Evaporite Minerals in Bennu Samples
When
Where
Dr. Tim McCoy
Curator of Meteorites
National Museum of Natural History
Smithsonian
Evaporite minerals have been documented extensively on Earth, as well as on Mars, the dwarf planet Ceres, and the icy moons of Jupiter and Saturn. Despite their widespread occurrence, they are poorly understood outside Earth owing to a lack of samples available for study in laboratories on Earth. We report the occurrence of a variety of evaporite minerals in samples of the asteroid (101955)Bennu returned by the OSIRIS-REx mission. These include sodium-bearing phosphates and sodium-rich carbonates, sulfates, chlorides and fluorides formed during evaporation of a late-stage brine that existed in the earliest history of the Solar System. These minerals are largely unstable in the Earth’s atmosphere, explaining their near absence in analog meteorites recovered after their fall to Earth. These minerals and their associated sodium-rich brine are an ideal environment for formation of complex prebiotic organics that were the first step on the path to life.
Host: Dr. Tom Zega