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<font size="5"><strong><font face="Times New Roman">Investigating the asteroids</font></strong></font><font size="3"><font face="Calibri">Dawn's early light</font></font><br /><font size="6"><strong><font size="6"><font face="Times New Roman">A mission to the asteroid belt will visit leftovers from the solar system’s formation <br /></font></font></strong></font><font size="3"><font face="Times New Roman">Jul 14th 2011 | from the print edition </font></font><br /><font face="Calibri"><font size="3">Dimly seen through the mists of the deep<br /></font></font><br /><font size="3"><span style="color:#ff0000;"><font face="SimSun">计时</font></span><span style="color:#ff0000;"><font face="Times New Roman">1</font></span><span style="color:#ff0000;"><font face="SimSun">(</font></span><span style="color:#ff0000;"><font face="Times New Roman">317 words</font></span><span style="color:#ff0000;"><font face="SimSun">)</font></span><span style="color:#ff0000;"><br /></span></font><br /><font size="3"><font face="Times New Roman">LAST week all eyes were on the Kennedy Space Centre in Florida, as NASA’s space shuttle blasted off on its final mission (see </font></font><a href="http://www.economist.com/node/18956096" target="_blank"><span style="color:#0000ff;"><font size="3"><font face="Times New Roman">article</font></font></span></a><font size="3"><font face="Times New Roman">). Meanwhile, hundreds of millions of kilometres away, another NASA spacecraft was approaching its destination. If all goes to plan, then on July 16th <em>Dawn</em>, the largest robotic probe ever launched by America’s space agency, will drop into orbit around Vesta, the second-largest member of the asteroid belt.</font></font><br /><font size="3"><font face="Times New Roman">Though a mission to the asteroids may lack the glamour of sending probes to Mars and the moons of Saturn, these tiny planetlets have long fascinated astronomers, for they offer a window on the earliest years of the solar system. </font></font><br /><font size="3"><font face="Times New Roman">When the sun formed, some 4.5 billion years ago, it was surrounded by a disk of gas and dust. During the next few million years, lumps of that disk stuck together to form the familiar eight planets of the modern solar system. Some lumps, however, were left over. And a lot of them are concentrated in the asteroid belt, between the orbits of Mars and Jupiter, where the combined gravities of Jupiter and Saturn seem to have gathered them from other parts of the solar system. There, they have crashed repeatedly into one another to form fragments of various sizes.</font></font><br /><font face="Times New Roman"><font size="3">Small asteroids (a few of which have been visited already by space probes) are often little more than piles of dust and chondrules, the spherical pebbles of rock that formed from dust which melted in the heat of the young sun. Larger bodies such as Vesta, though, are more interesting. Vesta’s size (it is around 520km in diameter) and density make it massive enough for its gravity to keep it roughly spherical, like a proper planet. Another thing that makes Vesta planetlike is that it is split into distinct layers. The evidence suggests it has a nickel-iron core like the Earth’s, overlain by a rocky mantle. <br /></font></font><br /><font size="3"><font face="Times New Roman"></font></font><br /><br /><font size="3"><span style="color:#ff0000;"><font face="SimSun">计时</font></span><span style="color:#ff0000;"><font face="Times New Roman">2</font></span><span style="color:#ff0000;"><font face="SimSun">(</font></span><span style="color:#ff0000;"><font face="Times New Roman">236 words</font></span><span style="color:#ff0000;"><font face="SimSun">)</font></span><span style="color:#ff0000;"><br /></span></font><br /><font size="3"><font face="Times New Roman"> art of that evidence comes from its density and part from hundreds of chunks of rock, in the form of meteorites, that have been examined by Earth-bound scientists. These rocks are believed to be the result of an asteroidal prang that happened many millions of years ago and left a crater 460km across, which dominates Vesta’s southern hemisphere. The reason they are thought to come from Vesta is that the asteroid has an unusual and characteristic spectrum. It shares this with a number of smaller asteroids whose orbits suggest they were spalled off in the collision, and with about 5% of the meteorites which fall to Earth. Such meteorites look like igneous rocks from Earth—hence the belief that Vesta has a mantle.</font></font><br /><strong><font size="3"><font face="Times New Roman">The rocket’s blue glare</font></font></strong><br /><font size="3"><font face="Times New Roman">After spending a year in orbit around Vesta, <em>Dawn</em> will perform a trick rare in space travel—it will reignite its engines and head off to orbit another body. Ceres, at about 960km in diameter, is the largest asteroid. <em>Dawn</em> is due to arrive there in 2015. </font></font><br /><font size="3"><font face="Times New Roman">Ceres, too, is spherical and probably divided into core and mantle, though the mantle seems to be wetter than that of Vesta. Indeed, Ceres may have ice caps and a thin atmosphere. But it has been luckier than Vesta—and almost every other asteroid—in avoiding collisions, and has thus not yielded a huge crop of meteorites for Earth-bound scientists to examine.