Radius, mass density and interior structure of terrestrial bodies

Radius, mass density and interior structure of terrestrial bodies

Fig. 6.17 . Mercury is an anomaly in this comparison of size and mean mass density. Mercury is just slightly bigger than the Moon and a little smaller than Mars, but its mean mass density is comparable to that of the larger terrestrial planets, Earth and Venus. As shown in the internal cross sections, Mercury's unexpectedly large mass density is due to a large dense core extending up to 75 percent of its radius. The Moon's core occupies just 20 percent of its radius. The Earth's inner and outer core take up 55 percent of its radius, while that of Mars is smaller.

Copyright 2010, Professor Kenneth R. Lang, Tufts University