Daniel Finn-Foley (03/10/04)
Carr's article about the history and features of Mars was very informative. He began with a discussion on the history of the exploration of Mars, touching on each of the missions designed to retrieve data from Mars including the Mariner and Viking missions. As our knowledge of Mars changed, so did our perception of it. In the early 20 th century Mars was thought to have had a thriving civilization on it, as evidenced by what many people believed to be canals designed to bring water from the poles to groups of Martians in the more equatorial regions. These beliefs were put to rest when the Mariner missions took a series of pictures of the highlands of Mars, revealing a cratered and desolate landscape more akin to our moon then Earth.
Later missions revealed that Mars is a dichotomy of geological features. While the highlands revealed a cratered wasteland, the lowlands revealed when Mariner 9 was sent into orbit of mars showed a much more plain Earth-like area with fewer craters. As more information was obtained Mars seemed more and more like earth. Despite being about half the radius of the Earth, Mars retains a thin atmosphere, and while too cool for liquid water to exist, frozen water is readily visible at the poles. Other features stand out on Mars, such as the vast volcanoes whose mere nine kilometer high base escarpments dwarf many terrestrial volcanoes, with calderas as high as 26 km. Their size may be related to Mars' lack of plate tectonics, one of the features that sets earth apart from it's distant cousin. Other features, such as canyons which may have been formed by the movement of water, indicate a past for Mars that may have been rich in liquid water, a stunning contrast to the desolate planet that met our Martian landers.
The idea of liquid water on Mars ties in with Soffen's article about life in our solar system. By today's standards life would be impossible on Mars. Most organisms on Earth require an atmosphere, light, and most importantly, liquid water. Theories that all life would require oxygen of some sort were put to rest by new evidence that the primordial Earth did not have an atmosphere as rich with oxygen as the one we know today. Instead, scientists theorized, life originated in the oceans of earth and seeded the atmosphere with oxygen, enabling life to evolve further in the future. Weather life used the energy of the sun or the core heat of the Earth itself emanating from deep sea vents, the prime ingredient is water.
Although early experiments on Mars revealed no sign of life, hopes remain high that life could be discovered there. All the signs point to Mars being a water rich world in the past, the perfect stage for life to take hold and prosper. The question of whether life did appear on Mars is one that is still being debated, and holds the key to humanity's seemingly lonely place among the stars.