adsabs/AstroCLIMB huggingface dataset:
Paper: Optical Monitoring of the Didymos–Dimorphos Asteroid System with the Danish Telescope around the DART Mission Impact
Authors: Agata Rożek, Colin Snodgrass, Uffe G. Jørgensen, Petr Pravec, Mariangela Bonavita, Markus Rabus, Elahe Khalouei, Penélope Longa-Peña, Martin J. Burgdorf, Abbie Donaldson, Daniel Gardener, Dennis Crake, Sedighe Sajadian, Valerio Bozza, Jesper Skottfelt, Martin Dominik, J. Fynbo, Tobias C. Hinse, Markus Hundertmark, Sohrab Rahvar, John Southworth, Jeremy Tregloan-Reed, Mike Kretlow, Paolo Rota, Nuno Peixinho, Michael Andersen, Flavia Amadio, Daniela Barrios-López, Nora Soledad Castillo Baeza
Figure caption:                         A sample of multiaperture light curves collected with the DK telescope, calibrated to ATLAS-RefCat2 r band. Panel (a) shows an example preimpact light curve (taken with the four fixed-angular-size apertures discussed in the main text), and panel (b) shows an example multiaperture postimpact light curve. The horizontal axis scale is in days since 00:00 UT of a given observing night. Each night is divided into “segments” corresponding to different background fields used for relative light-curve extraction. Each segment and aperture size is marked with a different set of colors and symbols. The full light-curve data set is presented in Figures A1 and A2.
Paper: Constraining the Structure under Lunar Impact Basins with Gravity
Authors: David E Smith, Sander Goossens, Gregory A Neumann, Maria T Zuber
Figure caption: The cumulative Bouguer gravity from L = 5 to 1200 shows how gravity changes with depth below the surface, highlighting the increase in signal variation approaching the surface for all basins. The Zero profile also decreases, but the magnitude is minimal compared to the basins. The dashed lines indicate what we call the “transition depth” (see also Section 3), where the maximum is followed by a decrease as the depth increases. The transition depth is the depth at which most of the observed cumulative Bouguer gravity signal at the surface originates. The accumulated spectral values are computed at the reference radius of 1738 km.
Paper: Constraining the Structure under Lunar Impact Basins with Gravity
Authors: David E Smith, Sander Goossens, Gregory A Neumann, Maria T Zuber
Figure caption: Profile of cumulative spectra from equator to 70˚S along 266˚E longitude. The profile crosses through Orientale and Mendel–Rydberg basins. The profile colors indicate the latitude range of each section: light blue is the northern end of the profile, red the central core, and dark blue the southern end of the profile. Light green and dark green show the intermediate regions between the northern and southern moats and the central core, where appropriate. Spectra show that the region north of Orientale (panel (a)) is near constant from L = 20–800 and decreases as it enters in the northern moat (panel (b)) and crosses onto the central high, increasing to a maximum and then decreasing into the southern moat and into the region between the basins (panel (c)), where the signal is again near constant. The profile crosses into the northern moat of Mendel–Rydberg (panel (d)), increases onto the basin high and through the southern moat where the spectra are largely constant, and into the region (panel (e)) to the south. Similar to the basins in Figure 6, the gravity maxima are in the L ∼ 40–50 degree range.
Paper: Constraining the Structure under Lunar Impact Basins with Gravity
Authors: David E Smith, Sander Goossens, Gregory A Neumann, Maria T Zuber
Figure caption: Bouguer slices for 5 degree bands for the Imbrium and Serenitatis basins. Each slice shows how the anomaly varies in apparent structure over each depth range and contributes to the total field of the anomaly (Figure 1b). The longitude scale is 320–40, and the latitude scale is 10N-50N; the color scale is ±20 mGal for the top two slices, ±50 mgal for the center image, and −600 to 1000 mGal for lower two slices. Quasi-circular outlines have been inserted in the figure for ease of comparison of slices and are carried through all degree ranges. The spectra are cumulative, integrated downward from the surface (L = 1200).
