Search

Your search keyword '"Rozitis, B"' showing total 214 results
Start Over Author "Rozitis, B"
214 results on '"Rozitis, B"'

1. Physical modelling of near-Earth asteroid (23187) 2000 PN9 with ground-based optical and radar observations

Author

Dover, L., Lowry, S. C., Rożek, A., Rozitis, B., Jackson, S. L., Zegmott, T., Krugly, Yu. N., Belskaya, I. N., Fitzsimmons, A., Green, S. F., Snodgrass, C., Weissman, P. R., Brozović, M., Benner, L. A. M., Busch, M. W., Ayvazian, V. R., Chiorny, V., Inasaridze, R. Ya., Krugov, M., Mykhailova, S., Reva, I., and Hibbert, J.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

We present a physical model and spin-state analysis of the potentially hazardous asteroid (23187) 2000 PN9. As part of a long-term campaign to make direct detections of the YORP effect, we collected optical lightcurves of the asteroid between 2006 and 2020. These observations were combined with planetary radar data to develop a detailed shape model which was used to search for YORP acceleration. We report that 2000 PN9 is a relatively large top-shaped body with a sidereal rotation period of 2.53216$\pm$0.00015 h. Although we find no evidence for rotational acceleration, YORP torques smaller than $\sim$10$^{-8}$$\,\rm rad/day^{2}$ cannot be ruled out. It is likely that 2000 PN9 is a YORP-evolved object, and may be an example of YORP equilibrium or self limitation., Comment: Accepted for publication in Monthly Notices of the Royal Astronomical Society. Main paper: 15 pages, 12 figures. Appendix: 9 pages, 8 figures

Published
2023

2. Detection of the YORP Effect on the contact-binary (68346) 2001 KZ66 from combined radar and optical observations

Author

Zegmott, Tarik J., Lowry, S. C., Rożek, A., Rozitis, B., Nolan, M. C., Howell, E. S., Green, S. F., Snodgrass, C., Fitzsimmons, A., and Weissman, P. R.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

The YORP effect is a small thermal-radiation torque experienced by small asteroids, and is considered to be crucial in their physical and dynamical evolution. It is important to understand this effect by providing measurements of YORP for a range of asteroid types to facilitate the development of a theoretical framework. We are conducting a long-term observational study on a selection of near-Earth asteroids to support this. We focus here on (68346) 2001 KZ66, for which we obtained both optical and radar observations spanning a decade. This allowed us to perform a comprehensive analysis of the asteroid's rotational evolution. Furthermore, radar observations from the Arecibo Observatory enabled us to generate a detailed shape model. We determined that (68346) is a retrograde rotator with its pole near the southern ecliptic pole, within a $ 15^\circ$ radius of longitude $ 170^\circ$ and latitude $ -85^\circ$. By combining our radar-derived shape model with the optical light curves we developed a refined solution to fit all available data, which required a YORP strength of $ (8.43\pm0.69)\times10^{-8} \rm~rad ~day^{-2} $. (68346) has a distinct bifurcated shape comprising a large ellipsoidal component joined by a sharp neckline to a smaller non-ellipsoidal component. This object likely formed from either the gentle merging of a binary system, or from the deformation of a rubble pile due to YORP spin-up. The shape exists in a stable configuration close to its minimum in topographic variation, where regolith is unlikely to migrate from areas of higher potential., Comment: To be published in the Monthly Notices of the Royal Astronomical Society (MNRAS). 19 pages, 14 figures

Published
2021
Full Text
View/download PDF

4. Fine-regolith production on asteroids controlled by rock porosity

Author

Cambioni, S., Delbo, M., Poggiali, G., Avdellidou, C., Ryan, A. J., Deshapriya, J. D. P., Asphaug, E., Ballouz, R.-L., Barucci, M. A., Bennett, C. A., Bottke, W. F., Brucato, J. R., Burke, K. N., Cloutis, E., DellaGiustina, D. N., Emery, J. P., Rozitis, B., Walsh, K. J., and Lauretta, D. S.

Published
2021
Full Text
View/download PDF

6. THERMAP: a mid-infrared spectro-imager for space missions to small bodies in the inner solar system

Author

Groussin, O., Licandro, J., Helbert, J., Reynaud, J. -L., Levacher, P., García-Talavera, M. Reyes, Alí-Lagoa, V., Blanc, P. -E., Brageot, E., Davidsson, B., Delbó, M., Deleuze, M., Delsanti, A., Garcia, J. J. Diaz, Dohlen, K., Ferrand, D., Green, S., Jorda, L., Álvarez, E. Joven, Knollenberg, J., Kührt, E., Lamy, P., Lellouch, E., Merrer, J. Le, Marty, B., Mas, G., Rossin, C., Rozitis, B., Sunshine, J., Vernazza, P., and Vives, S.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

We present THERMAP, a mid-infrared (8-16 {\mu}m) spectro-imager for space missions to small bodies in the inner solar system, developed in the framework of the MarcoPolo-R asteroid sample return mission. THERMAP is very well suited to characterize the surface thermal environment of a NEO and to map its surface composition. The instrument has two channels, one for imaging and one for spectroscopy: it is both a thermal camera with full 2D imaging capabilities and a slit spectrometer. THERMAP takes advantage of the recent technological developments of uncooled microbolometers detectors, sensitive in the mid-infrared spectral range. THERMAP can acquire thermal images (8-18 {\mu}m) of the surface and perform absolute temperature measurements with a precision better than 3.5 K above 200 K. THERMAP can acquire mid-infrared spectra (8-16 {\mu}m) of the surface with a spectral resolution {\Delta}{\lambda} of 0.3 {\mu}m. For surface temperatures above 350 K, spectra have a signal-to-noise ratio >60 in the spectral range 9-13 {\mu}m where most emission features occur., Comment: 21 pages, 12 figures, 3 tables; Experimental Astronomy: in press

Published
2015
Full Text
View/download PDF

7. Granular Shear Flow in Varying Gravitational Environments

Author

Murdoch, N., Rozitis, B., Green, S. F., de Lophem, T-L, Michel, P., and Losert, W.

Subjects
Condensed Matter - Soft Condensed Matter, Astrophysics - Earth and Planetary Astrophysics, Physics - Geophysics
Abstract

Despite their very low surface gravities, asteroids exhibit a number of different geological processes involving granular matter. Understanding the response of this granular material subject to external forces in microgravity conditions is vital to the design of a successful asteroid sub-surface sampling mechanism, and in the interpretation of the fascinating geology on an asteroid. We have designed and flown a Taylor-Couette shear cell to investigate granular flow due to rotational shear forces under the conditions of parabolic flight microgravity. The experiments occur under weak compression. First, we present the technical details of the experimental design with particular emphasis on how the equipment has been specifically designed for the parabolic flight environment. Then, we investigate how a steady state granular flow induced by rotational shear forces differs in varying gravitational environments. We find that the effect of constant shearing on the granular material, in a direction perpendicular to the effective acceleration, does not seem to be strongly influenced by gravity. This means that shear bands can form in the presence of a weak gravitational field just as on Earth., Comment: 18 pages, 10 figures

Published
2013
Full Text
View/download PDF

8. Granular Convection in Microgravity

Author

Murdoch, N., Rozitis, B., Nordstrom, K., Green, S. F., Michel, P., de Lophem, T. -L., and Losert, W.

Subjects
Condensed Matter - Soft Condensed Matter, Astrophysics - Earth and Planetary Astrophysics, Physics - Geophysics
Abstract

We investigate the role of gravity on convection in a dense granular shear flow. Using a microgravity modified Taylor-Couette shear cell under the conditions of parabolic flight microgravity, we demonstrate experimentally that secondary, convective-like flows in a sheared granular material are close to zero in microgravity and enhanced under high-gravity conditions, though the primary flow fields are unaffected by gravity. We suggest that gravity tunes the frictional particle-particle and particle-wall interactions, which have been proposed to drive the secondary flow. In addition, the degree of plastic deformation increases with increasing gravitational forces, supporting the notion that friction is the ultimate cause., Comment: 13 pages, 6 figures

Published
2013
Full Text
View/download PDF

9. Simulating regoliths in microgravity

Author

Murdoch, N., Rozitis, B., Green, S. F., Michel, P., de Lophem, T-L., and Losert, W.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Physics - Geophysics
Abstract

Despite their very low surface gravities, the surfaces of asteroids and comets are covered by granular materials - regolith - that can range from a fine dust to a gravel-like structure of varying depths. Understanding the dynamics of granular materials is, therefore, vital for the interpretation of the surface geology of these small bodies and is also critical for the design and/or operations of any device planned to interact with their surfaces. We present the first measurements of transient weakening of granular material after shear reversal in microgravity as well as a summary of experimental results recently published in other journals, which may have important implications for small-body surfaces. Our results suggest that the force contact network within a granular material may be weaker in microgravity, although the influence of any change in the contact network is felt by the granular material over much larger distances. This could mean that small body surfaces are even more unstable than previously imagined. However, our results also indicate that the consequences of, e.g., a meteorite impact or a spacecraft landing, may be very different depending on the impact angle and location, and depending on the prior history of the small body surface., Comment: 11 pages, 8 figures

Published
2013
Full Text
View/download PDF

10. Orbit and bulk density of the OSIRIS-REx target Asteroid (101955) Bennu

Author

Chesley, SR, Farnocchia, D, Nolan, MC, Vokrouhlický, D, Chodas, PW, Milani, A, Spoto, F, Rozitis, B, Benner, LAM, Bottke, WF, Busch, MW, Emery, JP, Howell, ES, Lauretta, DS, Margot, JL, and Taylor, PA

Subjects
Near-Earth objects, Orbit determination, Celestial mechanics, Asteroids, dynamics, Radar observations, astro-ph.EP, Astronomy & Astrophysics, Astronomical and Space Sciences, Geochemistry, Geophysics
Abstract