</font></font><br /><font size="3"><font face="Times New Roman"></font></font><br /><br /><font size="3"><span style="color:#ff0000;"><font face="SimSun">计时</font></span><span style="color:#ff0000;"><font face="Times New Roman">3</font></span><span style="color:#ff0000;"><font face="SimSun">(</font></span><span style="color:#ff0000;"><font face="Times New Roman">295 words</font></span><span style="color:#ff0000;"><font face="SimSun">)</font></span><span style="color:#ff0000;"><br /></span></font><br /><font size="3"><font face="Times New Roman"><em>Dawn</em> is able to perform the trick of moving from one asteroid to another thanks to its ion-rocket engines, pioneered on an earlier NASA mission called <em>Deep Space One</em>. Unlike conventional rockets, which use high-energy chemical reactions to force a stream of hot gas out of the engine, ion rockets employ electric fields to accelerate charged particles of fuel (in this case, xenon gas) out of the back of the spacecraft.</font></font><br /><font size="3"><font face="Times New Roman">Ion engines give a pretty feeble kick.<em> Dawn</em>’s produce 92 millinewtons of thrust, something like a fiftieth of the amount in a smallish firework rocket. The exhaust velocity, though, is enormous—more than ten times that of a chemical rocket—and this makes ion propulsion extremely efficient. Though an ion engine could never lift a spacecraft out of Earth’s gravity well, once that craft is in deep space the futuristic-looking blue glow of its exhaust can take it to parts that chemical engines find much harder to reach. <em>Dawn</em> started off with 450kg of propellant, and even at maximum throttle its engines use only a quarter of a kilo a day. </font></font><br /><font size="3"><font face="Times New Roman">The arrival of <em>Dawn</em> at Vesta also marks another significant achievement. If the craft does manage to go into orbit it will mean that working man-made satellites are circling and scrutinising eight bodies in the solar system: the sun, Mercury, Venus, Earth, the moon, Mars and Saturn, as well as Vesta. That gives comfort to those who fear that the end of the shuttle programme might mean a wider loss of interest in the exploration of space. Whether it does—and the new record proves to be the high-water mark of unmanned space exploration—or whether <em>Dawn</em>’s arrival proves merely a staging post on the road to greater things, remains to be seen.<font face="SimSun"><br /></font></font></font><br /><strong><font size="5"><font face="Times New Roman,serif"> anama's economy<br /></font></font></strong><br /><font size="3"><font face="Times New Roman,serif">A Singapore for Central America?<br /></font></font><br /><strong><font size="6"><font face="Times New Roman,serif">Latin America’s fastest-growing country has set its sights high. First it needs a government as impressive as its economy <br /></font></font></strong><br /><font size="3"><font face="Times New Roman,serif">Jul 14th 2011 | <em> ANAMA CITY </em>| from the print edition</font></font><font size="3"><font face="Times New Roman,serif"><br /></font></font><br /><font size="3"><span style="color:#ff0000;"><font face="SimSun">计时</font></span><span style="color:#ff0000;"><font face="Times New Roman">4</font></span><span style="color:#ff0000;"><font face="SimSun">(</font></span><span style="color:#ff0000;"><font face="Times New Roman">280 words</font></span><span style="color:#ff0000;"><font face="SimSun">)</font></span><span style="color:#ff0000;"><br /></span></font><br /><font size="3"><font face="Times New Roman">ON A humid stretch of Pacific coast in one of the poorest parts of the Americas, somebody seems to have misplaced a chunk of Manhattan. The 50-storey skyscrapers of Panama City jut out of the jungle like nowhere else in low-rise Central America. Panama’s smart banks, open economy and long queues of boats at its ports have caused many to compare it to Singapore, another steamy success story. Panama’s president, Ricardo Martinelli, made his country’s first state visit there in 2010 and later said, “We copy a lot from Singapore and we need to copy more.”</font></font><br /><font size="3"><font face="Times New Roman"> anama is not even one-fifth as rich as its Asian model on a per-person basis. But Singapore would envy its growth: from 2005 to 2010 its economy expanded by more than 8% a year, the fastest rate in the Americas. The IMF expects it to grow by over 6% a year during the next five years. Panama will soon overtake Costa Rica and Venezuela in GDP per head. Accounting for purchasing power, it is one of the five richest countries in mainland Latin America.