Note that material entities may have immaterial entities (e.g. sites) as parts.

This class includes material parts of astronomical bodies. Immaterial parts, such as magnetospheres, are represented as sites under the influence of magnetic fields.Please post countercases in the ENVO tracker for revision of this hierarchy if needed.

Also note that some astronomical body parts (ABPs) may have fiat boundaries: if there's strong debate about where an ABP begins or ends (over and above fuzzy boundaries), with different official classifications setting different thresholds or limits, axiomatise the class with fiat boundaries of the appropriate dimension.