Asteroid Bennus exceptional surface. Credit: NASAs Goddard Space Flight Center
Asteroid Bennus boulder-covered surface area offers it defense against small meteoroid effects, according to observations of craters by NASAs OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer) spacecraft. OSIRIS-REx traveled to near-Earth asteroid Bennu and is bringing a little sample back to Earth for research study.
” These observations provide new insight into how asteroids like Bennu react to energetic effects,” said Edward (Beau) Bierhaus of Lockheed Martin Space, Littleton, Colorado, lead author of a paper published in this months concern of Nature Geoscience.
Bennu is a “rubble-pile” asteroid, suggesting that it formed from the particles of a much bigger asteroid that was ruined by an ancient effect. Pieces from the collision coalesced under their own weak gravity to form Bennu.
The team utilized extraordinary, high-resolution international data sets to analyze craters on Bennu: images from the OSIRIS-REx Camera Suite and surface-height information (topography) obtained from the OSIRIS-REx Laser Altimeter, a laser-ranging (lidar) instrument on the spacecraft.
This image reveals asteroid Bennus boulder-covered surface area. It was taken by the PolyCam camera on NASAs OSIRIS-REx spacecraft on April 11, 2019, from a distance of 2.8 miles (4.5 km). The field of vision is 211 feet (64.4 m), and the large stone in the upper right corner of the image is 50 feet (15.4 m) tall. When the image was taken, the spacecraft was over the southern hemisphere, pointing PolyCam far north and to the west. Credit: NASA/Goddard/University of Arizona
” Measuring craters and their population on Bennu was remarkably exciting,” said David Trang of the University of Hawaii at Mānoa, Honolulu, a co-author of the paper. “At Bennu, we found something unique to rocky and little bodies, which expanded our understanding of effects.”
Planetary researchers can estimate the age of surface areas by measuring the abundance and sizes of craters. Impact craters accumulate in time, so a surface with lots of craters is older than a surface with couple of craters. The size of the crater depends on the size of the impactor, with bigger impactors generally making bigger craters. Due to the fact that little meteoroids are much more abundant than big meteoroids, celestial things like asteroids generally have much more small craters than large ones.
Bennus bigger craters follow this pattern, with the number of craters decreasing as their size boosts. For craters smaller than about 6.6 to 9.8 feet (around 2– 3 meters) in size, the trend is backwards, with the number of craters reducing as their size reduces. This shows something unusual is occurring on Bennus surface.
The researchers think that Bennus profusion of boulders acts as a guard, preventing lots of little meteoroids from forming craters. Instead, these impacts are most likely to break apart the stones or chip and fracture them. Likewise, some impactors that do make it through the stones make smaller craters than they would if Bennus surface area was covered in smaller sized, more uniform particles, like beach sand.
This activity causes the surface of Bennu to alter differently than things with solid or fine-grained surfaces. “The displacement or interruption of a individual or little group of stones by a small impact is probably one of the most fast-acting processes on a rubble-pile asteroids surface area. On Bennu, this contributes to making the surface appear to be many times younger than the interior,” said Bierhaus.
Recommendation: “Crater population on asteroid (101955) Bennu shows impact armouring and a young surface area” by E. B. Bierhaus, D. Trang, R. T. Daly, C. A. Bennett, O. S. Barnouin, K. J. Walsh, R.-L. Ballouz, W. F. Bottke, K. N. Burke, M. E. Perry, E. R. Jawin, T. J. McCoy, H. C. Connolly Jr., M. G. Daly, J. P. Dworkin, D. N. DellaGiustina, P. L. Gay, J. I. Brodbeck, J. Nolau, J. Padilla, S. Stewart, S. Schwartz, P. Michel, M. Pajola and D. S. Lauretta, 7 April 2022, Nature Geoscience.DOI: 10.1038/ s41561-022-00914-5.
More about the mission and group:.
The research was supported by NASA under the New Frontiers Program and the OSIRIS-REx Participating Scientist Program, the Canadian area company, the French area firm, the Italian space company, the European Unions Horizon 2020 research and innovation program, and the Academies of Excellence of the Initiative D Excellence Joint, Excellent and Dynamic Initiative of Université Côte dAzur.
The University of Arizona likewise leads the OSIRIS-REx science group and the missions science observation preparation and data processing, and constructed the OSIRIS-REx Camera Suite. NASAs Goddard Space Flight Center in Greenbelt, Maryland, supplies overall objective management, systems engineering, and security and mission guarantee for OSIRIS-REx. OSIRIS-REx is the 3rd objective in NASAs New Frontiers Program, handled by NASAs Marshall Space Flight Center in Huntsville, Alabama, for the companys Science Mission Directorate at NASA Headquarters in Washington, D.C.
Asteroid Bennus boulder-covered surface area gives it defense versus small meteoroid effects, according to observations of craters by NASAs OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer) spacecraft. OSIRIS-REx took a trip to near-Earth asteroid Bennu and is bringing a little sample back to Earth for research study. Bennus larger craters follow this pattern, with the number of craters decreasing as their size boosts. The researchers think that Bennus profusion of stones acts as a shield, avoiding lots of small meteoroids from forming craters. Some impactors that do make it through the boulders make smaller craters than they would if Bennus surface was covered in smaller sized, more consistent particles, like beach sand.
