Titan's atmosphere is dense (1,5x earth) and described as a opaque smog. Is it possible, despite that, to see something? Or it's the same problem than with Venus surface? I know there are radar & IR captures but 1) is it enough for observe precisely? 2) can't we do see anything in the visible domain? Maybe Cassini's camera was not "modern" enough?
Cassini's Imaging Science Subsystem produced images like this:
which has a resolution of about 200 m/pixel. This is a near-IR image.
In visible light, color enhancement can bring out some detail:
In UV, the atmosphere is opaque again:
The ISS spans IR, visible and UV light:
Each camera is outfitted with a large number of spectral filters which, taken together, span the electromagnetic spectrum from 2000 Angstroms to 1.1 microns.
Maybe Cassini's camera was not "modern" enough?
an opaque atmosphere will remain opaque no matter what optics you point at it. Cassini provided massively better images than Voyager by using a camera that works at wavelengths where the atmosphere is less opaque.
Cassini also carried a mapping radar which provided a lot of detail.
Cassini's Visual and Infrared Imaging System produced these global views of surface chemical compositions (determind via spectrometry), with infrared light. The colors are not colors that would becseen by the eye but markers for different chemical composition. Orange represents hydrocarbon dunes, blue and purple colirs suggest more water ice.
Thanks to Cassini, which studied Saturn and its rings and moons for thirteen years, Titan was extensively mapped and analysed. One result is this stunning sequence of images created using data acquired by Cassini’s Visual and Infrared Mapping Spectrometer (VIMS), whose infrared observations peered through Titan’s atmosphere, complementing the views obtained by Huygens during descent and on the surface. The maps combine data from the multitude of different observations made under a wide variety of illumination and viewing conditions over the course of the mission, stitched together in a seamless mosaic to provide the best representation of Titan’s surface to date.
The colours reflect variations in materials on the moon’s surface. For example, the moon’s equatorial dune fields appear a consistent brown colour, while bluish and purple hues may indicate materials enriched in water ice.
The image was first published in July 2018 – read more here about how the image was created, and enjoy a video featuring further stunning visuals here. The complete Cassini VIMS data archive of Saturn’s satellites is available here.