The target asteroid of the OSIRIS-REx asteroid sample return mission, (101955) Bennu (formerly 1999 RQ36), is a half-kilometer near-Earth asteroid with an extraordinarily well constrained orbit. An extensive data set of optical astrometry from 1999 to 2013 and high-quality radar delay measurements to Bennu in 1999, 2005, and 2011 reveal the action of the Yarkovsky effect, with a mean semimajor axis drift rate da / dt = (- 19.0 ± 0.1) × 10 - 4 au/Myr or 284 ± 1.5 m/year. The accuracy of this result depends critically on the fidelity of the observational and dynamical model. As an example, neglecting the relativistic perturbations of the Earth during close approaches affects the orbit with 3σ significance in da / dt. The orbital deviations from purely gravitational dynamics allow us to deduce the acceleration of the Yarkovsky effect, while the known physical characterization of Bennu allows us to independently model the force due to thermal emissions. The combination of these two analyses yields a bulk density of ρ = 1260 ± 70 kg/m3, which indicates a macroporosity in the range 40 ± 10 % for the bulk densities of likely analog meteorites, suggesting a rubble-pile internal structure. The associated mass estimate is (7.8 ± 0.9) × 1010 kg and GM = 5.2 ± 0.6 m3 / s2.Bennu's Earth close approaches are deterministic over the interval 1654-2135, beyond which the predictions are statistical in nature. In particular, the 2135 close approach is likely within the lunar distance and leads to strong scattering and numerous potential impacts in subsequent years, from 2175 to 2196. The highest individual impact probability is 9.5 × 10 - 5 in 2196, and the cumulative impact probability is 3.7 × 10 - 4, leading to a cumulative Palermo Scale of -1.70. © 2014 Elsevier Inc.

Published
2014

11. Physical modelling of near-Earth asteroid (23187) 2000 PN9 with ground-based optical and radar observations

Author

Dover, L, primary, Lowry, S C, additional, Rożek, A, additional, Rozitis, B, additional, Jackson, S L, additional, Zegmott, T, additional, Krugly, Yu N, additional, Belskaya, I N, additional, Fitzsimmons, A, additional, Green, S F, additional, Snodgrass, C, additional, Weissman, P R, additional, Brozović, M, additional, Benner, L A M, additional, Busch, M W, additional, Ayvazian, V R, additional, Chiorny, V, additional, Inasaridze, R Ya, additional, Krugov, M, additional, Mykhailova, S, additional, Reva, I, additional, and Hibbert, J, additional

Published
2023
Full Text
View/download PDF

12. The dynamic geophysical environment of (101955) Bennu based on OSIRIS-REx measurements

Author

Scheeres, D. J., McMahon, J. W., French, A. S., Brack, D. N., Chesley, S. R., Farnocchia, D., Takahashi, Y., Leonard, J. M., Geeraert, J., Page, B., Antreasian, P., Getzandanner, K., Rowlands, D., Mazarico, E. M., Small, J., Highsmith, D. E., Moreau, M., Emery, J. P., Rozitis, B., Hirabayashi, M., Sánchez, P., Van wal, S., Tricarico, P., Ballouz, R.-L., Johnson, C. L., Al Asad, M. M., Susorney, H. C. M., Barnouin, O. S., Daly, M. G., Seabrook, J. A., Gaskell, R. W., Palmer, E. E., Weirich, J. R., Walsh, K. J., Jawin, E. R., Bierhaus, E. B., Michel, P., Bottke, W. F., Nolan, M. C., Connolly, Jr, H. C., Lauretta, D. S., and The OSIRIS-REx Team

Published
2019
Full Text
View/download PDF

13. Evidence for widespread hydrated minerals on asteroid (101955) Bennu

Author

Hamilton, V. E., Simon, A. A., Christensen, P. R., Reuter, D. C., Clark, B. E., Barucci, M. A., Bowles, N. E., Boynton, W. V., Brucato, J. R., Cloutis, E. A., Connolly, Jr, H. C., Donaldson Hanna, K. L., Emery, J. P., Enos, H. L., Fornasier, S., Haberle, C. W., Hanna, R. D., Howell, E. S., Kaplan, H. H., Keller, L. P., Lantz, C., Li, J.-Y., Lim, L. F., McCoy, T. J., Merlin, F., Nolan, M. C., Praet, A., Rozitis, B., Sandford, S. A., Schrader, D. L., Thomas, C. A., Zou, X.-D., Lauretta, D. S., and the OSIRIS-REx Team

Published
2019
Full Text
View/download PDF

14. Properties of rubble-pile asteroid (101955) Bennu from OSIRIS-REx imaging and thermal analysis

Author

DellaGiustina, D. N., Emery, J. P., Golish, D. R., Rozitis, B., Bennett, C. A., Burke, K. N., Ballouz, R.-L., Becker, K. J., Christensen, P. R., Drouet d’Aubigny, C. Y., Hamilton, V. E., Reuter, D. C., Rizk, B., Simon, A. A., Asphaug, E., Bandfield, J. L., Barnouin, O. S., Barucci, M. A., Bierhaus, E. B., Binzel, R. P., Bottke, W. F., Bowles, N. E., Campins, H., Clark, B. C., Clark, B. E., Connolly, Jr., H. C., Daly, M. G., Leon, J. de, Delbo’, M., Deshapriya, J. D. P., Elder, C. M., Fornasier, S., Hergenrother, C. W., Howell, E. S., Jawin, E. R., Kaplan, H. H., Kareta, T. R., Le Corre, L., Li, J.-Y., Licandro, J., Lim, L. F., Michel, P., Molaro, J., Nolan, M. C., Pajola, M., Popescu, M., Garcia, J. L. Rizos, Ryan, A., Schwartz, S. R., Shultz, N., Siegler, M. A., Smith, P. H., Tatsumi, E., Thomas, C. A., Walsh, K. J., Wolner, C. W. V., Zou, X.-D., Lauretta, D. S., and The OSIRIS-REx Team

Published
2019
Full Text
View/download PDF

15. Episodes of Particle Ejection from the Surface of the Active Asteroid (101955) Bennu

Author

Lauretta, D. S, Hergenrother, C. W, Chesley, S. R, Leonard, J. M, Pelgrift, J. Y, Adam, C. D, Asad, M. Al, Antreasian, P. G, Ballouz, R.-L, Becker, K. J, Bennett, C. A, Bos, B. J, Bottke, W. F, Brozovi, M, Campins, H, Jr, H. C. Connolly, Daly, M. G, Davis, A. B, León, J. de, DellaGiustina, D. N, d’Aubigny, C. Y. Drouet, Dworkin, J. P, Emery, J. P, Farnocchia, D, Glavin, D. P, Golish, D. R, Hartzell, C. M, Jacobson, R. A, Jawin, E. R, Jenniskens, P, Jr, J. N. Kidd, Lessac-Chenen, E. J, Li, J.-Y, Libourel, G, Licandro, J, Liounis, A. J, Maleszewski, C. K, Manzoni, C, May, B, McCarthy, L. K, McMahon, J. W, Michel, P, Molaro, J. L, Moreau, M. C, Nelson, D. S, Jr, W. M. Owen, Rizk, B, Roper, H. L, Rozitis, B, Sahr, E. M, Scheeres, D. J, Seabrook, J. A, Selznick, S. H, Takahashi, Y, Thuillet, F, Tricarico, P, Vokrouhlick, D, and Wolner, C. W. V

Subjects
Lunar And Planetary Science And Exploration
Abstract

Active asteroids are those that show evidence of ongoing mass loss. We report repeated instances of particle ejection from the surface of (101955) Bennu, demonstrating that it is an active asteroid. The ejection events were imaged by the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer) spacecraft. For the three largest observed events, we estimated the ejected particle velocities and sizes, event times, source regions, and energies. We also determined the trajectories and photometric properties of several gravitationally bound particles that orbited temporarily in the Bennu environment. We consider multiple hypotheses for the mechanisms that lead to particle ejection for the largest events, including rotational disruption, electrostatic lofting, ice sublimation, phyllosilicate dehydration, meteoroid impacts, thermal stress fracturing, and secondary impacts.

Published
2019
Full Text
View/download PDF

16. The effect of aspect changes on Near-Earth Asteroid phase curves

Author

Jackson, S. L., Rozitis, B., Dover, L. R., Green, S. F., Kolb, U. C., Andrews, A. E., and Lowry, S. C.

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Space and Planetary Science, Physics::Space Physics, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics - Earth and Planetary Astrophysics
Abstract

Phase curves of asteroids are typically considered to depend solely on the scattering properties of airless particulate surfaces and the size of the object being studied. In this study, we demonstrate the additional dependence of phase curves on object shape, rotation pole orientation, and viewing geometry over an apparition. Variations in the phase curve of near-Earth asteroid (159402) 1999 AP10 over its apparition from July 2020 - January 2021 are verified to be due to aspect changes over the apparition. This is achieved through shape modelling of the asteroid and simulation of the phase curve over the apparition. We present simulations of asteroid phase curves over a range of geometries to understand the potential magnitude of this aspect effect, and under which circumstances it can begin to dominate in the phase curves. This dependence on aspect may introduce significant additional uncertainty in the properties derived from phase curve data. We provide and demonstrate software code to estimate the aspect-related uncertainty in near-Earth asteroid phase curves through simulation and model fitting of a randomly generated sample of ellipsoidal asteroid models over the observed viewing geometry. We demonstrate how ignoring this effect may lead to misleading interpretations of the data and underestimation of uncertainties in further studies, such as those in the infrared that use phase curve derived parameters when fitting physical properties of an asteroid., Accepted for publication in Monthly Notices of the Royal Astronomical Society. 14 pages, 11 figures, 5 tables

Published
2022

17. THERMAP: a mid-infrared spectro-imager for space missions to small bodies in the inner solar system

Author

Groussin, O., Licandro, J., Helbert, J., Reynaud, J. L., Levacher, P., Reyes García-Talavera, M., Alí-Lagoa, V., Blanc, P. E., Brageot, E., Davidsson, B., Delbó, M., Deleuze, M., Delsanti, A., Diaz Garcia, J. J., Dohlen, K., Ferrand, D., Green, S. F., Jorda, L., Joven Álvarez, E., Knollenberg, J., Kührt, E., Lamy, P., Lellouch, E., Le Merrer, J., Marty, B., Mas, G., Rossin, C., Rozitis, B., Sunshine, J., Vernazza, P., and Vives, S.

