The geologic shape of Mars’ ancient shorelines and its immediate inland areas indicates that two large meteorites—striking the planet millions of years apart—triggered a pair of mega-tsunamis. The resulting waves, which moved several hundreds of miles inland, reshaped the Martian landscape, leaving surface features that are still visible today. The two meteor impacts produced craters about 19 miles (30 km) wide, and would have generated tsunami waves that reached 400 feet (120 meters) high. By comparison, the tsunami that struck Japan in 2011 reached a maximum height of 128 feet (39 meters).
Traces of Ancient Mega-Tsunamis Discovered on Mars
