Exoplanets are by definition outside our solar system. By measuring changes in the luminosity of stars, we can deduce the presence and characteristics of any accompanying planets. Given the large number of existing galaxies and the large number of stars they contain, the search for these exoplanets or extrasolar planets, is endless. What are the biosignatures (indicators of life), which will reveal the presence of life on distant exoplanets? | | How to find oxygen, ozone, methane, carbon dioxide and other gases? When the light is polarized, components of the electric field and magnetic field have a specific orientation. In the non-polarized light, the orientation field is random and has no preferred direction. How to detect life on exoplanets? The answer is very original, life is reflected on the Moon. | | The light of life a particularity, a biosignature if observed indirectly reflected on a star neighbor. The objects are exoterres covered with a crust having a radius between 2.5 and 20 times that of the earth and evolving within the habitability area of the parent star. There is nothing surprising in that there are many more planets than stars in our galaxy, but some float freely. |