Tyrrhena Terra

The 1000 x 2000 km area region of Tyrrhena Terra (outlined by the

white box in the inset) sits between two regions of low altitude – Hellas

Planitia and Isidis Planitia – in Mars’ southern hemisphere, as shown in this

global topography map. Hydrated minerals were found in 175 locations

associated with impact craters in Tyrrhena Terra, such as inside the walls of

craters, along crater rims, or in material excavated by the impact. Analysis

suggests that these minerals were formed in the presence of water that

persisted at depth for an extended period of time.