Mars and Earth - distinct inner solar system products
Abstract
Terrestrial planets provide solar system insights into the evolution of accretion, core-mantle and mantle-crust differentiation, and surface processes. Our model composition for Mars (cf. Earth), constrained by Martian meteorites and satellite observations, finds that terrestrial planets accreted more high-temperature and less volatile materials than chondritic asteroids from the inner solar system. Mars' depletion in moderately volatile element (but less so than the Earth's) reflects a nebular chemical fractionation and restricts its core to having ~4 wt% (2 wt%) S. The core of Mars (Earth) is small (24% vs 33%), partially molten, and lacking a dynamo, making the planet inhospitable to uninhabitable. Mars' (Earth's) planetary Urey ratio of 0.81 (0.43) reflects limited remaining contributions from secular cooling. These attributes set compositional limits for habitable planets.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.V43D0113Y
- Keywords:
-
- 1009 Geochemical modeling;
- GEOCHEMISTRY;
- 1025 Composition of the mantle;
- GEOCHEMISTRY;
- 1028 Composition of meteorites;
- GEOCHEMISTRY;
- 1060 Planetary geochemistry;
- GEOCHEMISTRY