PART I

NATURAL FEATURES

CHAPTER

I. ON EXPLORATION 3

II. A DEPARTURE-POINT 12

III. A BIRD’S-EYE VIEW OF PAST MARTIAN DISCOVERY 20

IV. THE POLAR CAPS 32

V. BEHAVIOR OF THE POLAR CAPS 41

VI. MARTIAN POLAR EXPEDITIONS 54

VII. WHITE SPOTS 73

VIII. CLIMATE AND WEATHER 82

IX. MOUNTAINS AND CLOUD 96

X. THE BLUE-GREEN AREAS 108

XI. VEGETATION 119

XII. TERRAQUEOUSNESS AND TERRESTRIALITY 128

XIII. THE REDDISH-OCHRE TRACTS 148

XIV. SUMMARY 159