Table 2 Composition of silicate shells and metallic cores of the terrestrial planets
From: Terrestrial planet compositions controlled by accretion disk magnetic field
| Â | Mercury a | Earth b | Mars c |
|---|---|---|---|
Bulk silicate shell, atomic% (wt%) | |||
O | 55.30 (42.3) | 58.5 (44.0) | 59.3 (43.2) |
Mg | 25.93 (25.9) | 20.0 (22.8) | 16.9 (18.7) |
Si | 14.6 (19.6) | 15.9 (21.0) | 16.6 (21.3) |
Fe | 0.17 (0.46) | 2.4 (6.3) | 4.5 (11.4) |
Al | 2.1 (2.7) | 1.85 (2.35) | 1.55 (1.90) |
Ca | 1.5 (2.9) | 1.34 (2.53) | 1.13 (2.06) |
S | 4.1 (6.3) | – | – |
Mg# | 0.99 | 0.89 | 0.79 |
Mg/Si | 1.53 (1.32) | 1.26 (1.09) | 1.01 (0.88) |
Al/Si | 0.143 (0.137) | 0.117 (0.11) | 0.0929 (0.089) |
Fe/Si | 0.0118 (0.024) | 0.150 (0.30) | 0.269 (0.54) |
Silicate mass (kg) d | 8.6 ×1022 | 4.04 ×1024 | 5.27 ×1023 |
Core, including an FeS component, atomic% (wt%) | |||
O | – | 6.4 (2.0) | 16 (5.2) |
Si | 7.6 (4.1) | 7.3 (4.0) | – |
Fe | 81 (86) | 78 (86) | 68 (80) |
Ni | 4.4 (4.9) | 4.4 (5.1) | 6.0 (7.4) |
S | 6.0 (3.6) | 3.0 (1.9) | 9.9 (6.6) |