Log in

Relevant bibliographies by topics / Bennu / Journal articles

Journal articles on the topic 'Bennu'

To see the other types of publications on this topic, follow the link: Bennu.

Author: Grafiati

Published: 10 March 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Bennu.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Stewart, Arthur J. "Asteroid Bennu." Hoosier Science Teacher 44, no. 1 (November 5, 2021): 14. http://dx.doi.org/10.14434/thst.v44i102.

Full text

Abstract:

This poem, Asteroid Bennu, highlights the essence of a common scientific pathway: as surprise finding, followed by a careful analysis that culminates in an either-or type of outcome, usually testable as a hypothesis.

APA, Harvard, Vancouver, ISO, and other styles

2

Maltagliati, Luca. "Cometary Bennu?" Nature Astronomy 2, no. 10 (September 24, 2018): 761. http://dx.doi.org/10.1038/s41550-018-0599-5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Włodarczyk, I. "The Potentially Dangerous Asteroid (101955) Bennu." Physics Research International 2014 (December 15, 2014): 1–13. http://dx.doi.org/10.1155/2014/561680.

Full text

Abstract:

We computed impact solutions of the potentially dangerous asteroid (101955) Bennu based on 569 optical observations from September 11.40624 UTC, 1999 to January 20.11189 UTC, 2013, and 29 radar observations from September 21, 1999, through September 29, 2011. Using the freely available OrbFit software package, we can follow its orbit forward in the future searching for close approaches with the earth, which can lead to possible impacts up to 2200. With the A2 nongravitational parameter in the motion of the asteroid (101955) Bennu we computed possible impact solutions using different JPL planetary and lunar ephemerides and different number of additional massive perturbed asteroids. The possible impact path of risk for 2175 is presented. Additionally, we computed possible impact solutions using the normal places method of the selection of Bennu’s astrometric observations. Moreover, we computed time evolution of the mean orbital elements and the orbital nodes of Bennu 5 kyr in the backwards and 1 kyr in the future using the Yarkovsky effects. We computed the mean motion and secular orbital resonances of the Bennu. We also computed the influence of the JPL planetary and lunar ephemerides DE403, DE405, DE406, DE414, and DE423 on the close approaches of the asteroid (101955) Bennu with the earth.

APA, Harvard, Vancouver, ISO, and other styles

4

Fornasier, S., P. H. Hasselmann, J. D. P. Deshapriya, M. A. Barucci, B. E. Clark, A. Praet, V. E. Hamilton, et al. "Phase reddening on asteroid Bennu from visible and near-infrared spectroscopy." Astronomy & Astrophysics 644 (December 2020): A142. http://dx.doi.org/10.1051/0004-6361/202039552.

Full text

Abstract:

Context. The NASA mission OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer) has been observing near-Earth asteroid (101955) Bennu in close proximity since December 2018. In October 2020, the spacecraft collected a sample of surface material from Bennu to return to Earth. Aims. In this work, we investigate spectral phase reddening – that is, the variation of spectral slope with phase angle – on Bennu using spectra acquired by the OSIRIS-REx Visible and InfraRed Spectrometer (OVIRS) covering a phase angle range of 8–130°. We investigate this process at the global scale and for some localized regions of interest (ROIs), including boulders, craters, and the designated sample collection sites of the OSIRIS-REx mission. Methods. Spectra were wavelength- and flux-calibrated, then corrected for the out-of-band contribution and thermal emission, resampled, and finally converted into radiance factor per standard OVIRS processing. Spectral slopes were computed in multiple wavelength ranges from spectra normalized at 0.55 μm. Results. Bennu has a globally negative spectra slope, which is typical of B-type asteroids. The spectral slope gently increases in a linear way up to a phase angle of 90°, where it approaches zero. The spectral phase reddening is monotonic and wavelength-dependent with highest values in the visible range. Its coefficient is 0.00044 μm−1 deg−1 in the 0.55–2.5 μm range. For observations of Bennu acquired at high phase angle (130°), phase reddening increases exponentially, and the spectral slope becomes positive. Similar behavior was reported in the literature for the carbonaceous chondrite Mukundpura in spectra acquired at extreme geometries. Some ROIs, including the sample collection site, Nightingale, have a steeper phase reddening coefficient than the global average, potentially indicating a surface covered by fine material with high micro-roughness. Conclusions. The gentle spectral phase reddening effect on Bennu is similar to that observed in ground-based measurements of other B-type asteroids, but much lower than that observed for other low-albedo bodies such as Ceres or comet 67P/Churyumov-Gerasimenko. Monotonic reddening may be associated with the presence of fine particles at micron scales and/or of particles with fractal structure that introduce micro- and sub-micro roughness across the surface of Bennu.

APA, Harvard, Vancouver, ISO, and other styles

5

Hanna, Kerri Donaldson. "Playing TAG with Bennu." Astronomy & Geophysics 62, no. 1 (February 1, 2021): 1.14–1.18. http://dx.doi.org/10.1093/astrogeo/atab038.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Simon, A. A., H. H. Kaplan, E. Cloutis, V. E. Hamilton, C. Lantz, D. C. Reuter, D. Trang, S. Fornasier, B. E. Clark, and D. S. Lauretta. "Weak spectral features on (101995) Bennu from the OSIRIS-REx Visible and InfraRed Spectrometer." Astronomy & Astrophysics 644 (December 2020): A148. http://dx.doi.org/10.1051/0004-6361/202039688.