Paper: Constraining the Structure under Lunar Impact Basins with Gravity
Authors: David E Smith, Sander Goossens, Gregory A Neumann, Maria T Zuber
Figure caption: Profiles in latitude across four basins, Imbrium, Crisium, Smythii, and Moscoviense, showing the variation of spectra with degree L and depth (pm-km), and latitude. Each profile set crosses the northern moat, the central high, and the southern moat. The light-blue region is the northern region that includes the moat, the light-green region covers the region prior to the central core, the red region indicates the central core, the dark-green region is the edge of the core prior to the moat, and the dark-blue region includes the southern moat. Each basin shows a maximum in the L = 20–60 degree range, ∼30–80 pm-km depth. Note: all spectra begin to diverge at L ∼ 10, ∼150 pm-km, and reach an almost constant value at L ∼ 100, 17 pm-km. Thumbnail images of the gravity disturbance of each basin are shown on the right for degree ranges 6–600.
Paper: Constraining the Structure under Lunar Impact Basins with Gravity
Authors: David E Smith, Sander Goossens, Gregory A Neumann, Maria T Zuber
Figure caption: Example of relationship of spectra to horizontal slices for 5 degree bands 270–540, 109–180, 60–89, 30–59, and 6–29 and corresponding pm-km depth under Orientale and Mendel–Rydberg. The longitude scale is 230–310, latitude scale 60S–10N; the color scale is ±20 mGal for the top two slices, ±50 mgal for the center image, and −600 to 1000 mGal for the lower two slices. Also seen are the Grimaldi and Cruger basins in the upper right corner of the slices. Quasi-circular outlines have been inserted in the figure for ease of comparison of slices and are carried through all degree ranges. The spectra are cumulative, integrated downward from the surface (L = 1200).
Paper: Constraining the Structure under Lunar Impact Basins with Gravity
Authors: David E Smith, Sander Goossens, Gregory A Neumann, Maria T Zuber
Figure caption: Relationship between transition depth and basin location, diameter, crustal thickness, and anomaly magnitude. (a) Latitude; (b) longitude; (c) diameter; (d) crustal thickness; (e) anomaly magnitude; (f) anomaly magnitude vs. crustal thickness. The lines are best fits to the uniformly weighted data, including panel (b), which has amplitude and phase estimated.
Paper: Constraining the Structure under Lunar Impact Basins with Gravity
Authors: David E Smith, Sander Goossens, Gregory A Neumann, Maria T Zuber
Figure caption: Comparison of eight profiles of Bouguer (red), gravity from topography (blue), and free-air gravity (green). The Bouguer profiles and the free-air gravity profile corrected for topography are invariably smother than the free-air and show how significant the topography can be on the free-air gravity field at most wavelengths. We note the smooth nature of all spectra of the four nearside basins compared to the variations seen in the farside basins, most likely due to the large topographic variations in the highlands. Nevertheless, the resulting Bouguer is smooth for L < 800 (∼3 pm-km).
Paper: Constraining the Structure under Lunar Impact Basins with Gravity
Authors: David E Smith, Sander Goossens, Gregory A Neumann, Maria T Zuber
Figure caption: Four examples of gravity signal spectra for L = 900–1200, a region that we expect to contain significant data noise that manifests itself in different forms. The charts for (a) Korolev and (b) Dirichlet–Jackson suggest possible short-wavelength variations, while the charts for (c) Apollo and (d) Humorum show long-wavelength trends.
Paper: Constraining the Structure under Lunar Impact Basins with Gravity
Authors: David E Smith, Sander Goossens, Gregory A Neumann, Maria T Zuber
Figure caption: Correlation of free-air gravity (FA) with topography (black) and Bouguer (B) gravity with topography (red). Vertical dashed lines delimit the range of degrees over which gravity is highly correlated with topography. The plot indicates that at degree 900 (<2 pm-km) the FA gravity and Bouguer gravity are both uncorrelated with topography. The upper axis shows the pm-km, and λ, km, the surface resolution.
Paper: Constraining the Structure under Lunar Impact Basins with Gravity
Authors: David E Smith, Sander Goossens, Gregory A Neumann, Maria T Zuber
Figure caption: Planviews of SPA projected from the center of the basin showing eight slices though the basin center. In all slices the value at the center is zero or near zero, consistent with the individual spectrum in Figure 2. The maps are in stereographic projection centered on 190°E, 54°S, spanning a radius of 40°.
Paper: Constraining the Structure under Lunar Impact Basins with Gravity
Authors: David E Smith, Sander Goossens, Gregory A Neumann, Maria T Zuber
Figure caption: Hemispheric slices through the NH and SH. The figures show the gravity signal at 3–6, 10–16, 29–55, and 150–493 pm-km. The maps are stereographic projections centered on each pole and extend to the equator.
