Extrasolar planets : - From gaseous giant planets to rocky planets. - Steps towards the detection of life biomarkers.

<!--HTML--><p>Discoveries done during the last two decades have revealed the impressive diversity of extrasolar planetary systems. A diversity challenging our understanding of&nbsp; mechanisms of formation and evolution.<br /> Today, great efforts are made to detect Earth-mass rocky planets in the so-called habitable zone of their host stars. What are the difficulties, the instrumental projects&nbsp; and the already detected interesting systems ?</p>