An evaporite sequence from ancient brine recorded in Bennu samples

Abstract Evaporation or freezing of water-rich fluids with dilute concentrations of dissolved salts can produce brines, as observed in closed basins on Earth 1 and detected by remote sensing on icy bodies in the outer Solar System 2,3 . The mineralogical evolution of these brines is well understood in regard to terrestrial environments 4 , but poorly constrained for extraterrestrial systems owing to a lack of direct sampling. Here we report the occurrence of salt minerals in samples of the asteroid (101955) Bennu returned by the OSIRIS-REx mission 5 . These include sodium-bearing phosphates and sodium-rich carbonates, sulfates, chlorides and fluorides formed during evaporation of a late-stage brine that…

• SI
  Smithsonian Institution
• UD
  U.S. Department of Energy

  Award: 89233218CNA000001
• NA
  National Aeronautics and Space Administration

  Awards: 89233218CNA000001, 80NSSC22K1692, NNH09ZDA007O, NNM10AA11C
• UR
  UK Research and Innovation

  Award: MR/T020261/1
• NS
  Nuclear Safety and Security Commission
• NN
  National Nuclear Security Administration

  Award: 89233218CNA000001
• JS
  Johnson Space Center
• CS
  Canadian Space Agency
• SA
  Science and Technology Facilities Council

  Awards: ST/V000675/1, MR/T020261/1, ST/V000675/1, ST/Y000188/1
• LA
  Los Alamos National Laboratory

  Award: 89233218CNA000001