Full text

Abstract:

Context. The NASA Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission has obtained thousands of spectra of asteroid (101955) Bennu with the OSIRIS-REx Visible and InfraRed Spectrometer. Aims. We present a spectral search for minor absorption bands and determine compositional variations on the surface of Bennu. Methods. Reflectance spectra with low and high spatial resolutions were analyzed for evidence of weak absorption bands. Spectra were also divided by a global average spectrum to isolate unique spectral features, and variations in the strongest band depths were mapped on a surface shape model. The global visible to near-IR spectrum of Bennu shows evidence of several weak absorption bands with depths of a few percent. Results. Several observed bands are consistent with phyllosilicates, and their distribution correlates with the stronger 2.74-μm hydration band. A 0.55-μm band is consistent with iron oxides and is deepest in the spectrally reddest areas on Bennu. The presence of hydrated phyllosilicates and iron oxides indicates substantial aqueous alteration in Bennu’s past. Conclusions. Bennu’s spectra are not identical to a limited set of carbonaceous chondrite spectra, possibly due to compositional properties and spatial scale differences; however, returned samples should contain a mixture of common chondrite materials.

APA, Harvard, Vancouver, ISO, and other styles

7

Edmundson, K. L., K. J. Becker, T. L. Becker, C. A. Bennett, D. N. DellaGiustina, D. R. Golish, N. A. Porter, et al. "PHOTOGRAMMETRIC PROCESSING OF OSIRIS-REX IMAGES OF ASTEROID (101955) BENNU." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences V-3-2020 (August 3, 2020): 587–94. http://dx.doi.org/10.5194/isprs-annals-v-3-2020-587-2020.

Full text

Abstract:

Abstract. The principal objective of the Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS-REx) mission is to retrieve a sample of the asteroid (101955) Bennu and return it to Earth. OSIRIS-REx arrived at Bennu in December 2018. Images of the asteroid by the OSIRIS-REx Camera Suite (OCAMS) were photogrammetrically controlled to produce a global basemap and site-specific image mosaics essential to the selection of a primary and backup sample site, which were announced in December 2019. In the control process, OCAMS images were registered to shape models created from OSIRIS-REx Laser Altimeter (OLA) data and from the process of stereophotoclinometry. This paper summarizes the photogrammetric control to date of images collected at Bennu. We briefly review the mission and the OCAMS imaging sensors. We then describe the photogrammetric control process for the global mapping campaign and targeted reconnaissance surveys of candidate sample sites. Finally, we discuss ongoing and future work.

APA, Harvard, Vancouver, ISO, and other styles

8

Merlin, F., J. D. P. Deshapriya, S. Fornasier, M. A. Barucci, A. Praet, P. H. Hasselmann, B. E. Clark, et al. "In search of Bennu analogs: Hapke modeling of meteorite mixtures." Astronomy & Astrophysics 648 (April 2021): A88. http://dx.doi.org/10.1051/0004-6361/202140343.

Full text

Abstract:

Context. The OSIRIS-REx Visible and InfraRed Spectrometer onboard the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer spacecraft obtained many spectra from the surface of the near-Earth asteroid (101955) Bennu, enabling the characterization of this primitive small body. Bennu is spectrally similar to the hydrated carbonaceous chondrites (CCs), but questions remain as to which CCs, or combinations thereof, offer the best analogy to its surface. Aims. We aim to understand in more detail the composition and particle size of Bennu’s surface by refining the relationship between this asteroid and various CC meteorites. Methods. We used published absorbance and reflectance data to identify new optical constants for various CC meteorites measured in the laboratory at different temperatures. We then used the Hapke model to randomly generate 1000 synthetic spectra in order to find the combinations of these potential meteoritic analogs that best reproduce the spectral features of the asteroid. Results. Our investigations suggest that the surface of Bennu, though visibly dominated by boulders and coarse rubble, is covered by small particles (tens to a few hundreds of μm) and that possibly dust or powder covers the larger rocks. We further find that the surface is best modeled using a mixture of heated CM, C2-ungrouped, and, to some extent, CI materials. Conclusions. Bennu is best approximated spectrally by a combination of CC materials and may not fall into an existing CC group.

APA, Harvard, Vancouver, ISO, and other styles

9

Crane, Leah. "Up close with asteroid Bennu." New Scientist 240, no. 3207 (December 2018): 12. http://dx.doi.org/10.1016/s0262-4079(18)32238-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Henshall, Tom. "The surface of asteroid Bennu." Nature Reviews Materials 4, no. 4 (March 22, 2019): 228. http://dx.doi.org/10.1038/s41578-019-0102-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Keane, James Tuttle. "The geologic history of Bennu." Nature Geoscience 12, no. 4 (March 19, 2019): 226. http://dx.doi.org/10.1038/s41561-019-0342-6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Enos, H. L., and D. S. Lauretta. "A rendezvous with asteroid Bennu." Nature Astronomy 3, no. 4 (April 2019): 363. http://dx.doi.org/10.1038/s41550-019-0739-6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Scheeres, D. J., S. G. Hesar, S. Tardivel, M. Hirabayashi, D. Farnocchia, J. W. McMahon, S. R. Chesley, et al. "The geophysical environment of Bennu." Icarus 276 (September 2016): 116–40. http://dx.doi.org/10.1016/j.icarus.2016.04.013.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Kaplan, H. H., A. A. Simon, V. E. Hamilton, M. S. Thompson, S. A. Sandford, M. A. Barucci, E. A. Cloutis, et al. "Composition of organics on asteroid (101955) Bennu." Astronomy & Astrophysics 653 (September 2021): L1. http://dx.doi.org/10.1051/0004-6361/202141167.

