Krypton in the Chassigny meteorite shows Mars accreted chondritic volatiles before nebular gases
Sandrine Péron and Sujoy Mukhopadhyay
Science, 16 Jun 2022
Supplementary Materials (DOWNLOAD)
“Volatile chemical elements are thought to have been delivered to Solar System terrestrial planets late in their formation, by accretion of chondritic meteorites. Mars can provide information on inner Solar System volatile delivery during the earliest planet formation stages. We measured krypton isotopes in the Martian meteorite Chassigny, representative of the planet’s interior. We find chondritic krypton isotope ratios, implying early incorporation of chondritic volatiles. Mars’ atmosphere has different (solar-type) krypton isotope ratios, indicating it is not a product of magma ocean outgassing or fractionation of interior volatiles. Atmospheric krypton instead originates from accretion of solar nebula gas, after the mantle formed, but prior to nebular dissipation. Our observations contradict the common hypothesis that, during planet formation, chondritic volatile delivery occurred after solar gas acquisition.”
