The asteroid Bennu is turning out to be a remarkable time capsule, offering scientists rare clues about the origins of our solar system and the molecular seeds that may have helped spark life on Earth. As researchers continue analysing the pristine material brought home by NASA’s OSIRIS-REx mission, three new papers published in Nature Geoscience and Nature Astronomy have unveiled discoveries that are as surprising as they are profound: essential biological sugars, a strange gum-like substance never before seen in space rocks, and an unusually high concentration of dust forged in ancient supernova explosions.
One of the most striking findings comes from a team led by Yoshihiro Furukawa of Tohoku University, who detected two sugars critical to life as we know it. Among them is ribose, a five-carbon sugar that has long fascinated scientists because it forms the backbone of RNA. The team also found glucose, a six-carbon sugar and one of life’s most common energy sources. While neither discovery is evidence of life, their presence suggests that the raw ingredients needed to build biological molecules were far more widespread across the early solar system than once believed. Ribose has been detected in meteorites before, but the Bennu samples stand out because they contain no trace of deoxyribose, the sugar that forms DNA. This imbalance may indicate that ribose was more common on young planetary bodies, adding weight to the “RNA world” hypothesis, which proposes that early life relied on RNA to store information and catalyse reactions long before DNA and proteins evolved.
Another team, led by NASA’s Scott Sandford and UC Berkeley’s Zack Gainsforth, revealed something that startled even seasoned researchers: a bendable, translucent, polymer-like material that resembles used chewing gum. Embedded deep within Bennu’s grains, this “space gum” is unlike anything previously identified in astromaterials. It appears to have formed in the solar system’s infancy, when Bennu’s parent asteroid slowly warmed. During this period, molecules such as ammonia and carbon dioxide may have combined to form carbamate, a compound that later polymerised into more complex, water-resistant structures. These flexible, nitrogen- and oxygen-rich chains hint at chemical processes that could have produced precursors to life long before Earth itself held liquid water.
To examine the mysterious substance, scientists used an array of advanced tools, slicing micrometre-sized grains thinner than a human hair and analysing them with high-resolution electron microscopes and X-ray beams. What emerged was a picture of a material somewhat similar in its chemical groups to polyurethane, though far more chaotic in structure. Its very existence suggests that organic complexity arose even in the cold, early stages of asteroid formation, potentially spreading chemically rich seeds throughout the developing solar system.
A third study, led by Ann Nguyen of NASA’s Johnson Space Center, focused on presolar grains—tiny particles older than the Sun itself. These grains revealed that Bennu’s parent body incorporated an unusually high abundance of dust formed in supernova explosions, roughly six times more than any previously studied sample. Such an enrichment suggests the asteroid formed in a region of the solar nebula thick with the remnants of dying stars.
