Geology of Mars time. This section introduces several of the larger physiographic regions of Mars. Together, these regions illustrate how geologic processes involving volcanism, tectonism, water, ice, and impacts have shaped the planet on a global scale. The northern and southern hemispheres of Mars are strikingly different from each other in topography and physiography. This dichotomy is a fundamental global geologic feature of the planet. Simply stated, the northern part of the planet is an enormous topographic depression. About one-third of the planet’s surface (mostly in the northern hemisphere) lies 3–6 km lower in elevation than the southern two-thirds. This is a first-order
Mars hoax about twice as far away for the same apparent size. It has nine times the mass of the Moon, and would have about the same tidal effect (nine times the larger mass divided by relative distance cubed). The hoax has resurfaced a number of times since 2003, often showing an altered image of twin moons over the Nilov Monastery, and may continue to do so, always announcing an imminent close Earth–Mars approach. The content of the original email, although almost entirely correct for August 27, 2003, has falsely been redated to announce a new close Earth–Mars approach—the real close approach