ESA’s Mars Express Discovers Deep Valleys and Frozen Features Hinting at Mars’ Icy Past

In July 2025, the European Space Agency’s Mars Express orbiter captured a high-resolution image of Acheron Fossae, a region marked by deep chasms and ridges on Mars’s surface. These features, created by ancient crustal stretching, split the terrain into raised horsts and sunken grabens. Valley floors reveal smooth surfaces carved by slow-moving, ice-rich rock glaciers, forming rounded knobs and mesas. Scientists believe these structures date back 3.7 billion years, during Mars’s most geologically active era. The presence of rock glaciers hints at ancient ice ages, suggesting the Red Planet once had climatic cycles capable of supporting frozen water flow over vast periods, reshaping its landscape.