Composition and exposure age of the Apollo 16 Cayley and Descartes regions from Clementine data: Normalizing the optical effects of space weathering

1996 ◽  
Vol 101 (E1) ◽  
pp. 2225-2234 ◽  
Author(s):  
Erich M. Fischer ◽  
Carlé M. Pieters
Keyword(s):  
Space Weathering ◽  
Exposure Age ◽  
Optical Effects

Characterization of the craters’ surface at Ryugu using NIR spectroscopy

2021 ◽  
Author(s):  
Lucie Riu ◽  
Cédric Pilorget ◽  
Ralph Milliken ◽  
Kohei Kitazato ◽  
Tomoki Nakamura ◽  
...  
Keyword(s):  
Near Infrared ◽  
Spectral Characteristics ◽  
Solar Heating ◽  
Absorption Feature ◽  
Space Weathering ◽  
Near Surface ◽  
Exposure Age ◽  
Reflectance Factor ◽  
Subsurface Material ◽  
Band Depth

<div> <p>Asteroid Ryugu was observed up close for almost a year and a half by the instruments on-board the Japanese Aerospace eXploration Agency (JAXA) Hayabusa2 spacecraft. It has been shown that in the near-infrared wavelength ranges, the asteroid exhibits relatively homogeneous spectral characteristics: including a very low reflectance factor, a slight red slope towards longer wavelengths, and a narrow and weak absorption feature centered at 2.72 <span>μ</span>m. Numerous craters have been identified at the surface of Ryugu. These features provide good candidates for studying more recently exposed near-surface material to further assess potential spectral/compositional heterogeneities of Ryugu. We present here the results of a spectral survey of all previously identified and referenced craters (Hirata et al. 2020) based on reflectance data acquired by the NIRS3 spectrometer. Globally, we find that the spectral properties inside and outside of craters are very similar, indicating that subsurface material is either compositionally similar to material at the surface that has a longer exposure age or that material at Ryugu’s optical surface is spectrally altered over relatively short timescales by external factors such as space weathering. The 2.72 <span>μ</span>m band depth, present on the overall surface, exhibits a slight anti-correlation with the reflectance factor selected at 2 <span>μ</span>m, which could indicate different surface properties (<em>e.g.</em>, grain size and/or porosity) or different alteration processes (<em>e.g.</em>, space weathering, shock metamorphism and/or solar heating). We identified four different spectral classes based on their reflectance factor at 2 <span>μ</span>m and 2.72 <span>μ</span>m absorption strength. The most commonly spectral behavior associated with crater floors, is defined by a slightly lower reflectance at 2 <span>μ</span>m and deeper band depth. These spectral characteristics are similar to those of subsurface material excavated by the Hayabusa2 small carry-on impactor (SCI) experiment, suggesting these spectral characteristics may represent materials with a younger surface exposure age. Conversely, these materials may have experienced significant solar heating and desiccation to form finer grains that subsequently migrated towards and preferentially accumulated in areas of low geopotential, such as craters floors. Detailed analyses of the returned samples of Ryugu that are now being investigated at the curation facility in ISAS will allow for further testing of these formation and alteration hypotheses.<span> </span></p> </div>

scholarly journals An experimental approach to understanding the optical effects of space weathering

Icarus ◽  
2007 ◽  
Vol 192 (2) ◽  
pp. 629-642 ◽  
Author(s):  
Sarah K. Noble ◽  
Carlé M. Pieters ◽  
Lindsay P. Keller
Keyword(s):  
Experimental Approach ◽  
Space Weathering ◽  
Optical Effects

Optical effects of space weathering: The role of the finest fraction

1993 ◽  
Vol 98 (E11) ◽  
pp. 20817 ◽  
Author(s):  
C. M. Pieters ◽  
E. M. Fischer ◽  
O. Rode ◽  
A. Basu
Keyword(s):  
Space Weathering ◽  
Optical Effects

BORATE SOIL CONCENTRATIONS AS AN EXPOSURE AGE CHRONOMETER IN ANTARCTIC BLUE ICE MORAINES

2016 ◽  
Author(s):  
Joseph Graly ◽  
◽  
Kathy Licht ◽  
Michael R. Kaplan
Keyword(s):  
Exposure Age

Second-order optical effects in organometallic nanocomposites induced by an acoustic field

2005 ◽  
Vol 71 (3) ◽  
Author(s):  
A. Migalska-Zalas ◽  
B. Sahraoui ◽  
I. V. Kityk ◽  
S. Tkaczyk ◽  
V. Yuvshenko ◽  
...  
Keyword(s):  
Acoustic Field ◽  
Second Order ◽  
Optical Effects

scholarly journals Coordinated analysis of space weathering characteristics in lunar samples to understand water distribution on the Moon

2021 ◽  
Vol 27 (S1) ◽  
pp. 2260-2262
Author(s):  
Alexander Kling ◽  
Michelle Thompson ◽  
Jennika Greer ◽  
Philipp Heck
Keyword(s):  
Water Distribution ◽  
Space Weathering ◽  
The Moon ◽  
Lunar Samples
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