Full text

Abstract:

Context. The Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission detected an infrared absorption at 3.4 μm on near-Earth asteroid (101955) Bennu. This absorption is indicative of carbon species, including organics, on the surface. Aims. We aim to describe the composition of the organic matter on Bennu by investigating the spectral features in detail. Methods. We use a curated set of spectra acquired by the OSIRIS-REx Visible and InfraRed Spectrometer that have features near 3.4 μm (3.2 to 3.6 μm) attributed to organics. We assess the shapes and strengths of these absorptions in the context of laboratory spectra of extraterrestrial organics and analogs. Results. We find spectral evidence of aromatic and aliphatic CH bonds. The absorptions are broadly consistent in shape and depth with those associated with insoluble organic matter in meteorites. Given the thermal and space weathering environments on Bennu, it is likely that the organics have not been exposed for long enough to substantially decrease the H/C and destroy all aliphatic molecules.

APA, Harvard, Vancouver, ISO, and other styles

15

Kaplan, H. H., D. S. Lauretta, A. A. Simon, V. E. Hamilton, D. N. DellaGiustina, D. R. Golish, D. C. Reuter, et al. "Bright carbonate veins on asteroid (101955) Bennu: Implications for aqueous alteration history." Science 370, no. 6517 (October 8, 2020): eabc3557. http://dx.doi.org/10.1126/science.abc3557.

Full text

Abstract:

The composition of asteroids and their connection to meteorites provide insight into geologic processes that occurred in the early Solar System. We present spectra of the Nightingale crater region on near-Earth asteroid Bennu with a distinct infrared absorption around 3.4 micrometers. Corresponding images of boulders show centimeters-thick, roughly meter-long bright veins. We interpret the veins as being composed of carbonates, similar to those found in aqueously altered carbonaceous chondrite meteorites. If the veins on Bennu are carbonates, fluid flow and hydrothermal deposition on Bennu’s parent body would have occurred on kilometer scales for thousands to millions of years. This suggests large-scale, open-system hydrothermal alteration of carbonaceous asteroids in the early Solar System.

APA, Harvard, Vancouver, ISO, and other styles

16

Olds, R. D., C. J. Miller, C. D. Norman, C. E. Mario, K. Berry, E. Palmer, O. S. Barnouin, et al. "The Use of Digital Terrain Models for Natural Feature Tracking at Asteroid Bennu." Planetary Science Journal 3, no. 5 (May 1, 2022): 100. http://dx.doi.org/10.3847/psj/ac5184.

Full text

Abstract:

Abstract The Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS-REx) mission rendezvoused with asteroid (101955) Bennu in 2018 with the primary objective of collecting a sample of regolith from the surface. As the first NASA asteroid sample return mission, OSIRIS-REx deployed several new technologies to achieve program objectives. Here we present an overview of Natural Feature Tracking (NFT), a system developed to autonomously guide the spacecraft to the desired sampling site using optical navigation and the natural terrain on the surface of Bennu. NFT utilized a series of image-based digital terrain models (DTMs) constructed by means of stereophotoclinometry to represent patches on the surface of the asteroid. These DTMs were used to generate synthetic renderings of the terrain and identify features for use in navigating to the sampling location. In addition, high-resolution models of the sampling site constructed from scanning lidar data were used for predicting the time and location of contact with the surface. These models went through a series of validation tests to ensure the performance of the NFT system. When the spacecraft executed the sampling trajectory in 2020 October, NFT enabled real-time guidance updates that delivered it safely to the desired sampling location while also providing critical hazard avoidance capabilities in the rocky Bennu environment.

APA, Harvard, Vancouver, ISO, and other styles

17

Smith, Keith T. "Bennu ejects material from its surface." Science 366, no. 6470 (December 5, 2019): 1209.11–1211. http://dx.doi.org/10.1126/science.366.6470.1209-k.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Hasabelnaby, Magda. "Bennu: Ecocriticism from an Egyptian Perspective." ISLE: Interdisciplinary Studies in Literature and Environment 26, no. 4 (2019): 1084–87. http://dx.doi.org/10.1093/isle/isz114.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Lauretta, D. S., C. W. Hergenrother, S. R. Chesley, J. M. Leonard, J. Y. Pelgrift, C. D. Adam, M. Al Asad, et al. "Episodes of particle ejection from the surface of the active asteroid (101955) Bennu." Science 366, no. 6470 (December 5, 2019): eaay3544. http://dx.doi.org/10.1126/science.aay3544.

Full text

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.

APA, Harvard, Vancouver, ISO, and other styles

20

Zhu, Linlin, Xun Geng, Zheng Li, and Chun Liu. "Improving YOLOv5 with Attention Mechanism for Detecting Boulders from Planetary Images." Remote Sensing 13, no. 18 (September 20, 2021): 3776. http://dx.doi.org/10.3390/rs13183776.

Full text

Abstract:

It is of great significance to apply the object detection methods to automatically detect boulders from planetary images and analyze their distribution. This contributes to the selection of candidate landing sites and the understanding of the geological processes. This paper improves the state-of-the-art object detection method of YOLOv5 with attention mechanism and designs a pyramid based approach to detect boulders from planetary images. A new feature fusion layer has been designed to capture more shallow features of the small boulders. The attention modules implemented by combining the convolutional block attention module (CBAM) and efficient channel attention network (ECA-Net) are also added into YOLOv5 to highlight the information that contribute to boulder detection. Based on the Pascal Visual Object Classes 2007 (VOC2007) dataset which is widely used for object detection evaluations and the boulder dataset that we constructed from the images of Bennu asteroid, the evaluation results have shown that the improvements have increased the performance of YOLOv5 by 3.4% in precision. With the improved YOLOv5 detection method, the pyramid based approach extracts several layers of images with different resolutions from the large planetary images and detects boulders of different scales from different layers. We have also applied the proposed approach to detect the boulders on Bennu asteroid. The distribution of the boulders on Bennu asteroid has been analyzed and presented.

