2010年8月5日星期四

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Christian Louboutin Shoes sale single data set is unambiguous. The conversion of infrared observations (13) into reflectivities that can be compared with laboratory materials is hampered by uncertainties in the absorption by atmospheric methane and the absorption and scattering by the haze. Furthermore, these effects themselves are Christian Louboutin Boots on sale uniform across Titan, which has a strong seasonal cycle. The existence of discrete, time-variable methane clouds beneath the haze poses another challenge to infrared observations.In contrast, radar can penetrate the atmosphere completely, returning an echo from the surface and perhaps the first few meters below it. As when fishermen use polarized sunglasses, surface reflections can be discriminated from subsurface scattering using the Christian Louboutin Sandals sale of the radar echo. Campbell et al. found a low polarization ratio for Titan, suggesting that most of the echo is from surface reflection. In contrast, highly polarized radar echoes have been received from the icy galilean satellites, where subsurface scattering is important.Better signal-to-noise ratios and spatial resolution are needed to make more confident interpretations. The limits of what can be achieved from Earth have essentially been reached. Further christianlouboutin discount can be expected when the Cassini spacecraft makes its first close reconnaissance of Titan in October 2004-the first of more than 40 flybys in its 4-year nominal mission.

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