</font></font><br /><font face="Times New Roman"><font size="3">An 80km (50-mile) channel of water has played a big part. In 2010 the Panama Canal’s revenues were $2 billion (7.5% of GDP). This year they are up by a quarter, thanks to more traffic and higher tolls. The canal and Panama’s business-friendly regulations have spawned big insurance, finance and legal industries and endowed Panama with the world’s biggest merchant navy, at least on paper. A free-trade zone in Colón, at the canal’s Atlantic end, has lured the regional bases of firms like Procter & Gamble. Last year Colón and Balboa, Panama’s Pacific gateway, became Latin America’s two busiest ports.<br /></font></font><br /><span style="color:#ff0000;"><font size="3"><font face="Times New Roman"></font></font><br /></span><br /><font size="3"><span style="color:#ff0000;"><font face="SimSun">计时</font></span><span style="color:#ff0000;"><font face="Times New Roman">5</font></span><span style="color:#ff0000;"><font face="SimSun">(</font></span><span style="color:#ff0000;"><font face="Times New Roman">284 words</font></span><span style="color:#ff0000;"><font face="SimSun">)</font></span><span style="color:#ff0000;"><br /></span></font><br /><font face="Times New Roman"><font size="3"> anama’s import tariffs are among the lowest in Latin America, and the country has received foreign direct investment worth nearly 9% of GDP, the largest share on the continent. A $5.3 billion expansion of the canal for bigger ships is due to be completed in 2014. Separately, the government has begun a five-year, $13.6 billion investment plan, focusing on schools, hospitals, sewerage, roads and a metro for the congested capital. Pensions for the poor and a universal scholarship will help to reduce inequality, which is among the worst in the Americas. In indigenous areas, 85% of people cannot afford enough calories for an adequate diet—even as the champagne flows in the capital’s casinos.<span style="color:#ff0000;"><br /></span></font></font><br /><font size="3"><font face="Times New Roman">And the “Latin Singapore” remains deeply un-Singaporean in two more ways. One is education, where Panama’s spending has not yielded good results. The PISA study, a test of 15-year-olds, places Panama 63rd out of 65 economies, behind the likes of Albania. Singapore comes fourth.</font></font><br /><font size="3"><font face="Times New Roman">Bad schools are common in Latin America. But in a country of 3.5m the shortage of skilled workers is acute, discouraging foreign firms from investing and slowing their growth. Mario Cuevas, an economist at the Inter-American Development Bank, says that Panama’s Singaporean plan is “a realistic goal, not just a hope”. But he notes that whereas Singapore’s success rests on high productivity, Panama’s growth has come from accumulating capital in the form of infrastructure.</font></font><br /><font face="Times New Roman"><font size="3">More serious are weak institutions. Singapore is reckoned one of the world’s least corrupt countries. Panama, in contrast, is not even the cleanest in Central America, according to Transparency International, a pressure group. The World Economic Forum, a business-minded think-tank, scolds Panama for its corruptible public officials and lack of judicial independence.<br /></font></font><br /><font size="3"><span style="color:#ff0000;"><font face="SimSun">自由阅读</font></span><br /></font><br /><font size="3"><font face="Times New Roman">Mr Martinelli, a supermarket magnate, is not helping. Leaked cables from the United States embassy warned that he “may be willing to set aside the rule of law in order to achieve his political and developmental goals”, and said he had asked for American help in bugging his opponents. The popular president is accused of meddling with the Supreme Court and of conspiring to oust the attorney-general. He now wants to introduce a presidential run-off and reduce the time before being eligible to stand for re-election, which would suit his own political interests.<br /></font></font><br /><font size="3"><font face="Times New Roman">Doubts about the rule of law have already hurt the country. Some foreign construction firms did not bid for the Panama City metro contract, fearing the tender was rigged. (A free-trade deal with the United States, expected to be approved soon by America’s Congress, will make procurement more transparent.) In June a posh part of Panama City, where Donald Trump is building a 70-storey hotel and residential complex, was flooded with sewage because planning laws had been ignored.</font></font><br /><font size="3"><font face="Times New Roman">The biggest long-term worry is that the Panama Canal Authority, an autonomous state agency admired for its efficient operation, could be captured by the government and run as a short-term cash-cow. Pemex, Mexico’s creaking state-owned oil monopoly, is sometimes cited as a cautionary tale. Unless Panama cleans up its government, it runs the risk of becoming the next Mexico rather than the next Singapore. </font></font> |
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