Paper: The Increasingly Strange Polarimetric Behavior of the Barbarian Asteroids
Authors: Joseph R. Masiero, Maxime Devogèle, Isabella Macias, Joahan Castaneda Jaimes, Alberto Cellino
Figure caption: Polarization phase curves for the six Barbarian asteroids we observed in the near-infrared with WIRC+Pol (J and H bands). Other polarization measurements for wavelengths plotted are drawn from the literature (Bendjoya et al. 2022; Lupishko 2022). Phase function fits for any bandpass that had more than three observations are shown as dashed lines with colors matching those used to identify the data points.
Paper: The Increasingly Strange Polarimetric Behavior of the Barbarian Asteroids
Authors: Joseph R. Masiero, Maxime Devogèle, Isabella Macias, Joahan Castaneda Jaimes, Alberto Cellino
Figure caption: Left: measured WIRC+Pol scattering angle θ  r  compared to the predicted scattering angle based on orbital geometry for all asteroids with polarization measurements ∣P∣ > 1 for the J (pink pentagons) and H (black triangles) bands. Right: deviation in scattering angle (predicted—measured) compared to the predicted scattering angle. The mean of all values in each band is shown by the dashed lines of the same color as the points, which overlap at 7.°8 for both bands.
Paper: The Increasingly Strange Polarimetric Behavior of the Barbarian Asteroids
Authors: Joseph R. Masiero, Maxime Devogèle, Isabella Macias, Joahan Castaneda Jaimes, Alberto Cellino
Figure caption: The combined polarization phase curves for five Barbarian asteroids. J- and H- band measurements are from WIRC+Pol and presented here, while other bands are drawn from the literature. Our observations of (402) Chloe are not included here as it follows a noticeably different behavior at visible wavelengths.
Paper: Mineralogical Characterization and Phase Angle Study of Two Binary Near-Earth Asteroids, Potential Targets for NASA’s Janus Mission
Authors: Lucille Le Corre, Juan A. Sanchez, Vishnu Reddy, Adam Battle, David C. Cantillo, Benjamin Sharkey, Robert Jedicke, Daniel J. Scheeres
Figure caption: Visible and NIR spectrum of (175706) 1996 FG3. The NIR spectrum obtained on 2022 April 15 has been combined with the visible spectrum obtained by Binzel et al. (2001). Also shown are the spectrum of the C2ung carbonaceous chondrite Y-86789 (RELAB sample ID c1mp10) and the spectrum of the CM2 carbonaceous chondrite Murchison heated at 1000°C (RELAB sample ID ncmb64g). The grain sizes of the meteorite samples are indicated. The spectra have been offset for clarity.
Paper: Mineralogical Characterization and Phase Angle Study of Two Binary Near-Earth Asteroids, Potential Targets for NASA’s Janus Mission
Authors: Lucille Le Corre, Juan A. Sanchez, Vishnu Reddy, Adam Battle, David C. Cantillo, Benjamin Sharkey, Robert Jedicke, Daniel J. Scheeres
Figure caption: NIR spectrum of (35107) 1991 VH (gray circles) normalized to unity at 1.5 μm with prominent absorption bands due to minerals olivine and pyroxene.
Paper: Mineralogical Characterization and Phase Angle Study of Two Binary Near-Earth Asteroids, Potential Targets for NASA’s Janus Mission
Authors: Lucille Le Corre, Juan A. Sanchez, Vishnu Reddy, Adam Battle, David C. Cantillo, Benjamin Sharkey, Robert Jedicke, Daniel J. Scheeres
Figure caption: Spectral slopes calculated from a linear fit to the spectra between 1.0 and 1.75 μm vs. phase angle for (175706) 1996 FG3.
Paper: Mineralogical Characterization and Phase Angle Study of Two Binary Near-Earth Asteroids, Potential Targets for NASA’s Janus Mission
Authors: Lucille Le Corre, Juan A. Sanchez, Vishnu Reddy, Adam Battle, David C. Cantillo, Benjamin Sharkey, Robert Jedicke, Daniel J. Scheeres
Figure caption: Molar percent of fayalite (Fa) vs. ferrosilite (Fs) for (35107) 1991 VH. For comparison, calculated values for asteroid Itokawa from Sanchez et al. (2020) are also shown. Measured values for LL (squares), L (triangles), and H (circles) ordinary chondrites from Nakamura et al. (2011) are also included. The error bars in the upper right corner correspond to the uncertainties derived by Sanchez et al. (2020), 2.0 mol% for Fa and 1.4 mol% for Fs. Figure adapted from Nakamura et al. (2011).
