Planetary Packaging: Mean Densities

Abstract

An important clue to the nature of any celestial object is how it is packaged—its mass per total volume, or mean density, < δ > ¹This is well illustrated by the example of a pulsar, the mean density of which is a colossal 10¹⁷ kg/m³, or 10¹⁴ g/cm³. Water has a mean density of only 1 g/cm³, and the densest materials with which we are familiar have densities of up to ∼ 20 g/cm³. The high densities found in the pulsars must be interpreted in terms of atomic nuclei densities—hence the origin of the “neutron star” designation.