锆石晶与十美分硬币的大小比较 (IMAGE) Proceedings of the National Academy of Sciences Caption 锆石晶与十美分硬币的大小比较。分析和测量锆石晶中的磁铁矿晶体的磁化程度难度巨大;这类分析揭示了了冥古宙时期的地球磁场。 Credit Image courtesy of Julie Mansy (photographer), Rory D. Cottrell (University of Rochester, Rochester, NY), and John A. Tarduno (University of Rochester, Rochester, NY). Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.