Published
2016
Full Text
View/download PDF

18. Spacecraft sample collection and subsurface excavation of asteroid (101955) Bennu

Author

Lauretta, D. S., primary, Adam, C. D., additional, Allen, A. J., additional, Ballouz, R.-L., additional, Barnouin, O. S., additional, Becker, K. J., additional, Becker, T., additional, Bennett, C. A., additional, Bierhaus, E. B., additional, Bos, B. J., additional, Burns, R. D., additional, Campins, H., additional, Cho, Y., additional, Christensen, P. R., additional, Church, E. C. A., additional, Clark, B. E., additional, Connolly, H. C., additional, Daly, M. G., additional, DellaGiustina, D. N., additional, Drouet d’Aubigny, C. Y., additional, Emery, J. P., additional, Enos, H. L., additional, Kasper, S. Freund, additional, Garvin, J. B., additional, Getzandanner, K., additional, Golish, D. R., additional, Hamilton, V. E., additional, Hergenrother, C. W., additional, Kaplan, H. H., additional, Keller, L. P., additional, Lessac-Chenen, E. J., additional, Liounis, A. J., additional, Ma, H., additional, McCarthy, L. K., additional, Miller, B. D., additional, Moreau, M. C., additional, Morota, T., additional, Nelson, D. S., additional, Nolau, J. O., additional, Olds, R., additional, Pajola, M., additional, Pelgrift, J. Y., additional, Polit, A. T., additional, Ravine, M. A., additional, Reuter, D. C., additional, Rizk, B., additional, Rozitis, B., additional, Ryan, A. J., additional, Sahr, E. M., additional, Sakatani, N., additional, Seabrook, J. A., additional, Selznick, S. H., additional, Skeen, M. A., additional, Simon, A. A., additional, Sugita, S., additional, Walsh, K. J., additional, Westermann, M. M., additional, Wolner, C. W. V., additional, and Yumoto, K., additional

Published
2022
Full Text
View/download PDF

21. Raising the Albedo of 2010 GY6: Fitting ATPM to Wise Data

Author

Wooden, D. H, Rozitis, B. D, Jefferson, J. D, Nelson, T. W, and Dotson, J. L

Subjects
Lunar And Planetary Science And Exploration
Abstract

Near-Earth Asteroid 462775 (2010 GY6) is in the Apollo orbit-family with a 1.46 year orbital period. 2010 GY6 was measured by WISE and fitted with NEATM, yielding NEATM model parameters of D=1.1 km, pv=0.028 and eta=2.3.The NEATM-derived geometric albedo of 2010 GY6 is lower than the surface of comet 67P/C-G. The eta value is considerably higher than typical for its phase angle of 33 deg, indicating a cooler surface due to non-zero thermal inertia and/or surface roughness are important. If the thermal inertia and surface roughness are constrained by fitting the Advanced Thermophysical Model (ATPM) to the WISE data, what would the resulting geometric albedo? We find pv=0.06-0.08, in the same range as B- or C-type NEAs like Bennu or JU3.

Published
2017

24. Craters, boulders and regolith of (101955) Bennu indicative of an old and dynamic surface

Author

Walsh, KJ, Jawin, ER, Ballouz, R-L, Barnouin, OS, Bierhaus, EB, Jr, CHC, Molaro, JL, McCoy, TJ, Delbo', M, Hartzell, CM, Pajola, M, Schwartz, SR, Trang, D, Asphaug, E, Becker, KJ, Beddingfield, CB, Bennett, CA, Bottke, WF, Burke, KN, Clark, BC, Daly, MG, Dellagiustina, DN, Dworkin, JP, Elder, CM, Golish, DR, Hildebrand, AR, Malhotra, R, Marshall, J, Michel, P, Nolan, MC, Perry, ME, Rizk, B, Ryan, A, Sandford, SA, Scheeres, DJ, Susorney, HCM, Thuillet, F, Lauretta, DS, Highsmith, DE, Small, J, Vokrouhlicky, D, Bowles, NE, Brown, E, Hanna, KLD, Warren, T, Brunet, C, Chicoine, RA, Desjardins, S, Gaudreau, D, Haltigin, T, Millington-Veloza, S, Rubi, A, Aponte, J, Gorius, N, Lunsford, A, Allen, B, Grindlay, J, Guevel, D, Hoak, D, Hong, J, Schrader, DL, Bayron, J, Golubov, O, Sanchez, P, Stromberg, J, Hirabayashi, M, Oliver, S, Rascon, M, Harch, A, Joseph, J, Squyres, S, Richardson, D, Emery, JP, McGraw, L, Ghent, R, Binzel, RP, Asad, MM, Johnson, CL, Philpott, L, Cloutis, EA, Hanna, RD, Ciceri, F, Ibrahim, E-M, Breitenfeld, L, Glotch, T, Rogers, AD, Clark, BE, Ferrone, S, Thomas, CA, Campins, H, Fernandez, Y, Chang, W, Cheuvront, A, Tachibana, S, Yurimoto, H, Brucato, JR, Poggiali, G, Dotto, E, Epifani, EM, Crombie, MK, Lantz, C, Izawa, MRM, De Leon, J, Licandro, J, Garcia, JLR, Clemett, S, Thomas-Keprta, K, Van Wal, S, Yoshikawa, M, Bellerose, J, Bhaskaran, S, Boyles, C, Chesley, SR, Farnocchia, D, Harbison, A, Kennedy, B, Knight, A, Martinez-Vlasoff, N, Mastrodemos, N, McElrath, T, Owen, W, Park, R, Rush, B, Swanson, L, Takahashi, Y, Velez, D, Yetter, K, Thayer, C, Adam, C, Antreasian, P, Bauman, J, Bryan, C, Carcich, B, Corvin, M, Geeraert, J, Hoffman, J, Leonard, JM, Lessac-Chenen, E, Levine, A, McAdams, J, McCarthy, L, Nelson, D, Page, B, Pelgrift, J, Sahr, E, Stakkestad, K, Stanbridge, D, Wibben, D, Williams, B, Williams, K, Wolff, P, Hayne, P, Kubitschek, D, Barucci, MA, Deshapriya, JDP, Fornasier, S, Fulchignoni, M, Hasselmann, P, Merlin, F, Praet, A, Billett, O, Boggs, A, Buck, B, Carlson-Kelly, S, Cerna, J, Chaffin, K, Church, E, Coltrin, M, Daly, J, Deguzman, A, Dubisher, R, Eckart, D, Ellis, D, Falkenstern, P, Fisher, A, Fisher, ME, Fleming, P, Fortney, K, Francis, S, Freund, S, Gonzales, S, Haas, P, Hasten, A, Hauf, D, Hilbert, A, Howell, D, Jaen, F, Jayakody, N, Jenkins, M, Johnson, K, Lefevre, M, Ma, H, Mario, C, Martin, K, May, C, McGee, M, Miller, B, Miller, C, Miller, G, Mirfakhrai, A, Muhle, E, Norman, C, Olds, R, Parish, C, Ryle, M, Schmitzer, M, Sherman, P, Skeen, M, Susak, M, Sutter, B, Tran, Q, Welch, C, Witherspoon, R, Wood, J, Zareski, J, Arvizu-Jakubicki, M, Audi, E, Bandrowski, R, Becker, TL, Bendall, S, Bloomenthal, H, Blum, D, Boynton, WV, Brodbeck, J, Chojnacki, M, Colpo, A, Contreras, J, Cutts, J, D'Aubigny, CYD, Dean, D, Diallo, B, Drinnon, D, Drozd, K, Enos, HL, Enos, R, Fellows, C, Ferro, T, Fisher, MR, Fitzgibbon, G, Fitzgibbon, M, Forelli, J, Forrester, T, Galinsky, I, Garcia, R, Gardner, A, Habib, N, Hamara, D, Hammond, D, Hanley, K, Harshman, K, Hergenrother, CW, Herzog, K, Hill, D, Hoekenga, C, Hooven, S, Howell, ES, Huettner, E, Janakus, A, Jones, J, Kareta, TR, Kidd, J, Kingsbury, K, Balram-Knutson, SS, Koelbel, L, Kreiner, J, Lambert, D, Lewin, C, Lovelace, B, Loveridge, M, Lujan, M, Maleszewski, CK, Marchese, K, McDonough, E, Mogk, N, Morrison, V, Morton, E, Munoz, R, Nelson, J, Padilla, J, Pennington, R, Polit, A, Ramos, N, Reddy, V, Riehl, M, Roper, HL, Salazar, S, Selznick, S, Shultz, N, Smith, PH, Stewart, S, Sutton, S, Swindle, T, Tang, YH, Westermann, M, Wolner, CWV, Worden, D, Zega, T, Zeszut, Z, Bjurstrom, A, Bloomquist, L, Dickinson, C, Keates, E, Liang, J, Nifo, V, Taylor, A, Teti, F, Caplinger, M, Bowles, H, Carter, S, Dickenshied, S, Doerres, D, Fisher, T, Hagee, W, Hill, J, Miner, M, Noss, D, Piacentine, N, Smith, M, Toland, A, Wren, P, Bernacki, M, Munoz, DP, Watanabe, S-I, Aqueche, A, Ashman, B, Barker, M, Bartels, A, Berry, K, Bos, B, Burns, R, Calloway, A, Carpenter, R, Castro, N, Cosentino, R, Donaldson, J, Cook, JE, Emr, C, Everett, D, Fennell, D, Fleshman, K, Folta, D, Gallagher, D, Garvin, J, Getzandanner, K, Glavin, D, Hull, S, Hyde, K, Ido, H, Ingegneri, A, Jones, N, Kaotira, P, Lim, LF, Liounis, A, Lorentson, C, Lorenz, D, Lyzhoft, J, Mazarico, EM, Mink, R, Moore, W, Moreau, M, Mullen, S, Nagy, J, Neumann, G, Nuth, J, Poland, D, Reuter, DC, Rhoads, L, Rieger, S, Rowlands, D, Sallitt, D, Scroggins, A, Shaw, G, Simon, AA, Swenson, J, Vasudeva, P, Wasser, M, Zellar, R, Grossman, J, Johnston, G, Morris, M, Wendel, J, Burton, A, Keller, LP, McNamara, L, Messenger, S, Nakamura-Messenger, K, Nguyen, A, Righter, K, Queen, E, Bellamy, K, Dill, K, Gardner, S, Giuntini, M, Key, B, Kissell, J, Patterson, D, Vaughan, D, Wright, B, Gaskell, RW, Le Corre, L, Li, J-Y, Palmer, EE, Siegler, MA, Tricarico, P, Weirich, JR, Zou, X-D, Ireland, T, Tait, K, Bland, P, Anwar, S, Bojorquez-Murphy, N, Christensen, PR, Haberle, CW, Mehall, G, Rios, K, Franchi, I, Rozitis, B, Brack, DN, French, AS, McMahon, JW, Russell, S, Killgore, M, Hamilton, VE, Kaplan, HH, Bandfield, JL, Chodas, M, Lambert, M, Masterson, RA, Freemantle, J, Seabrook, JA, Craft, K, Daly, RT, Ernst, C, Espiritu, RC, Holdridge, M, Jones, M, Nair, AH, Nguyen, L, Peachey, J, Plescia, J, Roberts, JH, Steele, R, Turner, R, Backer, J, Edmundson, K, Mapel, J, Milazzo, M, Sides, S, Manzoni, C, May, B, Delbo, M, Libourel, G, Marty, B, Team, O-R, Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, Laboratoire de Géophysique Interne et Tectonophysique (LGIT), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Laboratoire Central des Ponts et Chaussées (LCPC)-Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), ASU School of Earth and Space Exploration (SESE), Arizona State University [Tempe] (ASU), IHU-LIRYC, Université Bordeaux Segalen - Bordeaux 2-CHU Bordeaux [Bordeaux], NASA Goddard Space Flight Center (GSFC), National Dairy Research Institute, SETI Institute, Institute of Northern Engineering, 455 Duckering Bldg, Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Centre de Mise en Forme des Matériaux (CEMEF), Centre National de la Recherche Scientifique (CNRS)-PSL Research University (PSL)-MINES ParisTech - École nationale supérieure des mines de Paris, Institut des Sciences de la Terre (ISTerre), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), and ANR-15-IDEX-0001,UCA JEDI,Idex UCA JEDI(2015)

