240903-Hirata-Ganymede-Topography (IMAGE) Kobe University Caption Distribution of furrows and the location of the center of the furrow system shown in the hemisphere that always faces away from Jupiter (top) and the cylindrical projection map of Ganymede (bottom). The gray regions represent geologically young terrain without furrows. Furrows (green lines) exist only on geologically old terrains (black regions). Credit HIRATA Naoyuki Usage Restrictions Credit must be given to the creator. License CC BY 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.