We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Inferring asteroid surface properties from radar albedos and circular-polarization ratios.
- Authors
Virkki, A.; Muinonen, K.; Penttilä, A.
- Abstract
We model electromagnetic scattering from varying closely packed random aggregates of spheres imitating piles of rocks on the surface of an asteroid. We utilize the Multiple Sphere T-Matrix Method software to study how different parameters affect the radar albedo and the circular-polarization ratio, for example, the size distribution and electric permittivities of the spherical particles forming the aggregates, and to see if the computed radar albedos and circular-polarization ratios can be linked to the observational data of asteroids detected using radar. The results of the simulations show the radar albedo and the circular-polarization ratio as a function of size parameter for different silicate minerals, including anorthosite, peridotite olivine, and basalt. A direct vacuum-rock surface interface will be considered as well as an approximation for a case in which the rocks are covered by a layer of powdered material, that is, fine regolith. The promising results show values on the range of observed values and imply that the highest circular-polarization values ( μc > 1) are measurable only for targets with surface material of high electric permittivity (ε′ > 4.0). However, the asteroid surface model requires further development before more robust conclusions can be made of the surface chemical and structural composition.
- Subjects
CIRCULAR polarization; ASTEROIDS; ALBEDO; ELECTROMAGNETIC wave scattering; ROCKS; PARTICLE size distribution; PERMITTIVITY
- Publication
Meteoritics & Planetary Science, 2014, Vol 49, Issue 1, p86
- ISSN
1086-9379
- Publication type
Article
- DOI
10.1111/maps.12161