In tracing all of Mars’ history as seen from Earth, William Sheehan and Stephen James O’Meara undertake an ambitious project. Mars: The Lure of the Red Planet is a journey of mankind’s fascination with the fourth planet from the Sun. Sheehan and O’Meara take all humankind’s recorded accounts of Mars—some going back over ten thousand years—and highlight significant scientific discoveries and dramatic stories up to the present time. Even in this distillation of the high points in Mars’ history, the authors manage to cover a lot of ground.
The journey starts in 1997 with the landing of the Mars Pathfinder, the first vehicle to land on Mars in twenty-one years. The Mars Pathfinder was the closest humans had ever come to Mars, and its cameras showed Mars as it actually is: arid, barren, and with no signs of life at all. There is an ongoing debate about whether there was ever any life on Mars in the past, and Pathfinder did not give the answers very clearly, but it gave scientists their first clues in a long time. The Pathfinder also provided many exciting firsts, including views of the moon Deimos and of a live sunset from the surface of Mars itself. Even the landing of the Mars Explorer was an event that, to the scientists, rivaled the excitement of a ride at Walt Disney World.
The authors then take up their quest at the beginning of human history. Mars has always been up in the heavens waiting for humans to notice, and while there is no proof that humans looked at Mars some sixteen thousand years ago, it is assumed that they did. The Babylonian name for Mars was Nirgal, or the Star of Death, suggesting that the planet already had a negative association, even though, to the naked eye, it did not look different from any other star in the sky. Aristarchus of Samos (fl. c. 270 b.c.e.) suggested the movement of Mars was an illusion, and that not only was Mars not stationary, but everything around it—including Earth—was moving also. It was a radical idea for the time, and one that eventually turned out to be true.
Many early astronomers studied Mars, including Nicolaus Copernicus and Tycho Brahe, but in 1605, Johannes Kepler made the first true discovery about the red planet. The orbit of Mars was elliptical, but only by assuming that every other planet’s orbit was elliptical as well did Mars’ position in relation to Earth suddenly make sense. If Kepler had believed that Earth was the center of the universe and everything else followed around it in a circular pattern—as Tycho did—then he never would have been able to figure this out. By studying Mars first, Kepler made an important discovery, which he published in 1605 and which would later be called his First Law. Now astronomers had the key to figuring out the position of any planet at any time, something they still count on today. Kepler’s Laws did not just apply to Mars, but to the entire solar system. Kepler’s Third Law (or Harmonic Law), discovered in 1619, said that the distance from the Sun and the periods of the planets were intertwined. In other words, Kepler realized that any two objects orbiting each other—such as the Sun and Mars—would affect each other through gravity. This law gave Kepler the key to the scale of the solar system.
In 1877, Giovanni Schiaparelli decided to draw the first map of Mars in its entirety (there had been earlier attempts at mapping Mars’ markings). Percival Lowell, another great astronomer and a contemporary of Schiaparelli, said Mars was to Schiaparelli what America was to Christopher Columbus: an undiscovered country waiting to make its appearance known. Schiaparelli would also be famous for drawing what he called canali, or canals. Lowell also saw the canals and proposed a theory in 1894 that would forever affect the way Mars was viewed.
The sights Lowell saw through his telescope appeared to be paths that could not have been made by nature....
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