APA, Harvard, Vancouver, ISO, and other styles

21

DellaGiustina, D. N., K. N. Burke, K. J. Walsh, P. H. Smith, D. R. Golish, E. B. Bierhaus, R. L. Ballouz, et al. "Variations in color and reflectance on the surface of asteroid (101955) Bennu." Science 370, no. 6517 (October 8, 2020): eabc3660. http://dx.doi.org/10.1126/science.abc3660.

Full text

Abstract:

Visible-wavelength color and reflectance provide information about the geologic history of planetary surfaces. Here we present multispectral images (0.44 to 0.89 micrometers) of near-Earth asteroid (101955) Bennu. The surface has variable colors overlain on a moderately blue global terrain. Two primary boulder types are distinguishable by their reflectance and texture. Space weathering of Bennu surface materials does not simply progress from red to blue (or vice versa). Instead, freshly exposed, redder surfaces initially brighten in the near-ultraviolet region (i.e., become bluer at shorter wavelengths), then brighten in the visible to near-infrared region, leading to Bennu’s moderately blue average color. Craters indicate that the time scale of these color changes is ~105 years. We attribute the reflectance and color variation to a combination of primordial heterogeneity and varying exposure ages.

APA, Harvard, Vancouver, ISO, and other styles

22

Mario, C. E., C. J. Miller, C. D. Norman, E. E. Palmer, J. Weirich, O. S. Barnouin, M. G. Daly, et al. "Ground Testing of Digital Terrain Models to Prepare for OSIRIS-REx Autonomous Vision Navigation Using Natural Feature Tracking." Planetary Science Journal 3, no. 5 (May 1, 2022): 104. http://dx.doi.org/10.3847/psj/ac5182.

Full text

Abstract:

Abstract The OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer) spacecraft collected a sample from the asteroid Bennu in 2020. This achievement leveraged an autonomous optical navigation approach called Natural Feature Tracking (NFT). NFT provided spacecraft state updates by correlating asteroid surface features rendered from previously acquired terrain data with images taken by the onboard navigation camera. The success of NFT was the culmination of years of preparation and collaboration to ensure that feature data would meet navigation requirements. This paper presents the findings from ground testing performed prior to the spacecraft's arrival at Bennu, in which synthetic data were used to develop and validate the technical approach for building NFT features. Correlation sensitivity testing using synthetic models of Bennu enabled the team to characterize the terrain properties that worked well for feature correlation, the challenges posed by smoother terrain, and the impact of imaging conditions on correlation performance. The team found that models constructed from image data by means of stereophotoclinometry (SPC) worked better than those constructed from laser altimetry data, except when test image pixel sizes were more than a factor of 2 smaller than those of the images used for SPC, and when topography was underrepresented and resulted in incorrect shadows in rendered features. Degradation of laser altimetry data related to noise and spatial sampling also led to poor correlation performance. Albedo variation was found to be a key contributor to correlation performance; topographic data alone were insufficient for NFT.

APA, Harvard, Vancouver, ISO, and other styles

23

Simon, Amy A., Hannah H. Kaplan, Victoria E. Hamilton, Dante S. Lauretta, Humberto Campins, Joshua P. Emery, M. Antonietta Barucci, et al. "Widespread carbon-bearing materials on near-Earth asteroid (101955) Bennu." Science 370, no. 6517 (October 8, 2020): eabc3522. http://dx.doi.org/10.1126/science.abc3522.

Full text

Abstract:

Asteroid (101955) Bennu is a dark asteroid on an Earth-crossing orbit that is thought to have assembled from the fragments of an ancient collision. We use spatially resolved visible and near-infrared spectra of Bennu to investigate its surface properties and composition. In addition to a hydrated phyllosilicate band, we detect a ubiquitous 3.4-micrometer absorption feature, which we attribute to a mix of organic and carbonate materials. The shape and depth of this absorption feature vary across Bennu’s surface, spanning the range seen among similar main-belt asteroids. The distribution of the absorption feature does not correlate with temperature, reflectance, spectral slope, or hydrated minerals, although some of those characteristics correlate with each other. The deepest 3.4-micrometer absorptions occur on individual boulders. The variations may be due to differences in abundance, recent exposure, or space weathering.

