2023届高考英语二轮复习外刊阅读模拟强化训练阅读理解专题七

高考英语外刊阅读模拟强化训练 阅读理解专题七 A The Atacama Desert in Chile is just about the driest place on Earth. In spots, it looks a lot like Mars. But it’s not lifeless, even in the hyper-arid regions. Using state-of-the-art equipment to probe the desert rocks, researchers found bits of DNA from an intriguing mix of microbes. Strikingly, 9 percent of the genetic fragments belong to organisms unknown to science, making them part of the “dark microbiome.” These organisms are bacteria that are “so strange and different,” as the report puts it, that researchers could not identify any known relatives. The Atacama is the Mars analogy and scientists believe it is a brilliant test bed for the search for Martian life. The research seems to bolster the long-term Mars exploration strategy of NASA and its partner, the European Space Agency. They are in the midst of a multistage mission called Mars Sample Return. If all goes as planned, samples of Martian soil obtained by NASA’s Perseverance rover will be hauled back to Earth. But this new research also highlights the challenges facing scientists who want to know the biological history of Mars. Microbial life, especially if extinct and long fossilized, may exist at or beyond the farthest limit of what can be detected with the kind of instruments small enough to be blasted into space and landed on another planet. The Perseverance rover continues to explore Jezero Crater, digging up and storing samples of Martian soil. The plan is to put another spacecraft on the surface, which would double as a launchpad. Perseverance would then deliver the samples to the lander, which would hurtle the material into orbit. The new research suggests this may be the most effective — and possibly the only conclusive —way to find out if anything was ever alive on Mars.“We know there are things to detect,” Azua-Bustos, a leading researcher said. “But if your instrument is not designed to be able to detect those things, then we have a problem.” 【题源 The Washingto