Subjects
Near-Earth object, 010504 meteorology & atmospheric sciences, Mass movement, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Geomorphology, 010502 geochemistry & geophysics, 01 natural sciences, Billion years, Regolith, Astrobiology, [SPI]Engineering Sciences [physics], Asteroids comets and Kuiper belt, Impact crater, Asteroid, General Earth and Planetary Sciences, Asteroid belt, Early solar system, Geology, 0105 earth and related environmental sciences
Abstract

著者人数: 38名ほか (The OSIRIS-REx Team: 所属. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS): Van wal, S; 吉川, 真; 渡邊, 誠一郎), Number of authors: 38 and The OSIRIS-REx Team (Affiliation. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS): Van wal, S; Yoshikawa, Makoto; Watanabe, Sei-icihro), Accepted: 2019-02-11, 資料番号: SA1190038000

Published
2019
Full Text
View/download PDF

25. Regional Photometric Modeling of Asteroid (101955) Bennu

Author

Golish, D. R., primary, Li, J.-Y., additional, Clark, B. E., additional, DellaGiustina, D. N., additional, Zou, X.-D., additional, Rizos, J. L., additional, Hasselmann, P. H., additional, Bennett, C. A., additional, Fornasier, S., additional, Drouet d’Aubigny, C., additional, Rizk, B., additional, Daly, M. G., additional, Barnouin, O. S., additional, Seabrook, J. A., additional, Philpott, L., additional, Al Asad, M. M., additional, Johnson, C. L., additional, Rozitis, B., additional, Ryan, A. J., additional, Emery, J. P., additional, and Lauretta, D. S., additional

Published
2021
Full Text
View/download PDF

26. effect of aspect changes on Near-Earth Asteroid phase curves.

Author

Jackson, S L, Rozitis, B, Dover, L R, Green, S F, Kolb, U C, Andrews, A E, and Lowry, S C

Subjects
*NEAR-earth asteroids, *CURVES, *SMALL solar system bodies, *ASTEROIDS
Abstract

Phase curves of asteroids are typically considered to depend solely on the scattering properties of airless particulate surfaces and the size of the object being studied. In this study, we demonstrate the additional dependence of phase curves on object shape, rotation pole orientation, and viewing geometry over an apparition. Variations in the phase curve of near-Earth asteroid (159402) 1999 AP10 over its apparition from 2020 July to 2021 January are verified to be due to aspect changes over the apparition. This is achieved through shape modelling of the asteroid and simulation of the phase curve over the apparition. We present simulations of asteroid phase curves over a range of geometries to understand the potential magnitude of this aspect effect, and under which circumstances it can begin to dominate in the phase curves. This dependence on aspect may introduce significant additional uncertainty in the properties derived from phase-curve data. We provide and demonstrate software code to estimate the aspect-related uncertainty in near-Earth asteroid phase curves through simulation and model fitting of a randomly generated sample of ellipsoidal asteroid models over the observed viewing geometry. We demonstrate how ignoring this effect may lead to misleading interpretations of the data and underestimation of uncertainties in further studies, such as those in the infrared that use phase curve derived parameters when fitting physical properties of an asteroid. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

27. Asteroid (101955) Bennu’s weak boulders and thermally anomalous equator

Author

Pino Muñoz, Daniel, Rozitis, B., Ryan, A., Emery, J., Christensen, P., Hamilton, V., Simon, A., Reuter, D., Al Asad, M., Ballouz, R.-L., Bandfield, J., Barnouin, O., Bennett, C., Bernacki, M., Burke, K., Cambioni, S., Clark, B., Daly, M., Delbo, M., DellaGiustina, D., Elder, C., Hanna, R., Haberle, C., Howell, E., Golish, D., Jawin, E., Kaplan, H., Lim, L., Molaro, J., Munoz, D. Pino, Nolan, M., Rizk, B., Siegler, M., Susorney, H., Walsh, K., Lauretta, D., MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL), Centre de Mise en Forme des Matériaux (CEMEF), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, Mass movement, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Astronomy, media_common.quotation_subject, Population, Equator, Inertia, 01 natural sciences, Astrobiology, 0103 physical sciences, education, 010303 astronomy & astrophysics, Research Articles, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, media_common, education.field_of_study, Multidisciplinary, SciAdv r-articles, [CHIM.MATE]Chemical Sciences/Material chemistry, Albedo, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, Meteorite, Atmospheric entry, Asteroid, [SDU]Sciences of the Universe [physics], Physics::Space Physics, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Astrophysics::Earth and Planetary Astrophysics, Planetary Science, Geology, Research Article
Abstract

Heterogeneous thermal properties of Bennu are due primarily to spatial mixing of two boulder types with differing strengths., Thermal inertia and surface roughness are proxies for the physical characteristics of planetary surfaces. Global maps of these two properties distinguish the boulder population on near-Earth asteroid (NEA) (101955) Bennu into two types that differ in strength, and both have lower thermal inertia than expected for boulders and meteorites. Neither has strongly temperature-dependent thermal properties. The weaker boulder type probably would not survive atmospheric entry and thus may not be represented in the meteorite collection. The maps also show a high–thermal inertia band at Bennu’s equator, which might be explained by processes such as compaction or strength sorting during mass movement, but these explanations are not wholly consistent with other data. Our findings imply that other C-complex NEAs likely have boulders similar to those on Bennu rather than finer-particulate regoliths. A tentative correlation between albedo and thermal inertia of C-complex NEAs may be due to relative abundances of boulder types.

