A mere 60gm of sample - from the 4.5bn-year-old asteroid Bennu – brought to Earth by Nasa recently has caused substantial excitement among scientists and space buffs. The initial studies show evidence of high-carbon content and water, which together could indicate that the building blocks of life on Earth may be found in the rock.
Nasa made the announcement last Wednesday from Johnson Space Centre in Houston where the asteroid material was showed off for the first time since it landed in September. This finding was part of a preliminary assessment of Nasa’s OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification and Security – Regolith Explorer) science team.
“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. “Nasa missions like OSIRIS-REx will improve our understanding of asteroids that could threaten Earth while giving us a glimpse into what lies beyond.”
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 the 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 Earth.
Curation experts at Nasa Johnson, working in new clean rooms built especially for the mission, have carefully disassembled 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, director, Nasa Johnson. “We’ve had scientists and engineers working side-by-side for years to develop specialised 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.
“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, University of Arizona, Tucson. “The bounty of carbon-rich material and the abundant presence of water-bearing clay minerals are just the tip of the cosmic iceberg. With each revelation from Bennu, we draw closer to unravelling the mysteries of our cosmic heritage.”
For the next two years, the mission’s science team will continue characterising the samples and conduct 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 programme, a cohort of more than 200 scientists around the world will explore the Regolith’s properties, including researchers from many US institutions, Nasa partners Japan Aerospace Exploration Agency, Canadian Space Agency, and other scientists from around the world. OSIRIS-REx is the third mission in Nasa’s New Frontiers Programme.