Sub-surface alteration and related change in reflectance spectra of space-weathered materials

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F22%3A00561082" target="_blank" >RIV/67985831:_____/22:00561082 - isvavai.cz</a>

Alternative codes found

RIV/00216208:11320/22:10453452 RIV/26722445:_____/22:N0000058

Result on the web

<a href="https://www.aanda.org/articles/aa/full_html/2022/09/aa43282-22/aa43282-22.html" target="_blank" >https://www.aanda.org/articles/aa/full_html/2022/09/aa43282-22/aa43282-22.html</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202243282" target="_blank" >10.1051/0004-6361/202243282</a>

Result language

angličtina

Original language name

Sub-surface alteration and related change in reflectance spectra of space-weathered materials

Original language description

Context. Airless planetary bodies are studied mainly by remote sensing methods. Reflectance spectroscopy is often used to derive their compositions. One of the main complications for the interpretation of reflectance spectra is surface alteration by space weathering caused by irradiation by solar wind and micrometeoroid particles.nAims. We aim to evaluate the damage to the samples from H+ and laser irradiation and relate it to the observed alteration in the spectra.nMethods. We used olivine (OL) and pyroxene (OPX) pellets irradiated by 5 keV H+ ions and individual femtosecond laser pulses and measured their visible (VIS) and near-infrared (NIR) spectra. We observed the pellets with scanning and transmission electron microscopy. We studied structural, mineralogical, and chemical modifications in the samples. Finally, we connected the material observations to changes in the reflectance spectra.nResults. In both minerals, H+ irradiation induces partially amorphous sub-surface layers containing small vesicles. In OL pellets, these vesicles are more tightly packed than in OPX ones. Any related spectral change is mainly in the VIS spectral slope. Changes due to laser irradiation are mostly dependent on the material’s melting temperature. Of all the samples, only the laser-irradiated OL contains nanophase Fe particles, which induce detectable spectral slope change throughout the measured spectral range. Our results suggest that spectral changes at VIS-NIR wavelengths are mainly dependent on the thickness of (partially) amorphous sub-surface layers. Furthermore, amorphisation smooths micro-roughness, increasing the contribution of volume scattering and absorption over surface scattering.nConclusions. Soon after exposure to the space environment, the appearance of partially amorphous sub-surface layers results in rapid changes in the VIS spectral slope. In later stages (onset of micrometeoroid bombardment), we expect an emergence of nanoparticles to also mildly affect the NIR spectral slope. An increase in the dimensions of amorphous layers and vesicles in the more space-weathered material will only cause band-depth variation and darkening.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

<a href="/en/project/LM2015093" target="_blank" >LM2015093: Sustainable Energy</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2022

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astronomy & Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Volume of the periodical

665

Issue of the periodical within the volume

September 2022

Country of publishing house

FR - FRANCE

Number of pages

8

Pages from-to

A14

UT code for WoS article

000849631100003

EID of the result in the Scopus database

2-s2.0-85141283889