The DARWIN space mission aims at detecting the (possible) 1-10
Earth-mass planets around 200 to 300 nearby stars, and perform their
thermal infrared spectroscopy. The goal is to determine their
atmospheric composition. With a spectral resolution of the instrument
(/
) of about 50 and a signal to noise ratio
varying from 5 to 20, the mission has 2 major objectives:
(1)
Exoplanetology, with an attractive possibility of comparing the
properties of these objets to those of the Solar System planets;
(2)
Exobiology by the search for biosignatures that can reveal the presence
of life similar to ours.
Even if one of the first objectives is to
have the mission flying promptly, it makes sense thinking to the "After
DARWIN", although the latter will probably be strongly determined by
the (unexpected) discoveries of DARWIN. We will discuss the merits and
technical requirements of the different possibilities , including:
(1) imaging these planets (e.g. mission such as "Exo Earth Imager";
(2) performing visible-Near IR spectroscopy;
(3) spectroscopy in the
thermal IR at higher resolution, S/N and on a larger stellar sample
("Super DARWIN").
The ultimate goal of searching for indices of technological life will also be discussed.