Using mass-radius-composition models, small planets (R≲2R⊕) are typically classified into three types: iron-rich, nominally Earth-like, and those with solid/liquid water and/or atmosphere.
Using mass-radius-composition models, small planets (R≲2R⊕) are typically classified into three types: iron-rich, nominally Earth-like, and those with solid/liquid water and/or atmosphere.