In the galaxy there are over 400 billion stars. NASA researchers therefore began to sort, looked at stars comparable to the Sun, and those with the same energy flow. They then looked at stars that were neither too old nor too young and, with the Kepler Space Telescope, spotted stars that had planets orbiting them. If they are at the right distance, they are habitable.
Habitable, but are they livable? “Living according to our criteria”, underlines Jean-Christophe Batteria, our journalist on set. They have a ground temperature between 0 and 100 ° C. They possibly have liquid water and if they have a good mass, they can retain an atmosphere which retains water vapor. “This is the start of everything”, explains Jean-Christophe Batteria.