Fresh analysis of samples returned from the asteroid Bennu has revealed the presence of amino acids, ammonia, and various salts, bolstering the theory that the building blocks of life may have originated in space. The findings, stemming from NASA’s OSIRIS-REx mission, offer a deeper understanding of the chemical conditions present in the early solar system and how they might have contributed to the emergence of life on Earth.
The OSIRIS-REx probe successfully delivered samples from Bennu in 2023, and scientists have been meticulously studying the material ever since. Bennu, described as a “rubble-pile” asteroid rich in carbon, is believed to have formed approximately 4.5 billion years ago from a parent body potentially originating in the outer solar system – beyond Saturn. This parent body fragmented due to a collision.
Researchers identified 14 different amino acids commonly used by life on Earth within the samples, along with five nucleobases, essential components of DNA and RNA. These discoveries suggest that asteroids like Bennu could have delivered crucial chemical ingredients to early Earth, facilitating the development of life. This discovery underscores the potential role of asteroids in seeding planets with the necessary components for life.
Beyond organic molecules, the analysis revealed 11 distinct salts, including carbonates, phosphates, sulfates, and sodium chloride (table salt). The formation of these salts is linked to the evaporation of liquid water, mirroring conditions found in salt lakes on Earth. Similar saltwater environments have also been detected on other celestial bodies, such as the dwarf planet Ceres and Saturn’s moon Enceladus, highlighting the prevalence of liquid water throughout the solar system’s history.
NASA researchers emphasized that the Bennu samples are “pure” – meaning they haven’t been contaminated by Earth-based materials. This contrasts with previous analyses of organic matter found in meteorites that have fallen to Earth. “We are unveiling the mysteries of the solar system’s birth, and these samples provide us with a ‘time capsule’ to understand how life could have originated,” stated NASA Chief Scientist Nicky Fox, Ph.D.
The research has been published in the journals Nature Astronomy and Nature. More science and technology news can be found at 明日科學網.
