ancient

Space & Cosmos

Fossils in rocks frozen in time hint at ancient climate on Mars

An ancient giant ripple imaged by the High Resolution Imaging Science Experiment on Terra Sirenum, Mars, has consistent wavefront wavelengths, numerous cracks and craters, and may be partially covered by ancient lava flows. Courtesy of NASA/JPL/University of Arizona. Long ago, wind and water currents shaped Mars’ soft sands and sediments into dunes, ripples, and other landform patterns called bedforms. Over…