An analysis has revealed the presence of the chemical building blocks of life in the grainy dust of an asteroid identified as Bennu. Samples from this space rock, collected by a Nasa spacecraft and brought to Earth, contain a diverse range of minerals and thousands of organic compounds. Notably, these include amino acids, playing a crucial role in protein structure, and nucleobases, the essential elements of DNA.
While this discovery does not confirm past life on Bennu, it does support the theory that asteroids delivered crucial components to Earth during collisions billions of years ago. Scientists speculate that similar compounds could have been spread to other planets within our Solar System.
Prof Sara Russell, a cosmic mineralogist from the Natural History Museum in London, commented on the significance of these findings, highlighting the insight they provide into the origins of life and the curiosity surrounding its beginnings.
The research unveiling these findings has been documented in two papers appearing in the journal Nature. The endeavor to obtain samples from Bennu has been described as one of Nasa's most daring missions, resulting in the retrieval of around 120g of valuable material enclosed in black dust.
Analysis has shown that Bennu is rich in nitrogen and carbon compounds, including amino acids crucial to Earth's biological processes, as well as the DNA components adenine, guanine, cytosine, and thymine. The abundance of minerals and salts on the asteroid suggests the presence of water in its history, with the discovery of ammonia further supporting this notion.
The study has expanded our understanding of the role asteroids may have played in delivering water and organic material to Earth, essential for the emergence of life. Dr. Ashley King from the Natural History Museum emphasized the significance of this research, pointing out that asteroid impacts might have provided the necessary ingredients for life across the Solar System.
Further investigation will focus on the samples obtained from Bennu, driving continued exploration and discovery in our cosmic vicinity.