We have obtained spatially resolved spectra of Titan in the near-infrared J, H and K bands at a resolving power of ~5000 using the near-infrared integral field spectrometer (NIFS) on the Gemini North 8m telescope. Using recent data from the Cassini/H
uygens mission on the atmospheric composition and surface and aerosol properties, we develop a multiple-scattering radiative transfer model for the Titan atmosphere. The Titan spectrum at these wavelengths is dominated by absorption due to methane with a series of strong absorption band systems separated by window regions where the surface of Titan can be seen. We use a line-by-line approach to derive the methane absorption coefficients. The methane spectrum is only accurately represented in standard line lists down to ~2.1 {mu}m. However, by making use of recent laboratory data and modeling of the methane spectrum we are able to construct a new line list that can be used down to 1.3 {mu}m. The new line list allows us to generate spectra that are a good match to the observations at all wavelengths longer than 1.3 {mu}m and allow us to model regions, such as the 1.55 {mu}m window that could not be studied usefully with previous line lists such as HITRAN 2008. We point out the importance of the far-wing line shape of strong methane lines in determining the shape of the methane windows. Line shapes with Lorentzian, and sub-Lorentzian regions are needed to match the shape of the windows, but different shape parameters are needed for the 1.55 {mu}m and 2 {mu}m windows. After the methane lines are modelled our observations are sensitive to additional absorptions, and we use the data in the 1.55 {mu}m region to determine a D/H ratio of 1.77 pm 0.20 x 10-4, and a CO mixing ratio of 50 pm 11 ppmv. In the 2 {mu}m window we detect absorption features that can be identified with the { u}5+3{ u}6 and 2{ u}3+2{ u}6 bands of CH3D.
[Abridged] To simulate the kinds of observations that will eventually be obtained for exoplanets, the Deep Impact spacecraft obtained light curves of Earth at seven wavebands spanning 300-1000 nm as part of the EPOXI mission of opportunity. In this p
aper we analyze disc-integrated light curves, treating Earth as if it were an exoplanet, to determine if we can detect the presence of oceans and continents. We present two observations each spanning one day, taken at gibbous phases. The rotation of the planet leads to diurnal albedo variations of 15-30%, with the largest relative changes occuring at the reddest wavelengths. To characterize these variations in an unbiased manner we carry out a principal component analysis of the multi-band light curves; this analysis reveals that 98% of the diurnal color changes of Earth are due to only 2 dominant eigencolors. We use the time-variations of these two eigencolors to construct longitudinal maps of the Earth, treating it as a non-uniform Lambert sphere. We find that the spectral and spatial distributions of the eigencolors correspond to cloud-free continents and oceans; this despite the fact that our observations were taken on days with typical cloud cover. We also find that the near-infrared wavebands are particularly useful in distinguishing between land and water. Based on this experiment we conclude that it should be possible to infer the existence of water oceans on exoplanets with time-resolved broadband observations taken by a large space-based coronagraphic telescope.
