Scientists have found evidence of microbial life in samples from the asteroid Ryugu that should have remained intact after being delivered from space. This emphasizes the difficulty of avoiding terrestrial contamination even under strict storage conditions.
Japan’s Hayabusa-2 mission delivered asteroid samples collected from nearly 200 million kilometers from Earth in 2019. The spacecraft managed to collect about 5.4 grams of material from the asteroid’s surface. The samples landed in South Australia before being transported to a laboratory in Japan — where the collected material was scrutinized in a vacuum and under a constant nitrogen stream to prevent contact with the Earth’s environment. The samples were then given to researchers around the world to analyze.
However, a team of scientists from Imperial College London, when analyzing the samples, found filamentous organic structures that they identified as terrestrial microorganisms. The scientists concluded that the contamination occurred after the capsule was delivered. This raises concerns about the efficacy of existing sterility protocols.
By comparison, NASA’s OSIRIS-REx spacecraft, which collected samples from asteroid Bennu in 2020, delivered them to Earth in 2023. Analysis of this debris has not found any traces of terrestrial bacteria so far, indicating a better sealing of the capsule with valuable material.
Ryugu belongs to the carbonaceous asteroids, the oldest objects in the Solar System. The exploration of such bodies allows us to study the chemical conditions that existed during the formation of the Solar System and the possible connection to the origin of life on Earth. Previously, organic molecules have been found on Ryugu that could be the “building blocks” of life brought to our planet by meteorites.
Despite significant advances in technology, sample return missions demonstrate how difficult it is to protect space material from terrestrial impacts. This remains a key challenge for future scientific expeditions.
Earlier we told you about how asteroids may have helped the origin of life on Earth.
Provided by Gizmodo
