NASA Finds Mysterious Space Gum, Sugars & Stardust In Bennu Asteroid Autopsy

by Aaron Leong — Wednesday, December 03, 2025, 10:17 AM EDT

Samples retrieved from asteroid Bennu by NASA’s OSIRIS-REx mission in September 2023 have yielded a surprising treasure trove, revealing not just the building blocks of life, but also a mysterious "space gum" and ancient stellar dust.

Researchers have detailed three major findings published in Nature Geosciences and Nature Astronomy. Foremost among them was the detection of ribose, a sugar that serves as the molecular backbone of RNA, and glucose, the primary energy source for nearly all known life (which also marks the first time glucose has been identified in an extraterrestrial sample).

The discovery of ribose, coupled with the prior detection of all five nucleobases and phosphates in the same sample, means Bennu literally carries all the necessary components to form the RNA molecule. Yoshihiro Furukawa of Tohoku University, who led the sugar analysis, noted that the absence of deoxyribose (the sugar in DNA) supports the "RNA world" hypothesis, which suggests that early life relied solely on RNA to store genetic information and catalyze reactions before more complex DNA systems evolved.

nasa bennu sugars 092225 — A team of Japanese and US scientists have discovered the bio-essential sugars ribose and glucose in samples of asteroid Bennu (Click to enlarge; Credit: NASA/Goddard/University of Arizona/Dan Gallagher)

Adding to Bennu’s chemical story is the discovery of a polymer-like substance, swiftly dubbed "space gum." Researchers, including Zack Gainsforth and Scott Sandford, reported finding this unusual material which, though now hardened, was once soft and flexible, akin to plastic or used chewing gum. Space gum is extremely rich in nitrogen and oxygen, and scientists believe it formed in the long-lost parent body of Bennu when salty water and simple organic molecules reacted. What makes the material so important is that it appears to have formed before the parent asteroid warmed sufficiently to create a water-rich environment. The team noted that the gum's random, hodgepodge assembly of molecular chains could have been one of the very earliest chemical alterations preserved within the rock, perhaps acting as a precursor that may have helped kickstart terrestrial biology.

Furthermore, a third team found an unexpectedly high abundance of presolar grains, i.e. dust from stars that predated our Sun. Led by Ann Nguyen, the analysis revealed the sample contained six times more dust produced by ancient supernova explosions than any other astromaterial ever studied. This finding not only provides a unique chemical window into the ingredients that first accreted to form planets but also confirms that even a primitive object like Bennu holds pockets of material that escaped alteration, allowing scientists to look at events "near the beginning of the beginning," as astrophysicist Sandford puts it.