CAPE CANAVERAL, Fla. — NASA's groundbreaking OSIRIS-REx mission, which brought back samples from the near-Earth asteroid Bennu, has revealed astonishing insights about the building blocks of life. Scientists announced on January 29, 2023, the significant findings from the analysis of these samples, marking the return of 122 grams of dust and pebbles, which may hold the key to answering the age-old question: Are we alone?
The extracted samples contain important organic material, including amino acids—the fundamental building blocks of proteins—as well as signs of ancient water, including clays and brines. Tim McCoy, from the Smithsonian Institution and lead author of one of the studies, articulated the potential of these findings, noting, “That’s the kind of environment could have been... steps lead from elements to life.” This environment appears to have coexisted with the components necessary for life nearly 4.5 billion years ago, pointing to how asteroids like Bennu could be instrumental in delivering life’s ingredients to Earth.
The two studies published in the journals Nature and Nature Astronomy detail the wealth of information garnered from Bennu's samples. Among the 14 biological amino acids found, each is integral to life as we know it, though none counts as life itself. The presence of ammonia and other nitrogen compounds suggests complex chemical processes took place on Bennu, perhaps even before Earth was formed. "Asteroids provide a time capsule... ingredients existed before life started on Earth," said Nicky Fox, associate administrator of NASA’s Science Mission Directorate.
Asteroids are regarded as pristine relics from our solar system’s formation, untouched by the various geological and atmospheric processes occurring on larger celestial bodies like planets and moons. Therefore, they act as natural time capsules, offering scientists unparalleled insights. According to Jason Dworkin, OSIRIS-REx project scientist, "The majority of the Bennu sample is still unexplored... for decades to come," indicating the room for future discoveries as analysis continues.
The process of collecting and studying these samples was fraught with challenges, particularly concerning contamination. To maintain the integrity of the samples, rigorous procedures were followed. The samples from Bennu were managed without exposure to Earth's atmosphere, pumped full of nitrogen gas. Explaining the importance of these measures, Danny Glavin, also involved in the study, remarked, "The clues we’re looking for... from exposure to Earth’s environment." Collectively, this careful curation allows researchers to piece together the historical narratives of our solar system.
One intriguing aspect of the findings involves the handedness of the molecules present. Life on Earth selectively utilizes left-handed amino acids, posing intriguing questions about the origin of this preference. Surprisingly, the samples from Bennu exhibited equal amounts of left- and right-handed molecules. This raises questions about how this preference could have arisen, reinforcing the enigma behind life’s mysterious occurrences. “Why we... see life on Earth and not elsewhere—that’s the truly tantalizing question,” reflected Jason Dworkin.
The $1 billion OSIRIS-REx mission is part of NASA’s broader efforts to understand our place in the universe. And as scientists continue analyzing the Bennu samples, discussions about future missions are underway. Countries like China are set to launch their own asteroid sample-return missions, paving the way for broader cosmic explorations. With intentions focused not only on asteroids but potential ocean worlds such as Jupiter's moon Europa and Saturn's moon Enceladus, the quest for knowledge about extraterrestrial life remains fervent.
While delivering riveting revelations, the latest findings from Bennu inevitably push scientists to contemplate the future. The persistent query—Are we alone?—now carries even more weight as researchers examine the possibility of life's origins being tied to materials from celestial bodies like Bennu. The intersection of these findings with humanity’s quest for answers about life beyond Earth is many researchers’ ultimate hope. The mysteries of life might just be written among the stars, waiting to be uncovered.