With the Viking missions in the 1970s which included two orbiting probes and two landing craft areologists got more details of Martian topography.
ECONOMIST: Martian chronicles
2.
Global Surveyor, which has mapped the whole Martian surface, some of it down to a resolution of 1.5 metres, has shown that those areologists who kept the faith were right.
ECONOMIST: Martian chronicles
3.
Yet many areologists, as students of Mars are sometimes known, could not let go of the idea that the object of their affections was once an active world like the earth.