Janice R. Andrews
Scientists analyzing samples from asteroid Bennu have discovered preserved salt deposits that offer fresh insights into how life may have emerged in our cosmic neighborhood. The findings, published in Nature and Nature Astronomy, show that Bennu harbored water and contains crucial biological building blocks, including components needed to form DNA and RNA.
The salt deposits found in Bennu’s material contain sodium carbonate and phosphorus, with a unique chemical signature distinct from Earth’s salt formations. This discovery suggests asteroids may have played a key role in distributing life’s fundamental ingredients throughout the solar system. Researchers note similar chemical signatures on Enceladus, Saturn’s moon, and the dwarf planet Ceres – both considered promising sites for potential life.
The pristine samples, gathered by NASA’s OSIRIS-REx spacecraft from Bennu’s surface in 2020, yielded an impressive 121.6 grams of material from the asteroid, located 200 million miles away. Unlike meteorites that have been altered by Earth’s environment, these untainted samples provide direct evidence of conditions in the early solar system.
The discovery of complex organic compounds strengthens the hypothesis that the basic ingredients for life were common in space before Earth formed. Ongoing analysis of the samples continues to reveal new details about how water and life’s building blocks spread throughout the cosmos.
“Finding the unexpected is exploration’s greatest reward,” noted Tim McCoy, curator of meteorites at the Smithsonian and co-lead author of the Nature study. “This discovery exemplifies why we undertake such missions.”
The OSIRIS-REx mission’s achievements highlight the value of studying asteroids to understand both planetary development and life’s cosmic journey. As research continues, Bennu’s samples may fundamentally alter our understanding of humanity’s place in the universe.
