Space weathering effects in Bennu asteroid samplesOPEN ACCESS 

· by · in , , ,

L. P. Keller, M. S. Thompson, L. B. Seifert, L. E. Melendez, K. L. Thomas-Keprta, L. Le, C. J. Snead, K. C. Welten, K. Nishiizumi, M. W. Caffee, J. Masarik, H. Busemann, D. Krietsch, C. Maden, Z. Rahman, C. A. Dukes, E. A. Cloutis, Z. Gainsforth, S. A. Sandford, D. N. DellaGiustina, H. C. Connolly Jr. & D. S. Lauretta

Nature Geoscience (2025)

LINK (OPEN ACCESS)
PDF (OPEN ACCESS)

“The OSIRIS-REx mission deployed contact pad samplers to collect regolith from the uppermost surface of the asteroid Bennu that was exposed to the space environment. Space weathering processes, dominated by micrometeoroid impacts and solar irradiation, modify the mineralogy and chemistry of exposed surfaces to produce solar wind-amorphized layers on clays, metallic whiskers associated with high temperature melts and Fe nitride created by the reaction of indigenous N-bearing gases with space-weathered surfaces. Here, we use cosmogenic noble gases and radionuclides to suggest that the upper metre of Bennu’s regolith has been exposed to cosmic rays for 2–7 million years, consistent with remote sensing observations indicating that the asteroid’s surface is dynamic and regularly modified by mass movement. Solar energetic particle track and microcrater densities constrain the space weathering spectral changes observed in Hokioi crater to <50,000 years. These spectral changes are driven largely by the accumulation of impact melt deposits on particle surfaces, although compositional or grain size effects may also occur. Comparison of Bennu samples with those collected from the asteroids Ryugu and Itokawa suggest that micrometeoroid impacts might play a more active and rapid role in the space weathering of asteroidal surfaces than was initially suggested, particularly for carbonaceous bodies.”

Related posts (automatically generated):

  1. Overview of the search for signs of space weathering on the low-albedo asteroid (101955) BennuOPEN ACCESS 
  2. Diverse space weathering effects on asteroid surfaces as inferred via laser irradiation of meteoritesOPEN ACCESS 
  3. Mid-infrared Measurements of Ion-irradiated Carbonaceous Meteorites: How to Better Detect Space Weathering EffectsOPEN ACCESS 
  4. Comparison of optical spectra between asteroids Ryugu and Bennu: II. High-precision analysis for space weathering trendsOPEN ACCESS 
  5. Space weathering, grain size, and metamorphic heating effects on ordinary chondrite spectral reflectance parametersOPEN ACCESS 
  6. Simulation of Space Weathering on Asteroid Spectra through Hydrogen Ion Irradiation of MeteoritesOPEN ACCESS 
  7. Incipient space weathering on asteroid 162173 Ryugu recorded by pyrrhotiteOPEN ACCESS 
  8. Spectral evolution of dark asteroid surfaces induced by space weathering over a decadeOPEN ACCESS 
  9. Evidence of global space weathering by solar wind on asteroid 162173 Ryugu
  10. Space Weathering of Genesis Mission Solar-wind Collectors with Inferences for Weathering on Airless BodiesOPEN ACCESS 
Tags: , ,