The analysis of minute asteroid fragments from Ryugu has provided significant insights into its past and chemical composition. These fragments were examined at the Advanced Photon Source (APS) using powerful X-ray beams, revealing crucial details about the asteroid's evolution.
Utilizing Mossbauer spectroscopy, scientists found that Ryugu initially consisted mainly of ice, which transformed as it traveled through space, experiencing temperature fluctuations over millions of years. The fragments contained elements that offered essential data about the conditions at the solar system's outer edges where they originated.
A key feature of the APS's contribution was its ability to focus X-ray beams down to 4 microns, allowing for detailed readings of fragments ranging from 400 microns to one millimeter in diameter. This precision enabled researchers to determine the oxidation state of iron in each sample, uncovering that Ryugu's structure was once porous and rich in ice. Over time, the ice melted, leaving behind a fine-grained, iron-rich residue, including pyrrhotite, an iron sulfide not found in meteorites similar to Ryugu fragments. This discovery provided new constraints on the temperature and location of Ryugu's parent asteroid during its formation.
Combined with findings from various research groups, APS data offered a comprehensive view of Ryugu's journey through space, illustrating its transformation from a large, icy body in the outer solar system to its current rocky form, rich in unique elements from its ancient origin.