NASA’s OSIRIS-REx mission has delivered groundbreaking insights about the origins of life, thanks to pristine samples collected from the asteroid Bennu. The findings, published recently, reveal Bennu contains the building blocks of life, including amino acids and nucleobases—key components of proteins and DNA. This suggests the conditions necessary for life may have been widespread across the early solar system, raising tantalizing questions about the potential for life beyond Earth.
Returning approximately 120 grams of material—around the weight of a banana—OSIRIS-REx marks the first time the U.S. has conducted such an analysis of extraterrestrial samples. Initial studies had confirmed high-carbon content and the presence of water. Still, the latest research has extended our knowledge even more.
Scientists discovered Bennu’s parent asteroid once harbored liquid water, which evaporated and left behind what’s been described as a “briny broth” of salts and minerals. Some of these compounds had never been observed in space samples before. “These are the raw ingredients of life,” stated Tim McCoy, curator of meteorites at the Smithsonian National Museum of Natural History and co-lead author of one of the studies.
Notably, the samples contained 14 of 20 amino acids used to create proteins on Earth, alongside ammonia and formaldehyde—chemicals necessary for amino acid formation. This finding suggests complex organic molecules could form naturally within the early solar system. “This is rewriting everything we know,” remarked Nicky Fox, head of NASA’s Science Mission Directorate, underscoring the potential ramifications of this discovery.
The pristine nature of the Bennu samples is particularly relevant. Daniel Glavin of NASA emphasized, “The clues we’re finding are incredibly fragile and could never survive Earth’s contamination.” This ensures the organic molecules detected are extraterrestrial, free from Earthly contaminants.
Delving to Bennu’s history as a “water world,” minerals such as calcite, halite, and sylvite indicate liquid water’s presence during its formation about 4.5 billion years ago. McCoy elaborated on this history noting, “These processes probably occurred much earlier and were much more widespread than we had thought before.” These discoveries fuel speculation about the origins of life within our solar system and beyond.
Could icy bodies like Europa or Enceladus, or even the dwarf planet Ceres, host similar environments conducive to life? “Even though asteroid Bennu has no life, the question is could other icy bodies harbor life?” mused Nick Timms from Curtin University. The findings do not confirm extraterrestrial life, but they do present compelling evidence for the ingredients necessary for life being prevalent beyond Earth.
Sara Russell, a cosmic mineralogist at the Smithsonian, expressed optimism about the new research, noting it makes “huge progress” in how asteroids like Bennu evolved and their role during Earth’s formative years. These revelations scratch the surface of our comprehension of life’s origins and open doors to countless future investigations.
The excitement surrounding Bennu's discoveries extends its relevance beyond mere academic interest—it touches on the very essence of human curiosity: are we alone? The tantalizing evidence delivered by OSIRIS-REx suggests answers may lie within the stars.
Still, much remains unclear about the conditions required for life to emerge. While we now know we have the basic building blocks for life from Bennu’s samples, McCoy cautioned, “We don’t know how far along the pathway this environment could allow things to progress.” The quest for knowledge continues.
NASA’s findings from Bennu are also timely, considering the increasing emphasis on astrobiology and the exploration of the cosmos. The presence of key materials strengthens arguments for future missions targeting various celestial bodies. Discoveries from asteroids like Ryugu align similarly with Bennu’s insights, emphasizing the importance of investigating these remnants of the early solar system.
With careful study, scientists hope to identify whether asteroids played pivotal roles on Earth’s development and the origins of life within our solar system, igniting new discussions about our place among the stars. The analysis of Bennu is not just lighting the path forward; it’s rewriting the story we thought we knew about the beginnings of life on Earth.