Initial studies of the 4.5-billion-year-old asteroid Bennu sample collected in space and brought to Earth by NASA's University of Arizona-led OSIRIS-REx mission show evidence of water and high-carbon content, which together could indicate the building blocks of life on Earth may be found in the rock.

NASA announced the finding Wednesday from its Johnson Space Center in Houston, where leadership and scientists showed off the asteroid material for the first time since it landed in the Utah desert on Sept. 24. The finding was part of a preliminary assessment of the OSIRIS-REx science team.

"As we peer into the ancient secrets preserved within the dust and rocks of asteroid Bennu, we are unlocking a time capsule that offers us profound insights into the origins of our solar system," said Dante Lauretta, OSIRIS-REx principal investigator and UArizona Regents Professor of Planetary Sciences. "The bounty of carbon-rich material and the abundant presence of water-bearing clay minerals are just the tip of the cosmic iceberg. These discoveries, made possible through years of dedicated collaboration and cutting-edge science, propel us on a journey to understand not only our celestial neighborhood but also the potential for life's beginnings. With each revelation from Bennu, we draw closer to unraveling the mysteries of our cosmic heritage."

One of the core questions driving the mission is understanding the origin of Earth as a habitable planet, Lauretta said, and the current understanding of what makes a world habitable is abundant liquid water on the surface, such as the Earth's oceans and freshwater supplies.

"When Earth formed, especially after the giant impact that spun off the moon, the water and carbon were lost from our planet, so we're looking to figure out, 'How did we get that material back?'" Lauretta added. "Our leading hypothesis is that asteroids rich in carbon and water came in later and delivered the essential building blocks of life, made the Earth a habitable world and the rest is history."

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Although more work is needed to understand the nature of the carbon compounds found, the initial discovery bodes well for future analyses of the asteroid sample. The secrets held within the rocks and dust from the asteroid will be studied for decades to come, offering insights into how our solar system was formed, how the precursor materials to life may have been seeded on Earth, and what precautions need to be taken to avoid asteroid collisions with our home planet.

"The OSIRIS-REx sample is the biggest carbon-rich asteroid sample ever delivered to Earth and will help scientists investigate the origins of life on our own planet for generations to come," said NASA Administrator Bill Nelson. "Almost everything we do at NASA seeks to answer questions about who we are and where we come from. NASA missions like OSIRIS-REx will improve our understanding of asteroids that could threaten Earth while giving us a glimpse into what lies beyond. The sample has made it back to Earth, but there is still so much science to come – science like we've never seen before."  

Bonus sample material

The goal of the OSIRIS-REx sample collection was 60 grams of asteroid material. Curation experts at NASA Johnson, working in new clean rooms built especially for the mission, have spent 10 days so far carefully disassembling the sample return hardware to obtain a glimpse at the bulk sample within. When the science canister lid was first opened, scientists discovered bonus asteroid material covering the outside of the collector head, canister lid and base. There was so much extra material it slowed down the careful process of collecting and containing the primary sample.

"Our labs were ready for whatever Bennu had in store for us," said Vanessa Wyche, NASA Johnson director. "We've had scientists and engineers working side-by-side for years to develop specialized gloveboxes and tools to keep the asteroid material pristine and to curate the samples so researchers now and decades from now can study this precious gift from the cosmos."

Within the first two weeks, scientists performed "quick-look" analyses of that initial material, collecting images from a scanning electron microscope, infrared measurements, X-ray diffraction and chemical element analysis. X-ray computed tomography was also used to produce a 3D computer model of one of the particles, highlighting its diverse interior. This early glimpse provided the evidence of abundant carbon and water in the sample.

For the next two years, the mission's science team will continue characterizing the samples and conducting the analysis needed to meet the mission's science goals. NASA will preserve at least 70% of the sample at Johnson for further research by scientists worldwide, including future generations of scientists.

As part of OSIRIS-REx's science program, a cohort of more than 200 scientists around the world will explore the regolith's properties, including researchers from many U.S. institutions, NASA partners at the Japan Aerospace Exploration Agency, the Canadian Space Agency, and other scientists from around the world. Additional samples will also be loaned later this fall to the Smithsonian Institution, Space Center Houston, and UArizona's Alfie Norville Gem & Mineral Museum.