Dr. Danny Glavin, a senior scientist at NASA, and Dr. Dante Lauretta, a planetary scientist leading the OSIRIS-REx mission, delve into the groundbreaking findings from asteroid Bennu. They discuss the discovery of organic molecules and essential amino acids that could suggest origins of life. The fascinating chirality of amino acids challenges previous theories. They also highlight the meticulous efforts to prevent sample contamination, revealing significant implications for understanding life's building blocks and the search for extraterrestrial life.
The OSIRIS-REx mission successfully retrieved and analyzed samples from asteroid Bennu, revealing crucial organic molecules that may inform the origins of life.
Discoveries of evaporite minerals suggest Bennu likely emerged from a wetter environment, enhancing the understanding of asteroids as potential life-sustaining bodies.
Deep dives
Significance of the OSIRIS-REx Mission
The OSIRIS-REx mission aimed to collect samples from the near-Earth asteroid Bennu, considered a potentially hazardous asteroid. This mission was designed not only to retrieve material but also to analyze its organic compounds, which date back over four billion years, offering insights into the early solar system. Researchers collected about 120 grams of asteroid material, which exceeded their initial goals and is deemed a valuable resource for extensive scientific analysis in the future. The mission was a culmination of over two decades of efforts to understand the origins of life and the significance of carbon-rich asteroids.
Discoveries from Bennu's Samples
Analysis of the Bennu samples revealed a complex mixture of nearly 10,000 nitrogen-bearing organic molecules, including 14 of the 20 amino acids essential for life on Earth. This finding is significant because these compounds were preserved in a pristine state, unlike previous detections in meteorites that had suffered contamination. The presence of these organic molecules supports the hypothesis that asteroids like Bennu could provide critical building blocks necessary for life. Moreover, researchers identified evaporite minerals indicative of past interactions with saline water, suggesting that Bennu may have originated from a wetter environment.
Implications for Astrobiology and Life's Origins
The discoveries concerning Bennu's organic compounds challenge existing theories about the origin of life, suggesting these materials could have contributed to life on Earth and possibly elsewhere in the solar system. While evidence of current biological activity was not found, the presence of these building blocks opens doors for further exploration into environments like Mars and icy moons, where similar ingredients might exist. The findings establish a baseline for distinguishing abiotic processes from those influenced by biology, which could be pivotal for future missions. Scientists express optimism that continued research on these samples might reveal more about life's origins within our lifetimes.
About four and a half years ago, a spacecraft called OSIRIS-REx touched down on the surface of an asteroid called Bennu. It drilled down and scooped up samples of rock and dust and, after several years of travel, delivered those samples back to Earth.
Since then, researchers around the world have been analyzing tiny bits of that asteroid dust, trying to tease out as much information as they can about what Bennu is like and where it might have come from. Two scientific papers published this week give some of the results of those experiments. Researchers found minerals that could have arisen from the drying of an icy brine, and a soup of organic molecules, including ammonia and 14 of the 20 amino acids necessary for life on Earth.
Dr. Danny Glavin and Dr. Dante Lauretta join Flora Lichtman to talk about the samples, what their analysis is revealing, and what those findings could mean for the hunt for life elsewhere in the solar system.
Transcripts for each segment will be available after the show airs on sciencefriday.com.