Mars

The fourth planet from the sun, Mars was once home to the Martian species but after H'ronmeer's Curse decimated both Green Martian and White Martian alike during their civil war, J'onn J'onzz would have shared that same fate had he not be teleported to Earth where he lived for nearly 30 years.

After failing to several deaths during a attempted invasion by one of Darkseid's minions, J'onn J'onzz exiled himself back to Mars where he expected to die only to discover White Martians that had survived the war, after realising they were not the same kind who had slaughter his people, he began to establish a new home with them.

Decades later aliens would come to Mars to live in it's peaceful colony while J'onn continued as both a leader and a teacher. Of the kinds of alien that came there were Saturnians, Katarthans, and even Kryptonians

K'al J'onzz and M'yri'ah M'gnn are both from this new colony.