Researchers analyzing pristine material from the asteroid Bennu, returned by NASA’s OSIRIS-REx mission, have identified ribose and glucose, two bio-essential sugars. According to a study in Nature Geoscience led by Yoshihiro Furukawa of Tohoku University, these findings, combined with previous detections of nucleobases and phosphate, mean that all the chemical components needed to form RNA were present in Bennu material. The discovery suggests these molecules were available for incorporation into early planetary systems before life emerged on Earth.
The Chemical Inventory of Asteroid Bennu
The OSIRIS-REx mission, which delivered samples from Bennu to Earth in September 2023, has provided a rare, uncontaminated look at solar system chemistry. Unlike meteorites that risk terrestrial contamination during atmospheric entry and recovery, the Bennu sample was curated under controlled conditions. This precision allowed Furukawa’s team to use gas chromatography and mass spectrometry to detect trace amounts of sugars, including ribose, glucose, lyxose, xylose, arabinose, and galactose.
While the concentrations remain tiny—ribose at 0.097 nanomoles per gram and glucose at 0.35 nanomoles per gram—their presence is significant. These sugars represent the missing pieces of a puzzle that began with the 2025 Nature Astronomy report from Daniel Glavin’s team, which identified all five DNA and RNA nucleobases, along with ammonia and amino acids, within the same samples.
Did you know?
The absence of deoxyribose—the sugar used in DNA—in the Bennu sample analysed supports the “RNA world” hypothesis. This theory proposes that RNA came before DNA and proteins as the first major informational and catalytic molecule.
Aqueous Alteration and Prebiotic Synthesis
The presence of these sugars is not random. The Nature Geoscience paper argues that the sugar distribution aligns with products from formaldehyde chemistry. Researchers suggest that Bennu’s parent body likely underwent long-term alteration by aqueous fluids, where water-bearing, salty brines facilitated the synthesis of these organic compounds.
This geochemical history matches previous findings of an evaporite sequence on Bennu, which serve as mineral evidence that the asteroid’s parent body once contained salty fluids. By studying these minerals, scientists can reconstruct the chemical landscape that existed long before Earth’s oceans became the stage for biological evolution.
Beyond the “RNA World” Hypothesis
While these findings highlight the availability of raw materials, they do not prove that life originated on Bennu or that RNA was assembled there. As researchers emphasize, having the ingredients for bread—flour, water, and yeast—does not equate to having a loaf of bread. The transition from prebiotic chemistry to biology requires mechanisms to concentrate, activate, and polymerize these molecules.
The current data provides a “chemical inventory” rather than a biological blueprint. By identifying that these components share a common setting, researchers can now shift their focus toward the next phase of the origin-of-life puzzle: understanding the environmental selection and concentration processes that eventually allowed these extraterrestrial ingredients to function in a biological system.
Pro Tip:
Follow the official NASA OSIRIS-REx mission page for ongoing updates regarding the analysis of the Bennu sample. The agency continues to release peer-reviewed data as the curation process reveals more about the asteroid’s complex organic composition.
Frequently Asked Questions
Did scientists find life on the asteroid Bennu?
No. Scientists found the chemical building blocks of RNA, such as ribose and nucleobases. These are non-living molecules that are essential for life as we know it, but their presence does not indicate the existence of life on the asteroid.
Why is the Bennu sample better than a meteorite?
According to NASA, the Bennu sample is superior because it was collected directly from a known asteroid and handled in a controlled environment. Meteorites are exposed to Earth’s atmosphere and surface conditions, which can introduce terrestrial contamination and degrade organic compounds.
What is the significance of finding ribose?
Ribose forms the sugar in RNA’s sugar-phosphate backbone. Its presence, alongside previously discovered nucleobases and phosphate, confirms that the three primary components needed to form RNA were present in the early solar system, independent of Earth-based biological processes.
Are you interested in the latest updates on space exploration and astrobiology? Subscribe to our newsletter to receive the latest research findings directly in your inbox.
Worth a look
