Seminar

Bulk elemental and isotopic data for martian meteorites demonstrate that key aspects of Marsʼ composition are markedly different from that of Earth. This suggests that Mars formed outside of the terrestrial feeding zone. It is therefore probable that Mars always remained significantly farther from the Sun than Earth; its growth was stunted early and its mass remained relatively low. Here we show a robust dynamical pathway that forms and keeps Mars outside of Earth's accretion zone while at the same time accounting for strict age and compositional constraints, and mass differences. This scenario suggests that Mars' volatile budget is different from Earth's and predicts that Venus formed close enough to our planet that it is expected to have similar composition, including the oxygen isotopes.