The Quest for Mars: NASA scientists and Their Search for Life Beyond Earth. Laurence Bergreen. Читать онлайн. Newlib. NEWLIB.NET

Автор: Laurence Bergreen
Издательство: HarperCollins
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Жанр произведения: Прочая образовательная литература
Год издания: 0
isbn: 9780007440986
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called Nakhla that fell in Egypt in 1971,” he said. “The British Museum had a piece the size of a potato, covered with fusion crust, which protects it from contamination. The problem with the Allan Hills meteorite, ALH 84001, is that it may have been contaminated with carbon or terrestrial bacteria. A chunk of the Nakhla meteorite came in here, to our lab, and we had permission to break it up and pass it out to various investigators. We requested six grams. We think it’s likely to have the least contamination of any Martian meteorite.” I sensed he knew more, but this partial revelation was all he would risk revealing at the time.

      He also wanted me to know he hadn’t given up on ALH 84001 as the prime suspect in the search for life on Mars. He didn’t want me to think for one second that Nakhla was a substitute for ALH 84001; rather, it offered supporting evidence. As he talked, it became apparent that he felt that all the criticisms leveled at his findings, and there had been a lot of them, more than most scientists encounter in a lifetime, had only strengthened the arguments he originally advanced. To illustrate what he meant, he invited me to sit with him before a large monitor. “Here’s a new picture from the Allan Hills meteorite. We really suspect these are fossilized bacteria. They have better characteristics than what we have already seen; they are curved, segmented. If you gave this to a biologist, he’d say, ‘Of course it’s bacteria,’ but we have to prove beyond a shadow of a doubt it’s of Martian origin and fossilized. Fossilization is very common with bacteria; the organic components are replaced by mineral components such as iron oxide or silica. This can happen quickly, in a couple of weeks, and it happens when you bury the material in water. They are one hundred to two hundred nanometers long and forty to fifty nanometers wide, smaller than the big worms in the published pictures, which were five hundred nanometers long. My guess is that life is still on Mars, but it’s underground, in the water system. That’s where the underground organisms are living, a couple of kilometers underground. On Earth,” he reminded me, “there are microbes growing four kilometers underground.”

      As we parted, David McKay insisted, “Our critics have proved nothing. Our research has defeated each and every one of their arguments, and the case for ancient life on Mars is now stronger than ever.”

      Nine months after our meeting, McKay made his latest findings public at the 1999 Lunar and Planetary Science Conference in Houston; his announcement added to the controversy and ensured that the debate surrounding fossilized Martian bacteria would continue for years. To his way of thinking, there were now two meteorites from Mars bearing evidence of fossilized bacteria, ALH 84001 and the newcomer, from Nakhla, Egypt. His detractors claimed his analysis of the newer meteorite, Nakhla, compounded the errors he had made in his analysis of the first, but his supporters insisted it offered compelling confirmation of extraterrestrial life.

       3 GROUND TRUTH

      To reach the Jet Propulsion Laboratory, you take the freeway to Pasadena and get off at the Oak Grove Exit, then follow Oak Grove as it winds gently toward the mountains through the luxuriant landscape. You feel the smog settle on your chest as you go. There’s no suggestion of high technology in the area, just a somnolent Southern California suburb, lush, green, and slightly sullen. As you sense the end of the road approaching, you assess the looming mountains, but there’s still no sign of JPL, and you begin to wonder what gives. JPL isn’t exactly off-limits, but it’s not easily accessible, either. It will be found only by those who put some thought into looking for it. You think you’re finally there when several large white modern structures appear on the left, but as you drive up to them, you realize it’s a local high school, and then, just ahead, there’s a gate and a guardhouse, and that, at last, is JPL.