Paper: Mineralogical Characterization and Phase Angle Study of Two Binary Near-Earth Asteroids, Potential Targets for NASA’s Janus Mission
Authors: Lucille Le Corre, Juan A. Sanchez, Vishnu Reddy, Adam Battle, David C. Cantillo, Benjamin Sharkey, Robert Jedicke, Daniel J. Scheeres
Figure caption: Band I center vs. BAR for (35107) 1991 VH. Values measured for LL, L, and H ordinary chondrites from Sanchez et al. (2020) are depicted as squares, triangles, and circles, respectively. Regions corresponding to the S(II), S(III), and S(IV) subgroups of Gaffey et al. (1993) are shown. OC indicates the ordinary chondrites region, which is the same as the S(IV) subgroup region. The dashed line indicates the location of the olivine–orthopyroxene mixing line of Cloutis et al. (1986).
Paper: Phase Curves of Kuiper Belt Objects, Centaurs, and Jupiter-family Comets from the ATLAS Survey
Authors: Matthew M. Dobson, Megan E. Schwamb, Susan D. Benecchi, Anne J. Verbiscer, Alan Fitzsimmons, Luke J. Shingles, Larry Denneau, A. N. Heinze, Ken W. Smith, John L. Tonry, Henry Weiland, David. R. Young
Figure caption: ATLAS difference (left) and reduced (right) images of Echeclus during its observed cometary outburst. Red crosshairs denote Echeclus’s position on the images. Upper: 2017 December 29 19:31 UTC (MJD 58117.313716) ATLAS o-filter images, with fan-shaped coma clearly visible (detected from our short-outburst search algorithm). Middle: 2018 January 17 18:09 UTC (MJD 58136.256515) ATLAS o-filter images, with fan-shaped coma clearly visible (detected from our longer-term, lower-level activity search algorithm). Lower: 2018 March 5 UTC 17:09 (MJD 58183.215153) ATLAS o-filter images, showing Echeclus to appear fuzzy compared to background stars, indicating residual coma (detected from our short-outburst search algorithm).
Paper: Phase Curves of Kuiper Belt Objects, Centaurs, and Jupiter-family Comets from the ATLAS Survey
Authors: Matthew M. Dobson, Megan E. Schwamb, Susan D. Benecchi, Anne J. Verbiscer, Alan Fitzsimmons, Luke J. Shingles, Larry Denneau, A. N. Heinze, Ken W. Smith, John L. Tonry, Henry Weiland, David. R. Young
Figure caption: Collage of ATLAS difference (left) and reduced (right) images of, in descending order, Pluto (2019 July 4 19:05 UTC, c filter), Pluto (2020 October 6 14:34 UTC, o filter), Chiron (2016 December 21 15:17 UTC, c filter), Quaoar (2021 March 21 18:44 UTC, o filter), and Echeclus (2021-1-2 21:56 UTC, o filter). Red crosshairs denote positions of objects in images. In all images, the objects lie close to often poorly subtracted background stars.
Paper: Phase Curves of Kuiper Belt Objects, Centaurs, and Jupiter-family Comets from the ATLAS Survey
Authors: Matthew M. Dobson, Megan E. Schwamb, Susan D. Benecchi, Anne J. Verbiscer, Alan Fitzsimmons, Luke J. Shingles, Larry Denneau, A. N. Heinze, Ken W. Smith, John L. Tonry, Henry Weiland, David. R. Young
Figure caption: PSF FWHM analysis for 2021 June 23 (MJD 59388) ATLAS images of (2060) Chiron. Upper row: 100 × 100 pixel inset of 1000 × 1000 pixel reduced ATLAS images centered on (2060) Chiron. Lower row: histograms of the FWHM of all background stars in each 1000 × 1000 pixel ATLAS image, with the median stellar FWHM (dashed magenta vertical line) and (2060) Chiron FWHM (solid green vertical line) plotted for reference. In all images, the FWHM of (2060) Chiron remains consistent with the histogram distribution of the FWHM of background stars, with no significant extension.
