# How do pressure, temperature, and gravity affect a smaller body than Earth with the same bulk composition?

Earth has a density of about $${\rm 5.513 ~g/cm^3}$$ with one Earth radius and one $$g$$. Venus, a very similar planet to Earth and likely with about the same bulk composition, has a density of about $${\rm 5.24 ~g/cm^3}$$ with 0.95 Earth radii and $$0.9 \cdot g$$. How does this scale? If a planet has 0.5 Earth radii, how would the lower core pressure, lower temperature, and lower gravity impact the density based on the same bulk composition?