Ryugu Sample Analyses Show Asteroids May Have Delivered Compounds Needed to Start Life on Earth

By Bob Yirka, Phys.org

An international team of researchers with a wide range of backgrounds has found evidence that asteroids provided the compounds necessary for life to get its start on Earth. In their paper published in the journal Nature Astronomy, the group describes their study of a small sample of material collected from Ryugu that was brought back to Earth.

Background on the Hayabusa2 Mission

In 2014, the Japanese space agency JAXA launched a rocket holding a space probe called Hayabusa2 that was sent to Ryugu—a C-type asteroid that has roughly the same orbit around the sun as the Earth. Once it reached its target, the probe collected surface samples and also dust collision samples, both of which were returned to Earth in 2020.

Since that time, the samples collected by the probe have been studied by a host of teams looking to learn different details about the asteroid and its history. In this new study, the research team examined a collision sample from Ryugu looking for evidence of asteroids as the source of many of the compounds needed for life on Earth.

Research Methodology

The work by the researchers involved placing grains of Ryugu material in a sealed chamber designed and built by the group, allowing for the use of a spectral microscope in a vacuum-sealed environment. The samples were placed on sapphire dishes to enable them to be studied using wavelengths beyond the visible spectrum. The dishes were placed on polished gold-coated mirrors to prevent contamination.

Using X-ray spectrometry and other inspection tools, the researchers found examples of hydrated magnesium, ammonium, and phosphorus. These findings demonstrate that asteroids like Ryugu are composed not only of organic elements and compounds, but also of compounds that are in their hydrated form, which could have served as building blocks for life on Earth.

Significance of Findings

The research team noted that the grains they analyzed originated in deep space, specifically from beyond Jupiter. If these grains had been formed any closer to the sun, they would have evaporated. Furthermore, the discovery of ammonium is particularly critical, as its molecule can release both hydrogen and nitrogen during decomposition, providing vital elements for life.

Comparative Analysis of Ryugu Samples

Implications for Astrobiology

The findings offer significant insight into the origins of life on Earth and broaden our understanding of astrobiology. This research could bolster the argument that the building blocks of life were delivered to early Earth via asteroids, enhancing the theory of panspermia, which posits that life may exist throughout the universe and be distributed by space dust, meteoroids, comets, and asteroids.

In summary, the study of Ryugu samples suggests that asteroids may have played a key role in providing the essential compounds necessary for the emergence of life on our planet. This insight not only opens new avenues for scientific inquiry into the origins of life on Earth but also positions asteroids as critical objects of interest in the search for life elsewhere in the universe.

Future Research Directions

The research team expressed hope that their findings would encourage further studies on asteroids and their potential contributions to the origins of life on planets, particularly Earth-like exoplanets.

References

• 1. C. Pilorget et al, Phosphorus-rich grains in Ryugu samples with major biochemical potential, Nature Astronomy (2024). DOI: 10.1038/s41550-024-02366-w
• 2. Nature Astronomy, link
• 3. Further exploration into the Hayabusa2 mission and its implications.

For More Information

To read further on this topic, see these articles:

• Preserved presolar silicate grains found in Ryugu samples
• Two teams report on study of Hayabusa2 asteroid samples