Scientists believe the ridges and troughs they discovered are the surviving remnants of beach deposits from the lake. A project lead by Research Associate Gaetano Di Achille with the help of Assistant Professor Brian Hynek and Research Associate Mindi Searls all of the University of Colorado at Boulder Laboratory for Atmospheric and Space Physics, discovered the shoreline while examining images taken by the High Resolution Imaging Science Experiment (HiRISE) on NASA’s Mars Reconnaissance Orbiter. HiRISE orbits about 200 miles above the planet but can resolve features as small as one meter in size on the surface.
Located in a large valley called the Shalbatana Vallis, the remnants of the lake deposited sediment that formed the delta observed in the photographs. The images also indicate that water carved a 30 mile long canyon opening into the valley. The observed geological features indicate a stable, long-lived lake in that location. The lack of additional shorelines indicates the lake likely dried up very quickly, possibly during a period of rapid climate change.
Interestingly, the lake has been placed in an era about 300 million years after the wet and warm Noachan epoch when the planet was bombarded by meteors and experienced extensive flooding. Instead, it formed during the Hesperian epoch, typically characterized by lava flows and the formation of volcanoes like Olympus Mons.
Scientists are particularly interested in exploring the deltas near the lake. On Earth such deltas are rich with organic carbon and other biomarkers. If a Mars with water and life was similar, these deltas represent a good opportunity to find signs of life on the planet. These deltas would be a prime landing target for a future Mars mission capable of soil analysis and other types of physical examination of the area. Researchers believe such a mission could lead to proof that life existed on Mars in the past.
TFOT has previously reported on the search for water or life on Mars including this report on the discovery of toxic chemicals on the planet and the Phoenix Mars Lander’s analysis of the planet’s icy soil showing its similarities to the soil of Antarctica. TFOT has also reported on geologic features of Mars including high resolution photographs taken of the Hebes Chasma by the Mars Express Orbiter, high resolution photographs taken of dust storms on Mars by the Hubble Space Telescope, and a video of Caltech scientists explaining the geologic history of Mars. TFOT has also covered Google Mars, an application that lets you explore Mars from your desktop computer.
Read more about the discovery of the Martian shorelines and its implications in this University of Colorado at Boulder press release.