Martians Immigrate to Alien Planets

After the core of Mars cooled, the magnetic field disappeared. After the Martian atmosphere lost the protection of the magnetic field, most of the Martian atmosphere was blown away by solar wind and cosmic rays. The thin atmosphere was unable to sustain the survival of Martians on the surface of Mars. , They had to dig a cave deep enough under Mars to prevent meteorites from impacting, and move to deep underground caves to survive. In order not to survive in caves, the Martians decided to immigrate to alien planets and began to search for alien planets suitable for life...