APA, Harvard, Vancouver, ISO, and other styles

24

Ye, Quanzhi. "Prediction of Meteor Activities from (101955) Bennu." Research Notes of the AAS 3, no. 3 (March 27, 2019): 56. http://dx.doi.org/10.3847/2515-5172/ab12e7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Li, Jian-Yang, Xiao-Duan Zou, Dathon R. Golish, Beth E. Clark, Salvatore Ferrone, Sonia Fornasier, Pedro H. Hasselmann, et al. "Spectrophotometric Modeling and Mapping of (101955) Bennu." Planetary Science Journal 2, no. 3 (June 1, 2021): 117. http://dx.doi.org/10.3847/psj/abfd2d.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Golish, D. R., J. Y. Li, B. E. Clark, D. N. DellaGiustina, X. D. Zou, J. L. Rizos, P. H. Hasselmann, et al. "Regional Photometric Modeling of Asteroid (101955) Bennu." Planetary Science Journal 2, no. 4 (July 2, 2021): 124. http://dx.doi.org/10.3847/psj/abfd3c.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Tricarico, P., D. J. Scheeres, A. S. French, J. W. McMahon, D. N. Brack, J. M. Leonard, P. Antreasian, et al. "Internal rubble properties of asteroid (101955) Bennu." Icarus 370 (December 2021): 114665. http://dx.doi.org/10.1016/j.icarus.2021.114665.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Ngara, Shingai. "Bennu: Africa innovating itself out of underdevelopment." International Journal of African Renaissance Studies - Multi-, Inter- and Transdisciplinarity 6, no. 1 (June 2011): 60–77. http://dx.doi.org/10.1080/18186874.2011.592393.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Moskvitch, K. "News Briefing: In Num6ers - Visiting asteroid Bennu." Engineering & Technology 11, no. 2 (March 1, 2016): 18–19. http://dx.doi.org/10.1049/et.2016.0219.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Lauretta, D. S., D. N. DellaGiustina, C. A. Bennett, D. R. Golish, K. J. Becker, S. S. Balram-Knutson, O. S. Barnouin, et al. "The unexpected surface of asteroid (101955) Bennu." Nature 568, no. 7750 (March 19, 2019): 55–60. http://dx.doi.org/10.1038/s41586-019-1033-6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Deshapriya, J. D. P., M. A. Barucci, E. B. Bierhaus, S. Fornasier, P. H. Hasselmann, F. Merlin, B. E. Clark, et al. "Spectral analysis of craters on (101955) Bennu." Icarus 357 (March 2021): 114252. http://dx.doi.org/10.1016/j.icarus.2020.114252.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Yu, Liangliang, and Jianghui Ji. "Thermophysical Characteristics of OSIRIS-REx Target Asteroid (101955) Bennu." Proceedings of the International Astronomical Union 10, S318 (August 2015): 218–20. http://dx.doi.org/10.1017/s1743921315006985.

Full text

Abstract:

AbstractIn this work, we investigate the thermophysical properties, including thermal inertia, roughness fraction and surface grain size of OSIRIS-REx target asteroid (101955) Bennu by using a thermophysical model with the recently updated 3D radar-derived shape model (Nolan et al., 2013) and mid-infrared observations (Müller et al. 2012, Emery et al., 2014). We find that the asteroid bears an effective diameter of 510+6−40 m, a geometric albedo of 0.047+0.0083−0.0011, a roughness fraction of 0.04+0.26−0.04, and thermal inertia of 240+440−60 Jm−2s−0.5K−1 for our best-fit solution. The best-estimate thermal inertia suggests that fine-grained regolith may cover a large portion of Bennu's surface, where a grain size may vary from 1.3 to 31 mm. Our outcome suggests that Bennu is suitable for the OSIRIS-REx mission to return samples to Earth.

APA, Harvard, Vancouver, ISO, and other styles

33

Liu, Yongjie, Yu Jiang, and Hengnian Li. "Bifurcations of Periodic Orbits in the Gravitational Field of Irregular Bodies: Applications to Bennu and Steins." Aerospace 9, no. 3 (March 8, 2022): 151. http://dx.doi.org/10.3390/aerospace9030151.

Full text

Abstract:

We investigate the topological types and bifurcations of periodic orbits in the gravitational field of irregular bodies by the well-known two parameter analysis method. Results show that the topological types of periodic orbits are determined by the locations of these two parameters and that the bifurcation types correspond to their variation paths in the plane. Several new paths corresponding to doubling period bifurcations, tangent bifurcations and Neimark–Sacker bifurcations are discovered. Then, applications in detecting bifurcations of periodic orbits near asteroids 101955 Bennu and 2867 Steins are presented. It is found that tangent bifurcations may occur three times when continuing the vertical orbits near the equilibrium points of 101955 Bennu. The continuation stops as the Jacobi energy reaches a local maximum. However, while continuing the vertical orbits near the equilibrium points of 2867 Steins, the tangent bifurcation and pseudo period-doubling bifurcation occur. The continuation can always go on, and the orbit ultimately becomes nearly circular.

APA, Harvard, Vancouver, ISO, and other styles

34

Scheeres, D. J., A. S. French, P. Tricarico, S. R. Chesley, Y. Takahashi, D. Farnocchia, J. W. McMahon, et al. "Heterogeneous mass distribution of the rubble-pile asteroid (101955) Bennu." Science Advances 6, no. 41 (October 2020): eabc3350. http://dx.doi.org/10.1126/sciadv.abc3350.

Full text

Abstract:

The gravity field of a small body provides insight into its internal mass distribution. We used two approaches to measure the gravity field of the rubble-pile asteroid (101955) Bennu: (i) tracking and modeling the spacecraft in orbit about the asteroid and (ii) tracking and modeling pebble-sized particles naturally ejected from Bennu’s surface into sustained orbits. These approaches yield statistically consistent results up to degree and order 3, with the particle-based field being statistically significant up to degree and order 9. Comparisons with a constant-density shape model show that Bennu has a heterogeneous mass distribution. These deviations can be modeled with lower densities at Bennu’s equatorial bulge and center. The lower-density equator is consistent with recent migration and redistribution of material. The lower-density center is consistent with a past period of rapid rotation, either from a previous Yarkovsky-O’Keefe-Radzievskii-Paddack cycle or arising during Bennu’s accretion following the disruption of its parent body.

