Namekians live on Kepler 22b.
Observe. This is Kepler 22b.
and this is Namek.
DragonBall Z is always right, they obviously have a more advanced telescope that found Kepler-22b before NASA and discovered the alien race that inhabits it AND THEY CAN FLY.
But in all seriousness I see Kepler-22b as a very fine enforcer that life could easily be inhabiting other planets, yes it looks similar to our world so it is automatically more appealing to us visually, however my speculations are that this planet on the surface is not similar to ours sense its radius is slightly larger than ours therefor the organisms inhabiting this planet (If there are any.) would be slightly diffrent and unable to reach the
exact same similarities of humans even though advanced cognitive abilities could still be attained, unless its age is younger than earths, then I believe the lifeforms are multi-cellular Eukaryotes, but not very advanced such as
Saccharomyces cerevisiae. (This is all speculation of course.)