As I write this, 4.604 exoplanets are detected, wow! Unfortunately though, probably not one possible candidate for extraterrestrial life. What a weird collection of planetary situations! Those few planets that are in the habitable zone, are so close to their star, that the radiation pressure (f.i. x-ray) probably is too extreme. How big should the magnetic field then be? And how likely is it that a such a magnetic field is established? Of course, compared with the total amount of stars and probable planets in our galaxy, what we have here is a percentage of a percentage of a percentage.