APA, Harvard, Vancouver, ISO, and other styles

35

Rozitis, B., A. J. Ryan, J. P. Emery, P. R. Christensen, V. E. Hamilton, A. A. Simon, D. C. Reuter, et al. "Asteroid (101955) Bennu’s weak boulders and thermally anomalous equator." Science Advances 6, no. 41 (October 2020): eabc3699. http://dx.doi.org/10.1126/sciadv.abc3699.

Full text

Abstract:

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.

APA, Harvard, Vancouver, ISO, and other styles

36

Hamilton, V. E., P. R. Christensen, H. H. Kaplan, C. W. Haberle, A. D. Rogers, T. D. Glotch, L. B. Breitenfeld, et al. "Evidence for limited compositional and particle size variation on asteroid (101955) Bennu from thermal infrared spectroscopy." Astronomy & Astrophysics 650 (June 2021): A120. http://dx.doi.org/10.1051/0004-6361/202039728.

Full text

Abstract:

Context. Asteroid (101955) Bennu is the target of NASA’s Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS-REx) mission. The spacecraft’s instruments have characterized Bennu at global and local scales to select a sampling site and provide context for the sample that will be returned to Earth. These observations include thermal infrared spectral characterization by the OSIRIS-REx Thermal Emission Spectrometer (OTES). Aims. To understand the degree of compositional and particle size variation on Bennu, and thereby predict the nature of the returned sample, we studied OTES spectra, which are diagnostic of these properties. Methods. We created and mapped spectral indices and compared them with the distribution of geomorphic features. Comparison to laboratory spectra of aqueously altered carbonaceous chondrites constrains the amount of compositional variability that is observable. Results. The OTES spectra exhibit two end-member shapes (or types), and compositional variability appears limited at the spatial resolution of the observations. The global distribution of these spectral types corresponds with the locations of regions composed of (i) large, dark, relatively rough boulders and (ii) relatively smooth regions lacking large boulders. Conclusions. The two spectral types appear to be diagnostic primarily of particle size variations, with contributions from other properties. The spectra resemble experimental data of solid substrates with very thin accumulations (a few to tens of microns) of fine particles (<~65–100 μm). The dustier surfaces commonly correspond with rougher rocks that may produce and/or act as traps for the particles. Anhydrous silicates are limited in abundance, and the bulk mineralogy is consistent with the most aqueously altered carbonaceous chondrites. We expect the returned samples to include these physical and mineralogical characteristics.

APA, Harvard, Vancouver, ISO, and other styles

37

Barucci, M. A., P. H. Hasselmann, A. Praet, M. Fulchignoni, J. D. P. Deshapriya, S. Fornasier, F. Merlin, et al. "OSIRIS-REx spectral analysis of (101955) Bennu by multivariate statistics." Astronomy & Astrophysics 637 (May 2020): L4. http://dx.doi.org/10.1051/0004-6361/202038144.

Full text

Abstract:

Contact. The NASA New Frontiers asteroid sample return mission Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS-REx) has provided a large amount of data on the asteroid (101955) Bennu, including high-quality spectra obtained by the OSIRIS-REx Visible and InfraRed Spectrometer (OVIRS). Aims. To better constrain the surface properties and compositional variations of Bennu, we studied the visible and near-infrared spectral behavior across the asteroid surface by means of a statistical analysis aiming to distinguish spectrally distinct groups, if present. Methods. We applied the G-mode multivariate statistical analysis to the near-infrared OVIRS spectra to obtain an automatic statistical clustering at different confidence levels. Results. The statistical analysis highlights spectral variations on the surface of Bennu. Five distinct spectral groups are identified at a 2σ confidence level. At a higher confidence level of 3σ, no grouping is observed. Conclusions. The results at a 2σ confidence level distinguish a dominant spectral behavior group (group 1, background) and four small groups showing spectral slope variations, associated with areas with different surface properties. The background group contains most of the analyzed data, which implies a globally homogeneous surface at the spectral and spatial resolution of the data. The small groups with redder spectra are concentrated around the equatorial ridge and are associated with morphological surface features such as specific craters and boulders. No significant variation is detected in the band area or depth of the 2.74 μm band, which is associated with hydrated phyllosilicate content. The spectral slope variations are interpreted as a consequence of different regolith particle sizes, and/or porosity, and/or space weathering, that is, the presence of more or less fresh material. The OSIRIS-REx mission primary sampling site, Nightingale, and a boulder known as the Roc, are redder than the background surface.

APA, Harvard, Vancouver, ISO, and other styles

38

Praet, A., M. A. Barucci, B. E. Clark, H. H. Kaplan, A. A. Simon, V. E. Hamilton, J. P. Emery, et al. "Hydrogen abundance estimation and distribution on (101955) Bennu." Icarus 363 (July 2021): 114427. http://dx.doi.org/10.1016/j.icarus.2021.114427.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Lauretta, D. S., S. S. Balram-Knutson, E. Beshore, W. V. Boynton, C. Drouet d’Aubigny, D. N. DellaGiustina, H. L. Enos, et al. "OSIRIS-REx: Sample Return from Asteroid (101955) Bennu." Space Science Reviews 212, no. 1-2 (August 28, 2017): 925–84. http://dx.doi.org/10.1007/s11214-017-0405-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Yu, LiangLiang, and Jianghui Ji. "Surface thermophysical properties determination ofOSIRIS-RExtarget asteroid (101955) Bennu." Monthly Notices of the Royal Astronomical Society 452, no. 1 (July 8, 2015): 368–75. http://dx.doi.org/10.1093/mnras/stv1270.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Hamilton, V. E., A. A. Simon, P. R. Christensen, D. C. Reuter, B. E. Clark, M. A. Barucci, N. E. Bowles, et al. "Evidence for widespread hydrated minerals on asteroid (101955) Bennu." Nature Astronomy 3, no. 4 (March 19, 2019): 332–40. http://dx.doi.org/10.1038/s41550-019-0722-2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Hartzell, Christine, Michael Zimmerman, and Carl Hergenrother. "An Evaluation of Electrostatic Lofting and Subsequent Particle Motion on Bennu." Planetary Science Journal 3, no. 4 (April 1, 2022): 85. http://dx.doi.org/10.3847/psj/ac5629.

