Core Insights - The analysis of rock samples from the "Ryugu" asteroid reveals that water existed in ice form on its parent body for over 1 billion years, providing significant clues for understanding the chemical composition changes of carbonaceous asteroids, their orbital evolution, and the origin of water on Earth [1][2] Group 1: Research Findings - The research indicates that carbonaceous asteroids may have contributed water to Earth not only in the form of hydrated minerals but also as ice, with the total water content potentially reaching 20% to 30% of the asteroid's mass, which is 2 to 3 times higher than previously estimated [2] - The study utilized isotopes of lutetium and hafnium to investigate the fate of water on carbonaceous asteroids, concluding that ice existed for over 1 billion years before melting during impact events [1][2] Group 2: Implications for Earth Science - The findings support the hypothesis that primordial carbonaceous asteroids, formed about 4.56 billion years ago in the outer solar system, later migrated inward, delivering water and carbon to Earth [1] - The research published in the latest issue of the journal Nature emphasizes the importance of further studies to address remaining questions regarding the presence and disappearance of water on carbonaceous asteroids [3]

Group 1 - The research team led by Hokkaido University has successfully determined the formation time of the materials constituting the asteroid "Ryugu," which is approximately 4.5673 billion years ago, shortly after the birth of the solar system [1][2] - The study indicates that the original solid materials of celestial bodies provide crucial insights into their origins, with previous analyses showing that the minerals from "Ryugu" were formed around 4.562 billion years ago from low-temperature aqueous solutions [1] - The research utilized scanning electron microscopy to analyze "Ryugu" samples, revealing the presence of calcium-aluminum inclusions formed in high-temperature regions exceeding 1000 degrees Celsius in the early solar system [2] Group 2 - The study found that the sizes of calcium-aluminum inclusions in "Ryugu" rock samples are generally below 0.1 millimeters, while those in other carbonaceous chondrites are relatively larger, suggesting a connection to the transport processes of early solar system solid materials [2] - This discovery provides valuable data for understanding the origins of the solar system and planet formation, potentially advancing related research [2]