Published
2020
Full Text
View/download PDF

28. Variations in color and reflectance on the surface of asteroid (101955) Bennu

Author

DellaGiustina, D. N., primary, Burke, K. N., additional, Walsh, K. J., additional, Smith, P. H., additional, Golish, D. R., additional, Bierhaus, E. B., additional, Ballouz, R.-L., additional, Becker, T. L., additional, Campins, H., additional, Tatsumi, E., additional, Yumoto, K., additional, Sugita, S., additional, Deshapriya, J. D. Prasanna, additional, Cloutis, E. A., additional, Clark, B. E., additional, Hendrix, A. R., additional, Sen, A., additional, Al Asad, M. M., additional, Daly, M. G., additional, Applin, D. M., additional, Avdellidou, C., additional, Barucci, M. A., additional, Becker, K. J., additional, Bennett, C. A., additional, Bottke, W. F., additional, Brodbeck, J. I., additional, Connolly, H. C., additional, Delbo, M., additional, de Leon, J., additional, Drouet d’Aubigny, C. Y., additional, Edmundson, K. L., additional, Fornasier, S., additional, Hamilton, V. E., additional, Hasselmann, P. H., additional, Hergenrother, C. W., additional, Howell, E. S., additional, Jawin, E. R., additional, Kaplan, H. H., additional, Le Corre, L., additional, Lim, L. F., additional, Li, J. Y., additional, Michel, P., additional, Molaro, J. L., additional, Nolan, M. C., additional, Nolau, J., additional, Pajola, M., additional, Parkinson, A., additional, Popescu, M., additional, Porter, N. A., additional, Rizk, B., additional, Rizos, J. L., additional, Ryan, A. J., additional, Rozitis, B., additional, Shultz, N. K., additional, Simon, A. A., additional, Trang, D., additional, Van Auken, R. B., additional, Wolner, C. W. V., additional, and Lauretta, D. S., additional

Published
2020
Full Text
View/download PDF

29. Hemispherical differences in the shape and topography of asteroid (101955) Bennu

Author

Daly, M. G., primary, Barnouin, O. S., additional, Seabrook, J. A., additional, Roberts, J., additional, Dickinson, C., additional, Walsh, K. J., additional, Jawin, E. R., additional, Palmer, E. E., additional, Gaskell, R., additional, Weirich, J., additional, Haltigin, T., additional, Gaudreau, D., additional, Brunet, C., additional, Cunningham, G., additional, Michel, P., additional, Zhang, Y., additional, Ballouz, R.-L., additional, Neumann, G., additional, Perry, M. E., additional, Philpott, L., additional, Al Asad, M. M., additional, Johnson, C. L., additional, Adam, C. D., additional, Leonard, J. M., additional, Geeraert, J. L., additional, Getzandanner, K., additional, Nolan, M. C., additional, Daly, R. T., additional, Bierhaus, E. B., additional, Mazarico, E., additional, Rozitis, B., additional, Ryan, A. J., additional, DellaGiustina, D. N., additional, Rizk, B., additional, Susorney, H. C. M., additional, Enos, H. L., additional, and Lauretta, D. S., additional

Published
2020
Full Text
View/download PDF

30. Asteroid (101955) Bennu’s weak boulders and thermally anomalous equator

Author

Rozitis, B., primary, Ryan, A. J., additional, Emery, J. P., additional, Christensen, P. R., additional, Hamilton, V. E., additional, Simon, A. A., additional, Reuter, D. C., additional, Al Asad, M., additional, Ballouz, R.-L., additional, Bandfield, J. L., additional, Barnouin, O. S., additional, Bennett, C. A., additional, Bernacki, M., additional, Burke, K. N., additional, Cambioni, S., additional, Clark, B. E., additional, Daly, M. G., additional, Delbo, M., additional, DellaGiustina, D. N., additional, Elder, C. M., additional, Hanna, R. D., additional, Haberle, C. W., additional, Howell, E. S., additional, Golish, D. R., additional, Jawin, E. R., additional, Kaplan, H. H., additional, Lim, L. F., additional, Molaro, J. L., additional, Munoz, D. Pino, additional, Nolan, M. C., additional, Rizk, B., additional, Siegler, M. A., additional, Susorney, H. C. M., additional, Walsh, K. J., additional, and Lauretta, D. S., additional

Published
2020
Full Text
View/download PDF

31. Heterogeneous mass distribution of the rubble-pile asteroid (101955) Bennu

Author

Scheeres, D. J., primary, French, A. S., additional, Tricarico, P., additional, Chesley, S. R., additional, Takahashi, Y., additional, Farnocchia, D., additional, McMahon, J. W., additional, Brack, D. N., additional, Davis, A. B., additional, Ballouz, R.-L., additional, Jawin, E. R., additional, Rozitis, B., additional, Emery, J. P., additional, Ryan, A. J., additional, Park, R. S., additional, Rush, B. P., additional, Mastrodemos, N., additional, Kennedy, B. M., additional, Bellerose, J., additional, Lubey, D. P., additional, Velez, D., additional, Vaughan, A. T., additional, Leonard, J. M., additional, Geeraert, J., additional, Page, B., additional, Antreasian, P., additional, Mazarico, E., additional, Getzandanner, K., additional, Rowlands, D., additional, Moreau, M. C., additional, Small, J., additional, Highsmith, D. E., additional, Goossens, S., additional, Palmer, E. E., additional, Weirich, J. R., additional, Gaskell, R. W., additional, Barnouin, O. S., additional, Daly, M. G., additional, Seabrook, J. A., additional, Al Asad, M. M., additional, Philpott, L. C., additional, Johnson, C. L., additional, Hartzell, C. M., additional, Hamilton, V. E., additional, Michel, P., additional, Walsh, K. J., additional, Nolan, M. C., additional, and Lauretta, D. S., additional

Published
2020
Full Text
View/download PDF

32. Trajectory Estimation for Particles Observed in the Vicinity of (101955) Bennu

Author

Chesley, S. R., primary, French, A. S., additional, Davis, A. B., additional, Jacobson, R. A., additional, Brozović, M., additional, Farnocchia, D., additional, Selznick, S., additional, Liounis, A. J., additional, Hergenrother, C. W., additional, Moreau, M. C., additional, Pelgrift, J., additional, Lessac‐Chenen, E., additional, Molaro, J. L., additional, Park, R. S., additional, Rozitis, B., additional, Scheeres, D. J., additional, Takahashi, Y., additional, Vokrouhlický, D., additional, Wolner, C. W. V., additional, Adam, C., additional, Bos, B. J., additional, Christensen, E. J., additional, Emery, J. P., additional, Leonard, J. M., additional, McMahon, J. W., additional, Nolan, M. C., additional, Shelly, F. C., additional, and Lauretta, D. S., additional

Published
2020
Full Text
View/download PDF

34. Particle Ejection Contributions to the Rotational Acceleration and Orbit Evolution of Asteroid (101955) Bennu

Author

Scheeres, D. J., primary, McMahon, J. W., additional, Brack, D. N., additional, French, A. S., additional, Chesley, S. R., additional, Farnocchia, D., additional, Vokrouhlický, D., additional, Ballouz, R.‐L., additional, Emery, J. P., additional, Rozitis, B., additional, Nolan, M. C., additional, Hergenrother, C. W., additional, and Lauretta, D. S., additional

