Scientists have confirmed the discovery of essential ingredients for life in samples collected from the asteroid Bennu. This finding supports the theory that asteroids may have delivered critical components necessary for the emergence of life on Earth and potentially elsewhere in the solar system. The pristine fragments were brought to Earth by NASA’s OSIRIS-REx mission, which returned the samples in 2023.
The recent analysis revealed several sugars fundamental to biological processes, including ribose, a vital building block of RNA. This discovery completes the inventory of key life-forming compounds found in the asteroid material. Earlier studies had already identified water, carbon, amino acids, and phosphates in the Bennu samples. Furthermore, all five nucleobases that compose DNA and RNA were detected. Yet, the critical sugar component necessary for forming the backbone of these genetic molecules was absent until now.
Groundbreaking Findings from Asteroid Research
Lead researcher Yoshihiro Furukawa from Tohoku University stated, “These sugars complete the inventory of ingredients crucial to life.” He emphasized that this research shows that asteroids “really could have delivered all the ingredients necessary for life to Earth or to other bodies in the solar system, like Mars.” The team analyzed a small portion of the samples and found not only ribose but also other sugars such as glucose, which is essential for the metabolism of nearly all life forms on Earth.
The prevailing scientific theory posits that these sugars originated from chemical reactions in briny water on Bennu’s larger parent asteroid over 4.5 billion years ago. The OSIRIS-REx spacecraft collected these samples in space and sealed them, ensuring that they remained uncontaminated by Earth’s environment. This unique condition has allowed scientists to undertake an unprecedented study of pristine extraterrestrial chemistry. While similar compounds have previously been detected in meteorites that have landed on Earth, concerns about contamination have always lingered.
“This finding in the Bennu sample guarantees that these results were true,” remarked Furukawa, whose team’s findings were published on October 3, 2023, in the journal Nature Geoscience.
Implications for the Search for Life
The discovery carries significant implications for our understanding of the origin of life. The presence of ribose, without the accompanying sugar 2-deoxyribose (found in DNA), lends strong support to the “RNA world” hypothesis. This theory suggests that the earliest life forms on Earth were based on RNA, capable of storing genetic information and replicating, with DNA evolving later.
Astrobiologist Danny Glavin at NASA’s Goddard Space Flight Center, who is also a co-investigator on the OSIRIS-REx mission, expressed optimism about the findings. He explained that if these materials were widespread throughout the early solar system, it is possible that locations such as Mars or Jupiter’s icy moon Europa might also have been enriched with the raw ingredients for life. “I’m becoming much more optimistic that we may be able to find life beyond Earth, even in our own solar system,” Glavin stated in a NASA video announcing the findings.
The ongoing analysis of the Bennu samples will likely continue to inform our understanding of life’s potential origins and the processes that may have led to its emergence across the cosmos.
