CAPE CANAVERAL, Fla. — Results from NASA’s recent asteroid sample collection reveal not only the fundamental building blocks for life but also evidence of an ancient watery environment, according to scientists’ announcements on Wednesday.
These discoveries strongly suggest that asteroids could have played a crucial role in seeding life on our planet, offering intricate relationships between these materials and water from their inception.
Tim McCoy from the Smithsonian Institution, a leading author of the study, emphasized the importance of such environments for the evolution of life, indicating that they might have been vital in the transition from simple elements to life itself.
Nasa’s Osiris-Rex spacecraft successfully retrieved about 122 grams (approximately 4 ounces) of dust and small rocks from the near-Earth asteroid Bennu. Upon returning to Earth in 2023, it deposited its sample canister in the Utah desert before heading off for further explorations of another asteroid. This represents the largest collection of extraterrestrial material sourced from beyond the moon, surpassing previous sample missions conducted by Japan, which gathered much less.
The studies featured in the journals Nature and Nature Astronomy utilized samples from Bennu’s dark grains, remnants from the solar system’s inception 4.5 billion years ago. These samples revealed sodium-rich minerals, confirmed amino acids, and nitrogen in the form of ammonia, along with elements of the genetic code.
Notably, the delicate salts identified at Bennu are akin to those found in the dry lakebeds of California’s Mojave Desert and Africa’s Sahara, but would likely be lost during the fall of meteorites.
In an editorial about the findings, Yasuhito Sekine from the Institute of Science Tokyo, who was not involved in the research, expressed that the analysis of samples obtained directly from the asteroid and meticulously preserved on Earth was essential for this discovery.
McCoy pointed out that the combination of life’s ingredients with environments enriched with sodium-rich saltwater or brines constitutes a potential “pathway to life.” He speculated that these processes likely occurred more extensively and at earlier stages than previously recognized.
Daniel Glavin of NASA noted that one of the most surprising findings was the relatively high nitrogen content, including ammonia, within the samples. Although all organic molecules found in the Bennu samples had previously been identified in other meteorites, Glavin emphasized that these were genuine extraterrestrial organic materials formed in space, not influenced by earthbound contamination.
Bennu itself, a collection of rubble measuring only a third of a mile (half a kilometer) in diameter, originated from a much larger asteroid that was fragmented by collisions with other space debris. Current findings imply that its parent body may have housed extensive subsurface lakes or oceans, which evaporated over time, leaving behind this salty residue.
As part of ongoing initial studies, over sixty laboratories worldwide are analyzing fragments of Bennu, according to Dante Lauretta, the mission’s chief scientist from the University of Arizona.
The majority of materials collected during this $1 billion mission will be reserved for future research efforts. Scientists indicate that further testing is crucial to deepen our understanding of the Bennu samples and highlight the importance of continued asteroid and comet sample retrieval missions. China is set to launch its own asteroid sample return mission this year, while many are advocating for missions targeting rocks and soil from the water-rich dwarf planet Ceres, as well as for explorations of Jupiter’s moon Europa and Saturn’s moon Enceladus. Meanwhile, NASA has core samples prepared for transport from Mars, though the delivery process is currently on hold as the agency seeks the most efficient and cost-effective method for retrieval.
“Are we alone?” McCoy posed, indicating that one of the central questions driving this research remains the quest for understanding life’s existence beyond Earth.
