Class M planet

Class M planets is a planetary classification used for planets that are optimal for humanoid life. They are almost always found in the ecozone region of a star's solar system. They have an abundant amount of water and a oxygen/nitrogen atmosphere making it highly suitable for life. Earth is an example of a Class M planet.
Planets with more than 80% surface water fall under Class O or Class P.
==Class M planets==
*List of Class M planets
==References==
Category:Astronomical objects