Full text

Abstract:

Abstract Electrostatic lofting is the detachment of particles from a surface that occurs if the electrostatic force on the particles is greater than the forces binding the particles to the surface. Electrostatic lofting has been hypothesized to occur on the Moon and observed in the laboratory environment. Because gravity is much weaker on asteroids than on the Moon, the hypothesis of electrostatic lofting has naturally been extended to these smaller airless bodies. We evaluate the feasibility of electrostatic lofting on Bennu using two formulations of the patched charge model. We find that submillimeter particles can be lofted from Bennu’s dayside and, depending on their initial conditions, will reimpact or escape. The size and speed of the predicted electrostatically lofted particles are compared to those of the particle ejection events recently observed on Bennu. We find that dayside electrostatic lofting is not consistent with the size and speed of particles in the largest ejection events observed by the OSIRIS-REx mission. However, the escape of submillimeter particles has implications for the particle size distribution on Bennu’s surface. Additionally, we model particle charging on Bennu’s nightside due to secondary electron emission and find the resulting electrostatic force to be too weak to produce electrostatic lofting on the nightside.

APA, Harvard, Vancouver, ISO, and other styles

43

Weirich, John, Eric E. Palmer, Michael G. Daly, Olivier S. Barnouin, Kenneth Getzandanner, John N. Kidd, Coralie D. Adam, Robert Gaskell, and Dante S. Lauretta. "Quality Assessment of Stereophotoclinometry as a Shape Modeling Method Using a Synthetic Asteroid." Planetary Science Journal 3, no. 5 (May 1, 2022): 103. http://dx.doi.org/10.3847/psj/ac46d2.

Full text

Abstract:

Abstract The stereophotoclinometry (SPC) software suite has been used to generate global digital terrain models (DTMs) of many asteroids and moons, and was the primary tool used by the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission to model the shape of asteroid Bennu. We describe the dedicated preflight testing of SPC for the OSIRIS-REx mission using a synthetic “truth” asteroid model. SPC has metrics that determine the internal consistency of a DTM, but it was not known how these metrics are related to the absolute accuracy of a DTM, which was important for the operational needs of the mission. The absolute accuracy of an SPC-generated DTM cannot be determined without knowing the truth topography. Consequently, we developed a realistic, but synthetic, computer-generated representation of asteroid Bennu, photographed this synthetic truth model in an imaging campaign similar to that planned for the OSIRIS-REx mission, and then generated a global SPC DTM from these images. We compared the SPC DTM, which was represented by a radius every 70 cm across the asteroid surface, to the synthetic truth model to assess the absolute accuracy. We found that the internal consistency can be used to determine the 3D root-mean-square accuracy of the model to within a factor of two of the absolute accuracy.

APA, Harvard, Vancouver, ISO, and other styles

44

Rieger, Samantha M., Daniel J. Scheeres, and Brent Barbee. "Orbital Stability Regions for Hypothetical Natural Satellites of (101955) Bennu." Journal of Spacecraft and Rockets 56, no. 3 (May 2019): 789–800. http://dx.doi.org/10.2514/1.a34160.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Craft, K. L., O. S. Barnouin, R. Gaskell, E. Palmer, J. Weirich, M. Perry, B. Bierhaus, et al. "Assessing stereophotoclinometry by modeling a physical wall representing asteroid Bennu." Planetary and Space Science 193 (November 2020): 105077. http://dx.doi.org/10.1016/j.pss.2020.105077.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Golish, D. R., N. K. Shultz, T. L. Becker, K. J. Becker, K. L. Edmundson, D. N. DellaGiustina, C. Drouet d'Aubigny, et al. "A high-resolution normal albedo map of asteroid (101955) Bennu." Icarus 355 (February 2021): 114133. http://dx.doi.org/10.1016/j.icarus.2020.114133.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Zhang, Yonglong, Xiangyuan Zeng, Christian Circi, and Giovanni Vulpetti. "The motion of surface particles for the asteroid 101955 Bennu." Acta Astronautica 163 (October 2019): 3–10. http://dx.doi.org/10.1016/j.actaastro.2018.11.044.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Ishiguro, Masateru, Yoonsoo P. Bach, Jooyeon Geem, Hiroyuki Naito, Daisuke Kuroda, Myungshin Im, Myung Gyoon Lee, et al. "Polarimetric properties of the near-Sun asteroid (155140) 2005 UD in comparison with other asteroids and meteoritic samples." Monthly Notices of the Royal Astronomical Society 509, no. 3 (November 9, 2021): 4128–42. http://dx.doi.org/10.1093/mnras/stab3198.

