The 3.5- Micron Polarization of Mercury
Abstract
The polarization of the thermal radiation emitted by Mercury at 3.5 microns was measured through a 4 arc sec aperture on three dates representing two different combinations of phase angle and heliocentric longitude. When fit by a thermal model of the subsurface which takes surface roughness into account, the large measured polarization requires a value of the dielectric constant larger than 2.7 at 3.5 microns with best values around 4.0. These data, together with the smaller values of the dielectric constant derived at longer wavelengths, suggest a surface material, like sand, scree, or talus, which is loosely packed on a scale of centimeters or meters, but compact on a scale of microns.
- Publication:
-
Icarus
- Pub Date:
- October 1975
- DOI:
- 10.1016/0019-1035(75)90084-6
- Bibcode:
- 1975Icar...26..243L
- Keywords:
-
- Infrared Radiation;
- Mercury (Planet);
- Planetary Radiation;
- Polarized Light;
- Thermal Radiation;
- Astronomical Models;
- Optical Polarization;
- Permittivity;
- Phase Shift;
- Surface Roughness Effects;
- Surface Temperature