Mars Express takes a close look at the Mars volcano Tharsis Tholus

Mars Express takes a close look at one of Mars’ giant volcanoes, Tharsis Tholus.

At least two large sections have collapsed around its eastern and western flanks during its four-billion-year history and these catastrophes are now visible as scarps up to several kilometers high. The main feature of Tharsis Tholus is, however, the caldera in its center. It has an almost circular outline, about 32 x 34 km, and is ringed by faults that have allowed the caldera floor to subside by as much as 2.7 km.