Paper: Phase Curves of Kuiper Belt Objects, Centaurs, and Jupiter-family Comets from the ATLAS Survey
Authors: Matthew M. Dobson, Megan E. Schwamb, Susan D. Benecchi, Anne J. Verbiscer, Alan Fitzsimmons, Luke J. Shingles, Larry Denneau, A. N. Heinze, Ken W. Smith, John L. Tonry, Henry Weiland, David. R. Young
Figure caption: PSF FWHM analysis for 2018 March 6 (MJD 58183) ATLAS images of (60558) Echeclus. Upper row: 100 × 100 pixel inset of 1000 × 1000 pixel reduced ATLAS images centered on Echeclus. Lower row: histograms of the FWHM of all background stars in each 1000 × 1000 pixel ATLAS image, with the median stellar FWHM (dashed magenta vertical line) and Echeclus FWHM (solid green vertical line) plotted for reference. In all images, Echeclus displays significant PSF extension.
Paper: Phase Curves of Kuiper Belt Objects, Centaurs, and Jupiter-family Comets from the ATLAS Survey
Authors: Matthew M. Dobson, Megan E. Schwamb, Susan D. Benecchi, Anne J. Verbiscer, Alan Fitzsimmons, Luke J. Shingles, Larry Denneau, A. N. Heinze, Ken W. Smith, John L. Tonry, Henry Weiland, David. R. Young
Figure caption: Plots of phase-angle-corrected reduced magnitude vs. MJD in ATLAS c (turquoise, upper) and o (orange, upper) and phase curves of reduced magnitude vs. phase angle in ATLAS c (turquoise, lower) and o (orange, lower) for (501585) 2014 QA43. Red points denote observations taken from nights with ≥3 observations of which 75% are brighter than 2σ from the sigma-clipped object’s median magnitude. Magenta points denote observations within a 30 days bin whose median magnitude lies 0.2 mag and 1 standard deviation brighter than the object’s sigma-clipped median magnitude.
Paper: Phase Curves of Kuiper Belt Objects, Centaurs, and Jupiter-family Comets from the ATLAS Survey
Authors: Matthew M. Dobson, Megan E. Schwamb, Susan D. Benecchi, Anne J. Verbiscer, Alan Fitzsimmons, Luke J. Shingles, Larry Denneau, A. N. Heinze, Ken W. Smith, John L. Tonry, Henry Weiland, David. R. Young
Figure caption: Plots of phase-angle-corrected reduced magnitude vs. MJD in ATLAS c (turquoise, upper) and o (orange, upper) and phase curves of reduced magnitude vs. phase angle in ATLAS c (turquoise, lower) and o (orange, lower) for (2060) Chiron. Red points denote observations taken from nights with ≥3 observations of which 75% are brighter than 2σ from the object’s median sigma-clipped magnitude.
Paper: Phase Curves of Kuiper Belt Objects, Centaurs, and Jupiter-family Comets from the ATLAS Survey
Authors: Matthew M. Dobson, Megan E. Schwamb, Susan D. Benecchi, Anne J. Verbiscer, Alan Fitzsimmons, Luke J. Shingles, Larry Denneau, A. N. Heinze, Ken W. Smith, John L. Tonry, Henry Weiland, David. R. Young
Figure caption: 2021 June 17 23:32 UTC (MJD 59383.480799) ATLAS difference image (left) and reduced image (right) of Chiron during its 2021–2022 active epoch, taken in ATLAS o filter. Red crosshairs denote Chiron’s position on the images. Chiron’s signal remains point-like from visual inspection.
Paper: Phase Curves of Kuiper Belt Objects, Centaurs, and Jupiter-family Comets from the ATLAS Survey
Authors: Matthew M. Dobson, Megan E. Schwamb, Susan D. Benecchi, Anne J. Verbiscer, Alan Fitzsimmons, Luke J. Shingles, Larry Denneau, A. N. Heinze, Ken W. Smith, John L. Tonry, Henry Weiland, David. R. Young
Figure caption: Plots of phase-angle-corrected reduced magnitude vs. MJD in ATLAS c (turquoise, upper) and o (orange, upper) and phase curves of reduced magnitude vs. phase angle in ATLAS c (turquoise, lower) and o (orange, lower) for (134340) Pluto, also corrected for rotational modulation. Red points denote observations taken from nights with ≥3 observations of which 75% are brighter than 2σ from the sigma-clipped object’s median magnitude.