Published
2020
Full Text
View/download PDF

35. The operational environment and rotational acceleration of asteroid (101955) Bennu from OSIRIS-REx observations

Author

Hergenrother, CW, Maleszewski, CK, Nolan, MC, Li, J-Y, d'Aubigny, CYD, Shelly, FC, Howell, ES, Kareta, TR, Izawa, MRM, Barucci, MA, Bierhaus, EB, Campins, H, Chesley, SR, Clark, BE, Christensen, EJ, DellaGiustina, DN, Fornasier, S, Golish, DR, Hartzell, CM, Rizk, B, Scheeres, DJ, Smith, PH, Zou, X-D, Lauretta, DS, Highsmith, DE, Small, J, Vokrouhlicky, D, Bowles, NE, Brown, E, Hanna, KLD, Warren, T, Brunet, C, Chicoine, RA, Desjardins, S, Gaudreau, D, Haltigin, T, Millington-Veloza, S, Rubi, A, Aponte, J, Gorius, N, Lunsford, A, Allen, B, Grindlay, J, Guevel, D, Hoak, D, Hong, J, Schrader, DL, Bayron, J, Golubov, O, Sanchez, P, Stromberg, J, Hirabayashi, M, Oliver, S, Rascon, M, Harch, A, Joseph, J, Squyres, S, Richardson, D, Emery, JP, McGraw, L, Ghent, R, Binzel, RP, Al Asad, MM, Johnson, CL, Philpott, L, Susorney, HCM, Cloutis, EA, Hanna, RD, Connolly, HC, Ciceri, F, Hildebrand, AR, Ibrahim, E-M, Breitenfeld, L, Glotch, T, Rogers, AD, Ferrone, S, Thomas, CA, Fernandez, Y, Chang, W, Cheuvront, A, Trang, D, Tachibana, S, Yurimoto, H, Brucato, JR, Poggiali, G, Pajola, M, Dotto, E, Epifani, EM, Crombie, MK, Lantz, C, de Leon, J, Licandro, J, Rizos Garcia, JL, Clemett, S, Thomas-Keprta, K, Van Wal, S, Yoshikawa, M, Bellerose, J, Bhaskaran, S, Boyles, C, Elder, CM, Farnocchia, D, Harbison, A, Kennedy, B, Knight, A, Martinez-Vlasoff, N, Mastrodemos, N, McElrath, T, Owen, W, Park, R, Rush, B, Swanson, L, Takahashi, Y, Velez, D, Yetter, K, Thayer, C, Adam, C, Antreasian, P, Bauman, J, Bryan, C, Carcich, B, Corvin, M, Geeraert, J, Hoffman, J, Leonard, JM, Lessac-Chenen, E, Levine, A, McAdams, J, McCarthy, L, Nelson, D, Page, B, Pelgrift, J, Sahr, E, Stakkestad, K, Stanbridge, D, Wibben, D, Williams, B, Williams, K, Wolff, P, Hayne, P, Kubitschek, D, Deshapriya, JDP, Fulchignoni, M, Hasselmann, P, Merlin, F, Praet, A, Billett, O, Boggs, A, Buck, B, Carlson-Kelly, S, Cerna, J, Chaffin, K, Church, E, Coltrin, M, Daly, J, Deguzman, A, Dubisher, R, Eckart, D, Ellis, D, Falkenstern, P, Fisher, A, Fisher, ME, Fleming, P, Fortney, K, Francis, S, Freund, S, Gonzales, S, Haas, P, Hasten, A, Hauf, D, Hilbert, A, Howell, D, Jaen, F, Jayakody, N, Jenkins, M, Johnson, K, Lefevre, M, Ma, H, Mario, C, Martin, K, May, C, McGee, M, Miller, B, Miller, C, Miller, G, Mirfakhrai, A, Muhle, E, Norman, C, Olds, R, Parish, C, Ryle, M, Schmitzer, M, Sherman, P, Skeen, M, Susak, M, Sutter, B, Tran, Q, Welch, C, Witherspoon, R, Wood, J, Zareski, J, Arvizu-Jakubicki, M, Asphaug, E, Audi, E, Ballouz, R-L, Bandrowski, R, Becker, KJ, Becker, TL, Bendall, S, Bennett, CA, Bloomenthal, H, Blum, D, Boynton, W, Brodbeck, J, Burke, KN, Chojnacki, M, Colpo, A, Contreras, J, Cutts, J, Dean, D, Diallo, B, Drinnon, D, Drozd, K, Enos, HL, Enos, R, Fellows, C, Ferro, T, Fisher, MR, Fitzgibbon, G, Fitzgibbon, M, Forelli, J, Forrester, T, Galinsky, I, Garcia, R, Gardner, A, Habib, N, Hamara, D, Hammond, D, Hanley, K, Harshman, K, Herzog, K, Hill, D, Hoekenga, C, Hooven, S, Huettner, E, Janakus, A, Jones, J, Kidd, J, Kingsbury, K, Balram-Knutson, SS, Koelbel, L, Kreiner, J, Lambert, D, Lewin, C, Lovelace, B, Loveridge, M, Lujan, M, Malhotra, R, Marchese, K, McDonough, E, Mogk, N, Morrison, V, Morton, E, Munoz, R, Nelson, J, Padilla, J, Pennington, R, Polit, A, Ramos, N, Reddy, V, Riehl, M, Roper, HL, Salazar, S, Schwartz, SR, Selznick, S, Shultz, N, Stewart, S, Sutton, S, Swindle, T, Tang, YH, Westermann, M, Wolner, CW, Worden, D, Zega, T, Zeszut, Z, Bjurstrom, A, Bloomquist, L, Dickinson, C, Keates, E, Liang, J, Nifo, V, Taylor, A, Teti, F, Caplinger, M, Bowles, H, Carter, S, Dickenshied, S, Doerres, D, Fisher, T, Hagee, W, Hill, J, Miner, M, Noss, D, Piacentine, N, Smith, M, Toland, A, Wren, P, Bernacki, M, Munoz, DP, Watanabe, S, Sandford, SA, Aqueche, A, Ashman, B, Barker, M, Bartels, A, Berry, K, Bos, B, Burns, R, Calloway, A, Carpenter, R, Castro, N, Cosentino, R, Donaldson, J, Dworkin, JP, Cook, JE, Emr, C, Everett, D, Fennell, D, Fleshman, K, Folta, D, Gallagher, D, Garvin, J, Getzandanner, K, Glavin, D, Hull, S, Hyde, K, Ido, H, Ingegneri, A, Jones, N, Kaotira, P, Lim, LF, Liounis, A, Lorentson, C, Lorenz, D, Lyzhoft, J, Mazarico, EM, Mink, R, Moore, W, Moreau, M, Mullen, S, Nagy, J, Neumann, G, Nuth, J, Poland, D, Reuter, DC, Rhoads, L, Rieger, S, Rowlands, D, Sallitt, D, Scroggins, A, Shaw, G, Simon, AA, Swenson, J, Vasudeva, P, Wasser, M, Zellar, R, Grossman, J, Johnston, G, Morris, M, Wendel, J, Burton, A, Keller, LP, McNamara, L, Messenger, S, Nakamura-Messenger, K, Nguyen, A, Righter, K, Queen, E, Bellamy, K, Dill, K, Gardner, S, Giuntini, M, Key, B, Kissell, J, Patterson, D, Vaughan, D, Wright, B, Gaskell, RW, Le Corre, L, Molaro, JL, Palmer, EE, Siegler, MA, Tricarico, P, Weirich, JR, Ireland, T, Tait, K, Bland, P, Anwar, S, Bojorquez-Murphy, N, Christensen, PR, Haberle, CW, Mehall, G, Rios, K, Franchi, I, Rozitis, B, Beddingfield, CB, Marshall, J, Brack, DN, French, AS, McMahon, JW, Jawin, ER, McCoy, TJ, Russell, S, Killgore, M, Bottke, WF, Hamilton, VE, Kaplan, HH, Walsh, KJ, Bandfield, JL, Clark, BC, Chodas, M, Lambert, M, Masterson, RA, Daly, MG, Freemantle, J, Seabrook, JA, Barnouin, OS, Craft, K, Daly, RT, Ernst, C, Espiritu, RC, Holdridge, M, Jones, M, Nair, AH, Nguyen, L, Peachey, J, Perry, ME, Plescia, J, Roberts, JH, Steele, R, Turner, R, Backer, J, Edmundson, K, Mapel, J, Milazzo, M, Sides, S, Manzoni, C, May, B, Delbo, M, Libourel, G, Michel, P, Ryan, A, Thuillet, F, Marty, B, Hergenrother, CW, Maleszewski, CK, Nolan, MC, Li, J-Y, d'Aubigny, CYD, Shelly, FC, Howell, ES, Kareta, TR, Izawa, MRM, Barucci, MA, Bierhaus, EB, Campins, H, Chesley, SR, Clark, BE, Christensen, EJ, DellaGiustina, DN, Fornasier, S, Golish, DR, Hartzell, CM, Rizk, B, Scheeres, DJ, Smith, PH, Zou, X-D, Lauretta, DS, Highsmith, DE, Small, J, Vokrouhlicky, D, Bowles, NE, Brown, E, Hanna, KLD, Warren, T, Brunet, C, Chicoine, RA, Desjardins, S, Gaudreau, D, Haltigin, T, Millington-Veloza, S, Rubi, A, Aponte, J, Gorius, N, Lunsford, A, Allen, B, Grindlay, J, Guevel, D, Hoak, D, Hong, J, Schrader, DL, Bayron, J, Golubov, O, Sanchez, P, Stromberg, J, Hirabayashi, M, Oliver, S, Rascon, M, Harch, A, Joseph, J, Squyres, S, Richardson, D, Emery, JP, McGraw, L, Ghent, R, Binzel, RP, Al Asad, MM, Johnson, CL, Philpott, L, Susorney, HCM, Cloutis, EA, Hanna, RD, Connolly, HC, Ciceri, F, Hildebrand, AR, Ibrahim, E-M, Breitenfeld, L, Glotch, T, Rogers, AD, Ferrone, S, Thomas, CA, Fernandez, Y, Chang, W, Cheuvront, A, Trang, D, Tachibana, S, Yurimoto, H, Brucato, JR, Poggiali, G, Pajola, M, Dotto, E, Epifani, EM, Crombie, MK, Lantz, C, de Leon, J, Licandro, J, Rizos Garcia, JL, Clemett, S, Thomas-Keprta, K, Van Wal, S, Yoshikawa, M, Bellerose, J, Bhaskaran, S, Boyles, C, Elder, CM, Farnocchia, D, Harbison, A, Kennedy, B, Knight, A, Martinez-Vlasoff, N, Mastrodemos, N, McElrath, T, Owen, W, Park, R, Rush, B, Swanson, L, Takahashi, Y, Velez, D, Yetter, K, Thayer, C, Adam, C, Antreasian, P, Bauman, J, Bryan, C, Carcich, B, Corvin, M, Geeraert, J, Hoffman, J, Leonard, JM, Lessac-Chenen, E, Levine, A, McAdams, J, McCarthy, L, Nelson, D, Page, B, Pelgrift, J, Sahr, E, Stakkestad, K, Stanbridge, D, Wibben, D, Williams, B, Williams, K, Wolff, P, Hayne, P, Kubitschek, D, Deshapriya, JDP, Fulchignoni, M, Hasselmann, P, Merlin, F, Praet, A, Billett, O, Boggs, A, Buck, B, Carlson-Kelly, S, Cerna, J, Chaffin, K, Church, E, Coltrin, M, Daly, J, Deguzman, A, Dubisher, R, Eckart, D, Ellis, D, Falkenstern, P, Fisher, A, Fisher, ME, Fleming, P, Fortney, K, Francis, S, Freund, S, Gonzales, S, Haas, P, Hasten, A, Hauf, D, Hilbert, A, Howell, D, Jaen, F, Jayakody, N, Jenkins, M, Johnson, K, Lefevre, M, Ma, H, Mario, C, Martin, K, May, C, McGee, M, Miller, B, Miller, C, Miller, G, Mirfakhrai, A, Muhle, E, Norman, C, Olds, R, Parish, C, Ryle, M, Schmitzer, M, Sherman, P, Skeen, M, Susak, M, Sutter, B, Tran, Q, Welch, C, Witherspoon, R, Wood, J, Zareski, J, Arvizu-Jakubicki, M, Asphaug, E, Audi, E, Ballouz, R-L, Bandrowski, R, Becker, KJ, Becker, TL, Bendall, S, Bennett, CA, Bloomenthal, H, Blum, D, Boynton, W, Brodbeck, J, Burke, KN, Chojnacki, M, Colpo, A, Contreras, J, Cutts, J, Dean, D, Diallo, B, Drinnon, D, Drozd, K, Enos, HL, Enos, R, Fellows, C, Ferro, T, Fisher, MR, Fitzgibbon, G, Fitzgibbon, M, Forelli, J, Forrester, T, Galinsky, I, Garcia, R, Gardner, A, Habib, N, Hamara, D, Hammond, D, Hanley, K, Harshman, K, Herzog, K, Hill, D, Hoekenga, C, Hooven, S, Huettner, E, Janakus, A, Jones, J, Kidd, J, Kingsbury, K, Balram-Knutson, SS, Koelbel, L, Kreiner, J, Lambert, D, Lewin, C, Lovelace, B, Loveridge, M, Lujan, M, Malhotra, R, Marchese, K, McDonough, E, Mogk, N, Morrison, V, Morton, E, Munoz, R, Nelson, J, Padilla, J, Pennington, R, Polit, A, Ramos, N, Reddy, V, Riehl, M, Roper, HL, Salazar, S, Schwartz, SR, Selznick, S, Shultz, N, Stewart, S, Sutton, S, Swindle, T, Tang, YH, Westermann, M, Wolner, CW, Worden, D, Zega, T, Zeszut, Z, Bjurstrom, A, Bloomquist, L, Dickinson, C, Keates, E, Liang, J, Nifo, V, Taylor, A, Teti, F, Caplinger, M, Bowles, H, Carter, S, Dickenshied, S, Doerres, D, Fisher, T, Hagee, W, Hill, J, Miner, M, Noss, D, Piacentine, N, Smith, M, Toland, A, Wren, P, Bernacki, M, Munoz, DP, Watanabe, S, Sandford, SA, Aqueche, A, Ashman, B, Barker, M, Bartels, A, Berry, K, Bos, B, Burns, R, Calloway, A, Carpenter, R, Castro, N, Cosentino, R, Donaldson, J, Dworkin, JP, Cook, JE, Emr, C, Everett, D, Fennell, D, Fleshman, K, Folta, D, Gallagher, D, Garvin, J, Getzandanner, K, Glavin, D, Hull, S, Hyde, K, Ido, H, Ingegneri, A, Jones, N, Kaotira, P, Lim, LF, Liounis, A, Lorentson, C, Lorenz, D, Lyzhoft, J, Mazarico, EM, Mink, R, Moore, W, Moreau, M, Mullen, S, Nagy, J, Neumann, G, Nuth, J, Poland, D, Reuter, DC, Rhoads, L, Rieger, S, Rowlands, D, Sallitt, D, Scroggins, A, Shaw, G, Simon, AA, Swenson, J, Vasudeva, P, Wasser, M, Zellar, R, Grossman, J, Johnston, G, Morris, M, Wendel, J, Burton, A, Keller, LP, McNamara, L, Messenger, S, Nakamura-Messenger, K, Nguyen, A, Righter, K, Queen, E, Bellamy, K, Dill, K, Gardner, S, Giuntini, M, Key, B, Kissell, J, Patterson, D, Vaughan, D, Wright, B, Gaskell, RW, Le Corre, L, Molaro, JL, Palmer, EE, Siegler, MA, Tricarico, P, Weirich, JR, Ireland, T, Tait, K, Bland, P, Anwar, S, Bojorquez-Murphy, N, Christensen, PR, Haberle, CW, Mehall, G, Rios, K, Franchi, I, Rozitis, B, Beddingfield, CB, Marshall, J, Brack, DN, French, AS, McMahon, JW, Jawin, ER, McCoy, TJ, Russell, S, Killgore, M, Bottke, WF, Hamilton, VE, Kaplan, HH, Walsh, KJ, Bandfield, JL, Clark, BC, Chodas, M, Lambert, M, Masterson, RA, Daly, MG, Freemantle, J, Seabrook, JA, Barnouin, OS, Craft, K, Daly, RT, Ernst, C, Espiritu, RC, Holdridge, M, Jones, M, Nair, AH, Nguyen, L, Peachey, J, Perry, ME, Plescia, J, Roberts, JH, Steele, R, Turner, R, Backer, J, Edmundson, K, Mapel, J, Milazzo, M, Sides, S, Manzoni, C, May, B, Delbo, M, Libourel, G, Michel, P, Ryan, A, Thuillet, F, and Marty, B

