Adaptive optics (AO) has left its infancy and experimental phase. The major telescopes are equipped with mature AO facility instruments. AO has become indispensable for high-resolution astrophysics since a couple of years. Still, data reduction techniques are in the process of evolution (e.g. convolution, PSF reconstruction, photometry), and the reliability of these data (AO artefacts) under discussion. For most astronomical targets, AO generated image data cannot be directly verified. Only space missions to solar-system objects make a direct comparison possible.
In the context of the Cassini/Huygens mission within the ESA coordinated ground-based observation campaign, stunning VLT/NACO data of Titan have been obtained uniquely demonstrating the potential and reliability of modern AO technology. Re-projecting the Cassini/ISS map to the same viewing angle prevailing at the time of NACO AO observations allows us to compare directly the surface details (see figure).
At small angular-size objects as Titan, Pluto, Charon, and the asteroid Vesta, we demonstrate how AO supported ground-based observations combined with sophisticated instrumentation such as Simultaneous Differential Imaging, Fabry-Perot, 3-D spectroscopy have become inalienable to support space missions and to complement their scientific achievements.
