Abigail Fraeman, Emily Lakdawalla, and Loren A. Roberts for The Planetary Society
Geologic Environments Encountered by Spirit and Opportunity on Mars
ABOVE Spirit and Opportunity explored 5 major geologic environments. THE LAVA FIELDS OF GUSEV CRATER, where Spirit landed, showed no evidence for water. THE COLUMBIA ILLS, much older than the Gusev plains, contained rocks altered by groundwater. HOME PLATE, an extinct volcano, had hot springs and fumaroles. MERIDIANI PLANUM contained sedimentary rocks laid down in water and later altered by groundwater. ENDEAVOUR CRATER RIM had fractures that acted as conduits for groundwater multiple times.