Lava tubes down the side of Pavonis Mons. Image credit: ESA. Click to enlarge This photograph shows one of Mars’ three great shield volcanos: Pavonis Mons. The image was taken by ESA’s Mars Express spacecraft, and shows a top view of the extinct volcano as it rises 12 km (7.5 miles) above the surrounding plains. … Continue reading "Lava Tubes on Pavonis Mons"