The whole-disk polarization of Uranus was measured over two apparitions in blue and red light. The behavior of the blue polarization as a function of phase angle is indicative of non-Rayleigh scattering. The red polarization phase curve, while not necessarily suggesting Rayleigh scattering, is at least consistent with that interpretation. One explanation of these data is that the blue radiation is scattered by the CH4 haze layer suggested by others for Uranus while red radiation, because of methane absorptions above this layer, does not penetrate to or scatter significantly from this haze layer. There is no whole-disk circular polarization, as expected, confirming other observations and theoretical predictions. In addition, polarization measurements of Comet West were carried out after perihelion. The results indicate that large particles are primarily responsible for the scattering of continuum light.
- Pub Date:
- June 1976
- Uranus (Planet);
- Rayleigh Scattering;
- Lunar and Planetary Exploration