Abstract

During its approach to asteroid (101955) Bennu, NASA's Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) spacecraft surveyed Bennu's immediate environment, photometric properties, and rotation state. Discovery of a dusty environment, a natural satellite, or unexpected asteroid characteristics would have had consequences for the mission's safety and observation strategy. Here we show that spacecraft observations during this period were highly sensitive to satellites (sub-meter scale) but reveal none, although later navigational images indicate that further investigation is needed. We constrain average dust production in September 2018 from Bennu's surface to an upper limit of 150 g s-1 averaged over 34 min. Bennu's disk-integrated photometric phase function validates measurements from the pre-encounter astronomical campaign. We demonstrate that Bennu's rotation rate is accelerating continuously at 3.63 ± 0.52 × 10-6 degrees day-2, likely due to the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect, with evolutionary implications.

Published
2019

36. Shape model and spin-state analysis of PHA contact binary (85990) 1999 JV6 from combined radar and optical observations

Author

Rożek, A., primary, Lowry, S. C., additional, Nolan, M. C., additional, Taylor, P. A., additional, Benner, L. A. M., additional, Fitzsimmons, A., additional, Zegmott, T. J., additional, Weissman, P. R., additional, Green, S. F., additional, Rozitis, B., additional, Snodgrass, C., additional, Smythe, W. D., additional, Hicks, M. D., additional, Howell, E. S., additional, Virkki, A. K., additional, Aponte-Hernandez, B., additional, Rivera-Valentín, E. G., additional, Rodriguez-Ford, L. A., additional, Zambrano-Marin, L. F., additional, Brozović, M., additional, Naidu, S. P., additional, Giorgini, J. D., additional, Snedeker, L. G., additional, Jao, J. S., additional, and Ghigo, F. D., additional

Published
2019
Full Text
View/download PDF

37. Physical model of near-Earth asteroid (1917) Cuyo from ground-based optical and thermal-IR observations

Author

Rożek, A., primary, Lowry, S. C., additional, Rozitis, B., additional, Green, S. F., additional, Snodgrass, C., additional, Weissman, P. R., additional, Fitzsimmons, A., additional, Hicks, M. D., additional, Lawrence, K. J., additional, Duddy, S. R., additional, Wolters, S. D., additional, Roberts-Borsani, G., additional, Behrend, R., additional, and Manzini, F., additional

Published
2019
Full Text
View/download PDF

40. The Surface Roughness of (433) Eros as Measured by Thermal-Infrared Beaming

Author

Rozitis, B.

Subjects
Surface (mathematics), Physics, Sunlight, Earth and Planetary Astrophysics (astro-ph.EP), Gravity (chemistry), 010504 meteorology & atmospheric sciences, business.industry, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Latitude, Optics, Planetary science, Space and Planetary Science, Asteroid, 0103 physical sciences, Physics::Space Physics, Spatial ecology, Surface roughness, Astrophysics::Earth and Planetary Astrophysics, business, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract

In planetary science, surface roughness is regarded to be a measure of surface irregularity at small spatial scales, and causes the thermal-infrared beaming effect (i.e. re-radiation of absorbed sunlight back towards to the Sun). Typically, surface roughness exhibits a degeneracy with thermal inertia when thermophysical models are fitted to disc-integrated thermal-infrared observations of asteroids because of this effect. In this work, it is demonstrated how surface roughness can be constrained for near-Earth asteroid (433) Eros (i.e. the target of NASA's NEAR Shoemaker mission) when using the Advanced Thermophysical Model with thermal-infrared observations taken during an "almost pole-on" illumination and viewing geometry. It is found that the surface roughness of (433) Eros is characterised by an RMS slope of 38 $\pm$ 8{\deg} at the 0.5-cm spatial scale associated with its thermal-infrared beaming effect. This is slightly greater than the RMS slope of 25 $\pm$ 5{\deg} implied by the NEAR Shoemaker laser ranging results when extrapolated to this spatial scale, and indicates that other surface shaping processes might operate, in addition to collisions and gravity, at spatial scales under one metre in order to make asteroid surfaces rougher. For other high obliquity asteroids observed during "pole-on" illumination conditions, the thermal-infrared beaming effect allows surface roughness to be constrained when the sub-solar latitude is greater than 60{\deg}, and if the asteroids are observed at phase angles of less than 40{\deg}. They will likely exhibit NEATM beaming parameters that are lower than expected for a typical asteroid at all phase angles up to 100{\deg}., Comment: 23 pages, 8 figures, 2 tables. Accepted by MNRAS

Published
2016
Full Text
View/download PDF

42. The Influence of Global Self-Heating on the Yarkovsky and YORP Effects

Author

Rozitis, B. and Green, S. F.

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Physics, Angular acceleration, Yarkovsky effect, FOS: Physical sciences, Astronomy and Astrophysics, Relative strength, Mechanics, Celestial mechanics, Gravitation, Classical mechanics, Recoil, Space and Planetary Science, Asteroid, Physics::Space Physics, SPHERES, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

We present an adaptation of the ATPM to simultaneously predict the Yarkovsky and YORP effects in the presence of global self-heating that occurs within the large concavities of irregularly shaped asteroids, which has been neglected or dismissed in all previous models. It is also combined with rough surface thermal-infrared beaming effects, which have been previously shown to enhance the Yarkovsky-orbital-drift and dampen on average the YORP-rotational-acceleration by orders of several tens of per cent. Tests on all published concave shape models of near-Earth asteroids, and also on one hundred Gaussian-random-spheres, show that the Yarkovsky effect is sensitive to shadowing and global self-heating effects at the few per cent level or less. For simplicity, Yarkovsky models can neglect these effects if the level of accuracy desired is of this order. Unlike the Yarkovsky effect, the YORP effect can be very sensitive to shadowing and global self-heating effects. Its sensitivity increases with decreasing relative strength of the YORP-rotational-acceleration, and doesn't appear to depend greatly on the degree of asteroid concavity. Global self-heating tends to produce a vertical offset in an asteroid's YORP-rotational-acceleration versus obliquity curve which is in opposite direction to that produced by shadowing effects. It also ensures that at least one critical obliquity angle exists at which zero YORP-rotational-acceleration occurs. Global self-heating must be included for accurate predictions of the YORP effect if an asteroid exhibits a large shadowing effect. If global self-heating effects are not included then it is found in ~75 per cent of cases that better predictions are produced when shadowing is also not included. Furthermore, global self-heating has implications for reducing the sensitivity of the YORP effect predictions to detailed variations in an asteroid's shape model., 39 pages, 12 figures, 3 tables. Accepted by MNRAS

Published
2013

43. Constraints on the near-Earth asteroid obliquity distribution from the Yarkovsky effect.

Author

Tardioli, C., Farnocchia, D., Rozitis, B., Cotto-Figueroa, D., Chesley, S. R., Statler, T. S., and Vasile, M.