Full text

Abstract:

ABSTRACT The investigation of asteroids near the Sun is important for understanding the final evolutionary stage of primitive Solar system objects. A near-Sun asteroid (NSA), (155140) 2005 UD, has orbital elements similar to those of (3200) Phaethon (the target asteroid for the JAXA’s DESTINY+ mission). We conducted photometric and polarimetric observations of 2005 UD and found that this asteroid exhibits a polarization phase curve similar to that of Phaethon over a wide range of observed solar phase angles (α = 20–105°) but different from those of (101955) Bennu and (162173) Ryugu (asteroids composed of hydrated carbonaceous materials). At a low phase angle (α ≲ 30°), the polarimetric properties of these NSAs (2005 UD and Phaethon) are consistent with anhydrous carbonaceous chondrites, while the properties of Bennu are consistent with hydrous carbonaceous chondrites. We derived the geometric albedo, pV ∼ 0.1 (in the range of 0.088–0.109); mean V-band absolute magnitude, HV = 17.54 ± 0.02; synodic rotational period, $T_\mathrm{rot} = 5.2388 \pm 0.0022 \, \mathrm{h}$ (the two-peaked solution is assumed); and effective mean diameter, $D_\mathrm{eff} = 1.32 \pm 0.06 \, \mathrm{km}$. At large phase angles (α ≳ 80°), the polarization phase curve are likely explained by the dominance of large grains and the paucity of small micron-sized grains. We conclude that the polarimetric similarity of these NSAs can be attributed to the intense solar heating of carbonaceous materials around their perihelia, where large anhydrous particles with small porosity could be produced by sintering.

APA, Harvard, Vancouver, ISO, and other styles

49

Nabila Rizadian1, Allysa Faras, Leo Danuarta, Merianty Merianty, Rian Rahmattulloh, and Shadan Aryansyah Putra. "URGENSI MENDAFTARKAN MEREK SUATU PRODUK DALAM USAHA ATAU BISNIS." PROSIDING SERINA 1, no. 1 (December 30, 2021): 2035–44. http://dx.doi.org/10.24912/pserina.v1i1.18079.

Full text

Abstract:

Intellectual Property Rights is something that is protected by law. This mark has been regulated in Law Number 15 of 2001 concerning Trademarks, the owner of the mark will obtain legal protection for his trademark after registering the trademark with the Directorate General of Intellectual Property Rights. Violation of a registered mark will give rise to the rights of the owner of the registered brand name. One example is the use of the name "Bensu" as a trademark, Ruben Onsu sued PT I Am Geprek Benny Sujono for using the word "Bensu" in his trademark.This study aims to determine the importance of registering the brand name of the product to be cultivated, and to understand the extent of protection that can be provided by the Trademark Law that has been registered in Indonesia, and to inform about the legal consequences of violating the Trademark Law. The research method used is normative legal research conducted by collecting primary data and secondary data. Data analysis in this study used qualitative data analysis methods.The results showed that the judges did not see the term "Bensu" as an abbreviation of the name of a famous person. All data has been checked and finally it was found that the name "Bensu" was recorded and recorded by I Am Geprek Bensu by PT I Am Geprek Bensu Benny Sujono on 3 May 2017, while Ruben Onsu registered his trademark name on 7 June 2018. In the end the award decision is the brand "Geprek Bensu" Ruben Onsu as a whole. Hak Kekayaan Intelektual adalah suatu hal yang dilindungi oleh hukum. Perlindungan atas merek ini sudah diatur dalam Undang-Undang Nomor 15 Tahun 2001 Tentang Merek Dagang, Pemilik merek akan memperoleh perlindungan hukum untuk merek dagangnya setelah mendaftarkan merek dagang yang dimilikinya kepada Direktorat Jenderal Hak Kekayaan Intelektual. Pelanggaran atas merek yang sudah terdaftar akan menimbulkan tuntutan hak dari pemilik nama merek yang didaftarkan. Salah satu contoh kasus yakni pemakaian nama “Bensu” sebagai merek dagang, Ruben Onsu menggugat PT I Am Geprek Benny Sujono karena menggunakan kata “Bensu” di merek dagangnya.Penelitian ini bertujuan untuk mengetahui sebagaimana pentingnya untuk mendaftarkan nama merek produk yang akan diusahakan, dan memahami sejauh mana perlindungan yang dapat diberikan oleh Undang-Undang Merek terhadap merek-merek yang telah terdaftar di Indonesia, dan memberitahu mengenai akibat hukum apa saja yang ditimbulkan dari pelanggaran Undang-Undang Merek. Metode Penelitian yang digunakan adalah penelitian hukum normatif yang dilakukan dengan pengumpulan data-data primer dan data-data sekunder. Analisis data dalam penelitian ini menggunakan metode analisis data kualitatif. Hasil penelitian menunjukkan penggunaan merek dagang “Bensu” hakim tidak melihat sebutan “Bensu” sebagai singkatan nama dari orang terkenal. Pada persidangan semua data ditinjau dan akhirnya menemukan bahwa nama dari “Bensu” sudah terdaftar dan didaftarkan dengan I Am Geprek Bensu oleh PT I Am Geprek Bensu Benny Sujono pada 3 Mei 2017, sedangkan Ruben Onsu mendaftarkan nama merek dagangnya pada 7 Juni 2018. Pada akhirnya putusan pengadilan adalah membatalkan merek “Geprek Bensu” Ruben Onsu secara keseluruhan.

APA, Harvard, Vancouver, ISO, and other styles

50

Russell, Ryan P., Demyan Lantukh, and Stephen B. Broschart. "Heliotropic Orbits with Zonal Gravity and Shadow Perturbations: Application at Bennu." Journal of Guidance, Control, and Dynamics 39, no. 9 (September 2016): 1925–33. http://dx.doi.org/10.2514/1.g001279.

Full text

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!