, Brett Gladman, Mike Alexandersen, Jean-Marc Petit
Figure caption: On-sky plot of the two fields used for this survey relative to Saturn (gray rectangles). All measurements of 5 of the 64 new moons detected are shown (circles) along with the best-fit orbit (dashed lines). This subsample illustrates the challenges of multiyear linking. (Note that the apparent nonclosure of the orbits is due to the projected saturnocentric positions being observed from the moving Earth).
Paper: Retrograde Predominance of Small Saturnian Moons Reiterates a Recent Retrograde Collisional Disruption
Authors: Edward Ashton, Brett Gladman, Mike Alexandersen, Jean-Marc Petit
Figure caption: Rose diagram of the irregular moons of Saturn with direct orbits. Each circle represents the time-averaged inclination and semimajor axis of a moon, with the size of the circle indicating the relative size of the moon. Additionally, each moon has a line that goes from the time-averaged pericentre to the time-averaged apocentre. Yellow represents moons that belong to the Gallic group, and green represents the Inuit group. The gap between S/2004 S 24 (represented by a square instead of a circle) and the rest of the Gallic group has decreased with the inclusion of the new moons, but still remains large (see Section 4.2 for discussion).
Paper: Retrograde Predominance of Small Saturnian Moons Reiterates a Recent Retrograde Collisional Disruption
Authors: Edward Ashton, Brett Gladman, Mike Alexandersen, Jean-Marc Petit
Figure caption: Rose diagram of the retrograde Saturnian irregulars. See Figure 2’s caption. Here, red represents moons belonging to the Phoebe subgroup, magenta represents the Mundilfari subgroup, blue represents the Kari subgroup, and cyan represents low-i (<151∘) Norse members. Mundilfari is represented by a square and is a darker shade of purple, in order to distinguish the moon from the rest of the subgroup named after it. Two Phoebe subgroup members that may be outlying members of the Mundilfari subgroup are indicated with an additional inset magenta dot.
Paper: A New Global Perspective on Recent Tectonism in the Lunar Maria
Authors: C. A. Nypaver, T. R. Watters, M. E. Banks, J. D. Clark, T. Frueh
Figure caption: A global map of (A) SMR age dating locations, (B) Coulomb model locations, and (C) D/L measurement locations overlaid onto the LROC Wide Angle Camera (WAC) global mosaic (∼100 m pixel–1; M. S. Robinson et al. 2010).