      People arrive for work early. By 7:30 AM, the parking lot is filled with Hondas and Fords and Nissans and Tauruses – nothing fancy, except the odd Corvette. Employees quietly fan out across the campus and go to work. The buildings at JPL are boxy, functional, crisp. Within its offices, there are the same horrible green plants you see everywhere at NASA, at headquarters or the Johnson Space Center in Houston. Once you’re indoors, you can forget all about Southern California; you might as well be in Washington or Florida; it’s NASA-land.

      Despite its innocuous location, JPL is among the world’s leading centers for spacecraft engineering and development. Started in 1936 as the Guggenheim Aeronautical Laboratory at the California Institute of Technology, JPL is now run jointly by NASA and Caltech. In the early days, there were just a few people on hand, including Frank Malina, a rocket enthusiast, and Theodore von Kármán, an influential Caltech professor. The lab barely survived the Depression, but it got a boost during World War II for experiments in rocketry. During the fifties, JPL developed a satellite that, according to legend, could have beaten Sputnik into orbit by a few months and irrevocably changed the space race – if it had been launched. Throughout the sixties, JPL solidified its reputation as the place for robotics – unmanned spacecraft destined for the moon and the planets – but it lacked the high profile of the Johnson Space Center in Houston or the Kennedy Space Center in Florida.

      All that changed with the advent of the new Mars program in 1992, when a new generation of employees began streaming into JPL, reinvigorating the place. Unlike many of the old timers, they hadn’t come out of the military or the aerospace industry, they were just out of grad school, and had grown up watching the space program on television. They were young, and they weren’t burdened by the past. The men wore earrings and pony tails instead of military buzz cuts, and tie-dyed t-shirts replaced white polyester short-sleeve button-down shirts and narrow black ties. But that was just the men. Many of the new recruits were women, and among them was Jennifer Harris.

      Growing up on her family’s farm in Fostoria, Ohio, Jennifer never expected to explore Mars or to become a flight manager for a Mars mission. She wanted to be a concert pianist. She played the piano, the saxophone, marimbas, bassoon, trumpet, tuba; she was a one-woman band. On the other hand, she loved math and competed successfully in county-wide math competitions. Astrophysics excited her imagination, especially black holes; she loved just thinking about them. In the summer before her senior year in high school, she went to music camp, where she realized that her survival as a concert pianist would depend on her ability to practice every waking moment, and she wasn’t sure that was what she wanted to do with her life. She also wanted to travel, to meet people; she was even thinking of becoming a missionary. When MIT accepted her, she went into a mild state of shock. Eventually, she chose to major in Aerospace Engineering – partly because it sounded like the coolest thing she could do and partly because her father had tested missiles for NASA when he was younger, and she had come of age hearing his tales of countdowns, halts, and explosions. Or maybe the picture of a rocket on a wall in the den of her home influenced her decision. After graduation, she went to work for the Jet Propulsion Laboratory.

      Even after she arrived at JPL, Jennifer was restless. They were designing spacecraft on spec, hoping to get funding from Congress, and most projects never did. If a project actually received a green light, the lead time was awfully long. As she toiled away at her subsystems, she couldn’t see where her little cog fit into the machine, or if there even was a machine. She began to ask herself, “Is this all there is?”

      She was single and didn’t have any serious ties to Pasadena or JPL. She chose to take a leave of absence, without assurance that a job would be waiting for her when she returned, if she returned. She still wanted to see the world and meet people, so she decided to do missionary work in Russia. She was assigned to Sevastapol, in the Crimea, near the Black Sea, where the conditions were unbelievably grim. There was no hot water, and they lived in cement buildings that were always cold and damp. A lot of the population were flat-out atheists. The economic situation was horrendous. She was paid about $30 a week, which made her among the wealthiest citizens of the town. Everyone around her was subsisting in a barter economy, using coupons instead of cash; one Snickers bar, for instance, cost 2,000 coupons. She and her friends based everything on the cost of a Snickers bar, but that didn’t help keep track of finances, because the inflation was incredible. Pretty soon that Snickers bar cost 8,000 coupons, then 16,000. People who had saved throughout their entire lives lost their fortunes overnight when the ruble