Figure 1 (IMAGE) Tohoku University Caption Diagram of the atmospheric evolution of Earth's ancient atmosphere estimated by this study. Credit ©Yoshida et al. Usage Restrictions Reporters may use freely these materials in news coverage with appropriate credit information. License Original 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.