Paper: Phase Curves of Kuiper Belt Objects, Centaurs, and Jupiter-family Comets from the ATLAS Survey
Authors: Matthew M. Dobson, Megan E. Schwamb, Susan D. Benecchi, Anne J. Verbiscer, Alan Fitzsimmons, Luke J. Shingles, Larry Denneau, A. N. Heinze, Ken W. Smith, John L. Tonry, Henry Weiland, David. R. Young
Figure caption: Plots of phase-angle-corrected reduced magnitude vs. MJD in ATLAS c (turquoise, upper) and o (orange, upper) and phase curves of reduced magnitude vs. phase angle in ATLAS c (turquoise, lower) and o (orange, lower) for (50000) Quaoar, also corrected for rotational modulation. Red points denote observations taken from nights with ≥3 observations of which 75% are brighter than 2σ from the object’s sigma-clipped median magnitude.
Paper: Phase Curves of Kuiper Belt Objects, Centaurs, and Jupiter-family Comets from the ATLAS Survey
Authors: Matthew M. Dobson, Megan E. Schwamb, Susan D. Benecchi, Anne J. Verbiscer, Alan Fitzsimmons, Luke J. Shingles, Larry Denneau, A. N. Heinze, Ken W. Smith, John L. Tonry, Henry Weiland, David. R. Young
Figure caption:  G 1,G 2 KDE distributions of taxonomic complexes as mapped by Mahlke et al. (2021) in c and o ATLAS filters, with G 1 and G 2 parameters of Hidalgo (circle), Narcissus (square), and 2014 QA43 (triangle) phase curves overplotted. Contours mark KDE levels at which 68.3% (1σ), 95% (2σ), and 99.7% (3σ) of values are encompassed. Uncertainties for Hidalgo data points are smaller than the plot symbol.
Paper: Phase Curves of Kuiper Belt Objects, Centaurs, and Jupiter-family Comets from the ATLAS Survey
Authors: Matthew M. Dobson, Megan E. Schwamb, Susan D. Benecchi, Anne J. Verbiscer, Alan Fitzsimmons, Luke J. Shingles, Larry Denneau, A. N. Heinze, Ken W. Smith, John L. Tonry, Henry Weiland, David. R. Young
Figure caption: PSF FWHM analysis for 2020 November 11 (MJD 59164) ATLAS images of (501585) 2014 QA43. Upper row: 100 × 100 pixel inset of 1000 × 1000 pixel reduced ATLAS images centered on (501585) 2014 QA43. Lower row: histograms of the FWHM of all background stars in each 1000 × 1000 pixel ATLAS image, with the median stellar FWHM (dashed magenta vertical line) and (501585) 2014 QA43 FWHM (solid green vertical line) plotted for reference. The PSF of (501585) 2014 QA43 remains consistent with the histogram distribution of the FWHM of background stars, with no significant extension.
Paper: A Geologic Map of Vesta Produced Using a Hybrid Method for Incorporating Spectroscopic and Morphologic Data
Authors: R. Aileen Yingst, Scott C. Mest, W. Brent Garry, David A. Williams, Daniel C. Berman, Tracy K. P. Gregg
Figure caption: (a). Crater size–frequency distribution and randomness plots calculated from LDM for Marcia crater. Older age likely indicates a surface that predated the impact. Younger age likely indicates crater impact age. (b). Crater size–frequency distribution and randomness plots calculated from ADM for the Marcia crater. Older age likely indicates a surface that predated the impact. Younger age likely indicates crater impact age.
Paper: A Geologic Map of Vesta Produced Using a Hybrid Method for Incorporating Spectroscopic and Morphologic Data
Authors: R. Aileen Yingst, Scott C. Mest, W. Brent Garry, David A. Williams, Daniel C. Berman, Tracy K. P. Gregg
Figure caption: (a). Crater size–frequency distribution and randomness plots calculated from LDM for Rheasilvia ridge and trough terrain (rtR). Older age likely indicates unit formation age. Younger age likely indicates a period of resurfacing. (b). Crater size–frequency distribution and randomness plots calculated from ADM for Rheasilvia ridge and trough terrain (rtR). Older age likely indicates unit formation age. Younger age likely indicates a period of resurfacing.