DIRECT SOLUTIONS OF THE MAXWELL EQUATIONS EXPLAIN OPPOSITION PHENOMENA OBSERVED FOR HIGH-ALBEDO SOLAR SYSTEM OBJECTS

Journal Article · Tue Nov 10 00:00:00 EST 2009 · Astrophysical Journal (Online)

DOI:https://doi.org/10.1088/0004-637X/705/2/L118· OSTI ID:21378340

Mishchenko, Michael I; Li, Liu ^[1]; Dlugach, Janna M; Rosenbush, Vera K; Kiselev, Nikolai N ^[2]

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1. NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025 (United States)
2. Main Astronomical Observatory of the National Academy of Sciences of Ukraine, 27 Zabolotny Street, 03680 Kyiv (Ukraine)

Several spectacular backscattering effects observed for particulate planetary surfaces have been interpreted in terms of the effect of weak localization (WL) of electromagnetic waves. However, the interference concept of WL explicitly relies on the notion of phase of an electromagnetic wave and is strictly applicable only when particles forming the surface are widely separated. Therefore, one needs a definitive quantitative proof of the WL nature of specific optical effects observed for densely packed particulate media. We use numerically exact computer solutions of the Maxwell equations to simulate electromagnetic scattering by realistic models consisting of large numbers of randomly positioned, densely packed particles. By increasing the particle packing density from zero to approx40%, we track the onset and evolution of the full suite of backscattering optical effects predicted by the low-density theory of WL, including the brightness and polarization opposition effects (BOE and POE). We find that all manifestations of WL, except the circular polarization ratio and POE, are remarkably immune to packing-density effects. Even POE can survive packing densities typical of planetary regolith surfaces. Our numerical data coupled with the results of unique observations at near-backscattering geometries demonstrate that the BOE and POE detected simultaneously for high-albedo solar system objects are caused by the effect of WL.

• OSTI ID: 21378340
• Journal Information: Astrophysical Journal (Online), Vol. 705, Issue 2; Other Information: DOI: 10.1088/0004-637X/705/2/L118; ISSN 1538-4357
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ALBEDO
ASTEROIDS
BACKSCATTERING
BRIGHTNESS
ELECTROMAGNETIC RADIATION
INTERFERENCE
MATHEMATICAL SOLUTIONS
MAXWELL EQUATIONS
NUMERICAL DATA
PARTICLE TRACKS
PLANETS
POLARIZATION
RADIANT HEAT TRANSFER
SATELLITES
SOLAR SYSTEM
DATA
DIFFERENTIAL EQUATIONS
ENERGY TRANSFER
EQUATIONS
HEAT TRANSFER
INFORMATION
OPTICAL PROPERTIES
PARTIAL DIFFERENTIAL EQUATIONS
PHYSICAL PROPERTIES
RADIATIONS
SCATTERING