Abstract: After the discovery of 3 pulsar planets in 1990 the first exoplanet in 1995 (like Jupiter) was the beginning of a remarkable increase of the number of observed extrasolar planets. Nowadays, almost 30 years later, we have knowledge of 3710 planets, 2780 planetary systems and 621 multiple planet systems. 2/3 of these planets are large ones like Superearth, Neptunes and Jupiters in a close distance to the hosting star. Such planets are often refereed as "HOT JUPITERS" and their existence is still not fully understood. But every now and then the discovery of a second Earth is announced - but it always turns out to be a sort of fake news.

    In this seminar I will speak about the techniques to observe extrasolar planets, will also give some details of the first space telescope observing such planets via transits - the European satellite COROT and will speak about possible habitability of terrestrial planets out there in the Universe.