Recent analyses of samples from the asteroid Bennu have unveiled the presence of essential building blocks for life, shedding light on the origins of life on Earth. The findings, published in two studies on January 30, 2025, stem from just 120 grams of material collected by NASA's OSIRIS-REx spacecraft in 2020.
The samples, returned to Earth in 2023, contained evidence of high carbon content and water. New research indicates that evaporated water from Bennu's parent asteroid left behind crucial organic compounds. Tim McCoy, curator of meteorites at the Smithsonian's National Museum of Natural History and co-lead author, stated, "We have discovered that next step on a pathway to life."
Bennu is believed to have formed approximately 65 million years ago from debris of a parent asteroid that dates back 4.5 billion years. The study suggests that Bennu's parent asteroid once harbored liquid water, which evaporated, leaving a mixture of salts and minerals, some of which have not been previously identified in outer space samples.
Additionally, the analysis suggests a non-terrestrial origin for these compounds, potentially supporting theories that life on Earth may have been seeded from outer space. Yasuhito Sekine from the Institute of Science Tokyo noted that the samples provide unprecedented insight into solar system formation processes.
Researchers are investigating whether similar briny environments exist on other celestial bodies, such as the dwarf planet Ceres and Saturn's moon Enceladus. Nick Timms from Curtin University commented on the implications for the potential existence of life in icy bodies beyond Bennu.
Despite these revelations, many questions about the origins of life remain unanswered. McCoy emphasized the importance of understanding how far the environmental conditions on Bennu could have allowed life to progress. Sara Russell, co-lead author and cosmic mineralogist, highlighted the significant advances made in understanding the evolutionary history of asteroids like Bennu and their role in making Earth habitable.