WATERAND、LIFE、ON MARS
1The presence or absence of water has a direct bearing on the possibility of life on other planets. In the nineteenth century, it was commonly accepted that life, perhaps even intelligent life, was widespread in the solar system, and Mars was an obvious target in the search for life. New photographic technology offered a way for astronomers to learn more about the red planet. In 1888, Italian astronomer Giovanni Schiaparelli produced images that showed a network of long, thin, dark lines crossing the surface of Mars. He called these features canali in Italian, which became "canals" or "channels" inEnglish. The strange appearance of the canals suggested to some scientists that they had been formed artificially rather than naturally. The mystery deepened when Schiaparelli observed that many of the canals in the photographs were actually double.
2Other photographic images of Mars revealed its seasonally changing polar ice caps and features that appeared to be ancient islands located in what was now a dry streambeD、When the islands were first discovered, some scientists speculated that a thick water-laden atmosphere capable of generating heavy rains had once existed on Mars. However, others remained unconvinced of the presence of water. Then, in 1963, a team of astronomers obtained a good photographic plate of the near-infrared spectrum of Mars. The photograph showed that, faintly but definitely, water vapor lines could be seen. This photograph established that there really was water on Mars, though the amount was very small. Today, the presence of water vapor in the Martian atmosphere is generally accepted, as is the belief that the atmosphere was once much denser than it is now, with a much greater abundance of water vapor.
3The surface of Mars is dry today, but it does contain significant amounts of ice and signs that liquid water once flowed over the planet.All of the locations where evidence of water has been found are ancient, probably formed very early in Martian history.Data transmitted from spacecraft on Mars in 2004 have revealed that water was once common across a vast region of the planet, possibly as shallow lakes or seas that dried out and then filled up again. There are signs that the wind blew debris around during dry stages. These seas and lakes extended across hundreds of thousands of square miles, creating habitable conditions during long stretches of time billions of years ago.
4 Evidence of water includes the presence of various minerals known as evaporates, deposits left behind when liquid water turns to vapor. Small areas of mineral deposits have been found in Valles Marineris, a huge hole on Mars that is larger than the GrandCanyon onEarth. The minerals there contain water, so they had to be formed in the presence of water. Geologic research has also turned up clay and gypsum deposits that were formed by water in the soil. Rocks that clearly formed in water extend throughout 300 meters of layered materials in several locations across the Martian plains. The layers were built up over time, which means water was present, at least temporarily, for extended periods on ancient Mars.
5 Besides the ice packs at Mars’s poles, astronomers have discovered a frozen sea near its equator. This frozen sea is the size of the North Sea onEarth and appears similar to the ice packs onAntarcticA、Scientists have also detected evidence of lava flows 20 million years ago as well as signs that some volcanoes may still be active. Several recently formed volcanic cones near Mars’s North Pole indicate that the planet’s core may interact with the surface, meaning there was both warmth and moisture in the recent pas-circumstances that might have supported life.
6Liquid water is the key ingredient for life as we know it. Of all the other planets in the solar system, Mars is most likeEarth. The fact th

ConsumerDemand andDevelopment of GreenCars
The day automakers put the earth at the top of their agenda will go down in history. Reading this book, one gets the sense that day is coming, major automakers—still no paragons of environmentalism—have gotten the message that replacing the dirty internal-combustion engine is an urgent priority. With less than 5 percent of the world’s population,Americans produce 14 percent of all global warming carbon-dioxide gas.And car tailpipes pump out more than 30 percent of U. S. air pollution.
In his new book, ForwardDrive: The Race toBuild "Clean"Cars for the Future, environmentalist Jim Motavalli concludes that capitalist competition is leading the way over government mandates to clean up that exhaust. Motavalli chronicles the movement for cleaner cars: the few visionaries and zealots building and driving home-built battery-powered cars; the divided giant automakers working tirelessly to develop clean cars while fighting regulatory efforts to require them; university researchers concluding studies; and the regulators trying to speed their adoption.
ForwardDrive covers the technological advances of the hybrid and fuel-cell vehicles poised to take over from the internal-combustion engine. In some ways, Motavalli is an unlikely narrator.A、self-vowed car nut who stumbled into a job editingE, theEnviromental Magazine, he seems biased on both sides of the issue.But ultimately, that’s what makes him best suited to tell this story.
Motoavalli’s concern for the environment is sincere, and his knowledge of cars is refreshingly accurate. The most interesting passages follow his transformattion from internal-combustion devotee to environmental auto cynic and battery-car zealot to hopeful future-car realist. "It was disconcerting, to say the least, to learn that my hobby of collecting classic cars and my growing concern for the environment didn’t necessarily mesh," Motavalli writes. "The car has certainly been good to me, but I’m becomin disenchanted."
In the preface, he noted that he set out to write a book critical of the auto industry for teaming up with major oil companies to block the development of clean cars.But when he dug in to do more research, he found a different story. Namely that automakers inDetroit, Japan, andEurope are in a heated race to start selling cars that are more environmentally correct.
A、[■] Unfortunately, Motavalli glosses over issues of consumer deman
D、
B、[■] He never mentions that today’s electric cars and gasoline-electric hybrids cost far more than internal-combustion cars of equal or greater capability.
C、[■] He notes their utter dedication to their electric cars and implies that the rest of the buying public should simply be as enthusiastic, without addressing issues of price or various ways families use their cars.
D、[■]
He strongly favorsCalifornia’s mandate that 10 percent of all vehicles sold in the state be zero-emission-vehicle-battery or fuel-cell electrics, not hybrids—even though he writes, "Ultimately, vehicles halfheartedly designed to meet a mandate would fail in the marketplace."And he gives a short shift to the point that clean cars do nothing to ease congestion and sprawl.
In a telephone interview, Motavalli concedes that technology is progressing faster than the book deadline allowed him to keep up with. If anything, automakers are working harder to develop hybrid-electrics.And mass-market hybrid-drive systems will likely first show up in the big sport utility vehicles that Motavalli rails against.
Nevertheless, he now believes that the automakers with the deepest pockets have the best chance of building better cars for tomorrow. "The new, clean cars will emerge not from a tinkerer’s garage, but from the well-funded research labs of the same big auto companies t

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