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]