Subjects
NEAR-earth asteroids, YARKOVSKY effect, INVERSION (Geophysics), CELESTIAL mechanics, LIGHT curves
Abstract

Aims. From light curve and radar data we know the spin axis of only 43 near-Earth asteroids. In this paper we attempt to constrain the spin axis obliquity distribution of near-Earth asteroids by leveraging the Yarkovsky effect and its dependence on an asteroid's obliquity. Methods. By modeling the physical parameters driving the Yarkovsky effect, we solve an inverse problem where we test different simple parametric obliquity distributions. Each distribution results in a predicted Yarkovsky effect distribution that we compare with a X2 test to a dataset of 125 Yarkovsky estimates. Results. We find different obliquity distributions that are statistically satisfactory. In particular, among the considered models, the best-fit solution is a quadratic function, which only depends on two parameters, favors extreme obliquities consistent with the expected outcomes from the YORP effect, has a 2:1 ratio between retrograde and direct rotators, which is in agreement with theoretical predictions, and is statistically consistent with the distribution of known spin axes of near-Earth asteroids. [ABSTRACT FROM AUTHOR]

Published
2018
Full Text
View/download PDF

44. The influence of rough surface thermal-infrared beaming on the Yarkovsky and YORP effects

Author

Rozitis, B. and Green, S. F.

Subjects
Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics
Abstract

It is now becoming widely accepted that photon recoil forces from the asymmetric reflection and thermal re-radiation of absorbed sunlight are, together with collisions and gravitational forces, primary mechanisms governing the dynamical and physical evolution of asteroids. The Yarkovsky effect causes orbital semimajor axis drift, and the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect causes changes in the rotation rate and pole orientation. We present an adaptation of the Advanced Thermophysical Model to simultaneously predict the Yarkovsky and YORP effects in the presence of thermal-infrared beaming caused by surface roughness, which has been neglected or dismissed in all previous models. Tests on Gaussian random sphere shaped asteroids, and on the real shapes of asteroids (1620) Geographos and (6489) Golevka, show that rough surface thermal-infrared beaming enhances the Yarkovsky orbital drift by typically tens of per cent but it can be as much as a factor of 2. The YORP rotational acceleration is on average dampened by up to a third typically but can be as much as one-half. We find that the Yarkovsky orbital drift is only sensitive to the average degree, and not to the spatial distribution, of roughness across an asteroid surface. However, the YORP rotational acceleration is sensitive to the surface roughness spatial distribution, and can add significant uncertainties to the predictions for asteroids with relatively weak YORP effects. To accurately predict either effect the degree and spatial distribution of roughness across an asteroid surface must be known.

Published
2012

45. Directional characteristics of thermal-infrared beaming from atmosphereless planetary surfaces - a new thermophysical model

Author

Rozitis, B. and Green, S. F.

Subjects
Astrophysics::Earth and Planetary Astrophysics
Abstract

We present a new rough-surface thermophysical model (Advanced Thermophysical Model or ATPM) that describes the observed directional thermal emission from any atmosphereless planetary surface. It explicitly incorporates partial shadowing, scattering of sunlight, self-heating and thermal–infrared beaming (re-radiation of absorbed sunlight back towards the Sun as a result of surface roughness). The model is verified by accurately reproducing ground-based directional thermal emission measurements of the lunar surface using surface properties that are consistent with the findings of the Apollo missions and roughness characterized by an rms slope of ∼32°. By considering the wide range of potential asteroid surface properties, the model implies a beaming effect that cannot be described by a simple parameter or function. It is highly dependent on the illumination and viewing angles as well as surface thermal properties and is predominantly caused by macroscopic rather than microscopic roughness. Roughness alters the effective Bond albedo and thermal inertia of the surface as well as moving the mean emission away from the surface normal. For accurate determination of surface properties from thermal–infrared observations of unresolved bodies or resolved surface elements, roughness must be explicitly modelled, preferably aided with thermal measurements at different emission angles and wavelengths.

Published
2011

46. THERMAP: a mid-infrared spectro-imager for space missions to small bodies in the inner solar system

Author

Groussin, O., primary, Licandro, J., additional, Helbert, J., additional, Reynaud, J. L., additional, Levacher, P., additional, Reyes García-Talavera, M., additional, Alí-Lagoa, V., additional, Blanc, P. E., additional, Brageot, E., additional, Davidsson, B., additional, Delbó, M., additional, Deleuze, M., additional, Delsanti, A., additional, Diaz Garcia, J. J., additional, Dohlen, K., additional, Ferrand, D., additional, Green, S. F., additional, Jorda, L., additional, Joven Álvarez, E., additional, Knollenberg, J., additional, Kührt, E., additional, Lamy, P., additional, Lellouch, E., additional, Le Merrer, J., additional, Marty, B., additional, Mas, G., additional, Rossin, C., additional, Rozitis, B., additional, Sunshine, J., additional, Vernazza, P., additional, and Vives, S., additional

Published
2015
Full Text
View/download PDF

47. The internal structure of asteroid (25143) Itokawa as revealed by detection of YORP spin-up

Author

Lowry, S.C., Weissman, P.R., Duddy, S.R., Rozitis, B., Fitzsimmons, A., Green, S.F., Hicks, M.D., Snodgrass, C., Wolters, S.D., Chesley, S.R., Pittichová, J., Van Oers, P., Lowry, S.C., Weissman, P.R., Duddy, S.R., Rozitis, B., Fitzsimmons, A., Green, S.F., Hicks, M.D., Snodgrass, C., Wolters, S.D., Chesley, S.R., Pittichová, J., and Van Oers, P.

Abstract

Context. Near-Earth asteroid (25143) Itokawa was visited by the Hayabusa spacecraft in 2005, resulting in a highly detailed shape and surface topography model. This model has led to several predictions for the expected radiative torques on this asteroid, suggesting that its spin rate should be decelerating. Aims. To detect changes in rotation rate that may be due to YORP-induced radiative torques, which in turn may be used to investigate the interior structure of the asteroid. Methods. Through an observational survey spanning 2001 to 2013 we obtained rotational lightcurve data at various times over the last five close Earth-approaches of the asteroid. We applied a polyhedron-shape-modelling technique to assess the spin-state of the asteroid and its long term evolution. We also applied a detailed thermophysical analysis to the shape model determined from the Hayabusa spacecraft. Results. We have successfully measured an acceleration in Itokawa's spin rate of dÏ?/dt = (3.54 ± 0.38) Ã? 10-8 rad day-2, equivalent to a decrease of its rotation period of ~45 ms year-1. From the thermophysical analysis we find that the centre-of-mass for Itokawa must be shifted by ~21 m along the long-axis of the asteroid to reconcile the observed YORP strength with theory. Conclusions. This can be explained if Itokawa is composed of two separate bodies with very different bulk densities of 1750 ± 110 kg m-3 and 2850 ± 500 kg m-3, and was formed from the merger of two separate bodies, either in the aftermath of a catastrophic disruption of a larger differentiated body, or from the collapse of a binary system. We therefore demonstrate that an observational measurement of radiative torques, when combined with a detailed shape model, can provide insight into the interior structure of an asteroid. Futhermore, this is the first measurement of density inhomogeneity within an asteroidal body, that reveals significant internal structure variation. A specialised spacecraft is normally required f

Published
2014

48. The surface roughness of (433) Eros as measured by thermal-infrared beaming.

Author

Rozitis, B.

Subjects
*SURFACE roughness, *LASER ranging, *ASTROPHYSICS, *METAPHYSICAL cosmology, *INFRARED radiation
Abstract

In planetary science, surface roughness is regarded to be a measure of surface irregularity at small spatial scales, and causes the thermal-infrared beaming effect (i.e. re-radiation of absorbed sunlight back towards to the Sun). Typically, surface roughness exhibits a degeneracy with thermal inertia when thermophysical models are fitted to disc-integrated thermal-infrared observations of asteroids because of this effect. In this work, it is demonstrated how surface roughness can be constrained for near-Earth asteroid (433) Eros (i.e. the target of NASA's NEAR Shoemaker mission) when using the Advanced Thermophysical Model with thermalinfrared observations taken during an 'almost pole-on' illumination and viewing geometry. It is found that the surface roughness of (433) Eros is characterized by an rms slope of 38 ± 8° at the 0.5-cm spatial scale associated with its thermal-infrared beaming effect. This is slightly greater than the rms slope of 25 ± 5° implied by the NEAR Shoemaker laser ranging results when extrapolated to this spatial scale, and indicates that other surface shaping processes might operate, in addition to collisions and gravity, at spatial scales under one metre in order to make asteroid surfaces rougher. For other high-obliquity asteroids observed during 'pole-on' illumination conditions, the thermal-infrared beaming effect allows surface roughness to be constrained when the sub-solar latitude is greater than 60°, and if the asteroids are observed at phase angles of less than 40°. They will likely exhibit near-Earth asteroid thermalmodel beaming parameters that are lower than expected for a typical asteroid at all phase angles up to 100°. [ABSTRACT FROM AUTHOR]

Published
2017
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results