Overview
- Researchers mapped a Bennu grain at 20-nanometer resolution and found three distinct chemical domains: aliphatic-rich, carbonate-rich, and nitrogen-bearing organic-rich.
- The clean boundaries between these zones indicate that water moved through restricted channels rather than soaking the rock evenly.
- Fragile aliphatic compounds and nitrogen-bearing organics persist in dry pockets, while organosulfur compounds are confined to carbonate-rich areas formed from water-driven mineral growth.
- The work, led by Mehmet Yesiltas and published in PNAS, used nanoscale infrared and Raman spectroscopy on sample OREX-800066-3 without exposing it to air.
- With about 121 grams of pristine Bennu material on hand, teams plan isotopic dating and temperature tests to time the fluid events and to compare Bennu’s pattern with Ryugu samples and carbonaceous meteorites.