Mars feature debated for being impact crater or supervolcano
A 75-km-wide landscape on Mars has led to speculations of it being a crater formed by a meteorite impact or a supervolcano. The image was captured by European Space Agency's Mars Express, which is exploring the Red Planet since 2003. Mars is known to host the largest volcano ever discovered in the Solar System, Olympus Mons, having a 25-km height.