Saturn
The first spectro-saturnography was taken in the 3rd March 2007, after the total lunar eclipse. The movie bellow show the narrowband image (3.4 Å) of Saturn at right, above the wavelength of the image , and at left the ratio between that image and the average of all wavelengths (broad band image). The procedure is described in the page of spectro-selenography. In the left image the details are grey when there is no difference between the narrowband image and the broadband image, details are white when they are brighter in the narrowband image, and are black when they are darker. In the movie bellow, the Saturn's disk almost vanish at 620nm and 730nm whereas the rings remain visible. These wavelengths correspond to Methane lines. The solar light penetrates a certain depth in the saturnine atmosphere and the Methane in there absorbs the wavelengths above mentioned, while solar light is simply reflected by the rings where there is no Methane. This explains the vanishing disk, remaining bright the rings.
