Figure. 3 (IMAGE) Tokyo Institute of Technology Caption Schematic images of early (4 billion years ago) and present Mars. The ancient N-bearing organics were trapped and preserved in the carbonates over a long period of time. Credit Koike et al. (2020) Nature Communications Usage Restrictions The image may only be used with appropriate caption and credit. 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.