Mars Glacier Image (IMAGE) Colgate University Caption This image of a glacier on Mars shows the abundance of boulders within the ice. High-resolution imaging of the surface of Mars suggests that debris-covered glacier deposits formed during multiple punctuated episodes of ice accumulation over long timescales. Debris-covered glacial landforms called lobate debris aprons (LDA) are widespread on Mars. It has not been clear whether these LDAs formed over the past 300-800 million years during a single long deposition period or during multiple short-lived episodes of ice accumulation. To address this question, Joseph Levy and colleagues used high-resolution imaging to map boulders along 45 LDAs on the surface of Mars. The boulders are commonly clustered into bands across all LDAs, similar to boulders on ancient terrestrial debris-covered glaciers. The findings point to multiple cycles of ice accumulation and advance over the past 300-800 million years, extending evidence for climate change on Mars beyond the 20-million-year window provided by numerical modeling. Credit Joe Levy/Colgate University 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.