Chasma Boreale (IMAGE) University of Arizona Caption Chasma Boreale is a vast canyon cut into the icy cap that covers Mars' north pole. This image, taken with the Mars Odyssey spacecraft, reveals the layers of ice and dust deposited during climate cycles year after year, slowly building up the canyon walls. Credit NASA 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.