公寓

NASA spacecraft launched to mysterious and rare metal asteroid_我的网站

回家的诱惑

一 | 随着美国中期选举的临近，时间仿佛成了特朗普最大的敌人。 CAPE CANAVERAL, Fla. -- NASA’s Psyche spacecraft rocketed away Friday on a six-year journey to a rare metal-covered asteroid.Most asteroids tend to be rocky or icy, and this is the first exploration of a metal world. Scientists believe it may be the battered remains of an early planet's core, and could shed light on the inaccessible centers of Earth and other rocky planets.SpaceX launched the spacecraft into an overcast midmorning sky from NASA’s Kennedy Space Center. Named for the asteroid it’s chasing, Psyche should reach the huge, potato-shaped object in 2029.“It's so thrilling,” said Laurie Leshin, director of NASA’s Jet Propulsion Laboratory. Added Arizona State University's Jim Bell, part of the Psyche team: “What a great ride so far.”An hour later, the spacecraft separated successfully from the rocket's upper stage and floated away, drawing applause from ground controllers.After decades of visiting faraway worlds of rock, ice and gas, NASA is psyched to pursue one coated in metal. Of the nine or so metal-rich asteroids discovered so far, Psyche is the biggest, orbiting the sun in the outer portion of the main asteroid belt between Mars and Jupiter alongside millions of other space rocks. It was discovered in 1852 and named after Greek mythology’s captivating goddess of the soul.“It’s long been humans’ dream to go to the metal core of our Earth. I mean, ask Jules Verne,” lead scientist Lindy Elkins-Tanton of Arizona State University said ahead of the launch. “The pressure is too high. The temperature is too high. The technology is impossible,” she said. “But there’s one way in our solar system that we can look at a metal core and that is by going to this asteroid.”Astronomers know from radar and other observations that the asteroid is big — about 144 miles (232 kilometers) across at its widest and 173 miles (280 kilometers) long. They believe it’s brimming with iron, nickel and other metals, and quite possibly silicates, with a dull, predominantly gray surface likely covered with fine metal grains from cosmic impacts.Otherwise, it’s a speck of light in the night sky, full of mystery until the spacecraft reaches it after traveling more than 2 billion miles (3.6 billion kilometers).Scientists envision spiky metal craters, huge metal cliffs and metal-encrusted eroded lava flows greenish-yellow from sulfur — “almost certain to be completely wrong,” according to Elkins-Tanton. It's also possible that trace amounts of gold, silver, platinum or iridium — iron-loving elements — could be dissolved in the asteroid's iron and nickel, she said. “There's a very good chance that it’s going to be outside of our imaginings, and that is my fondest hope," she said.Believed to be a planetary building block from the solar system’s formation 4.5 billion years ago, the asteroid can help answer such fundamental questions as how did life arise on Earth and what makes our planet habitable, according to Elkins-Tanton.On Earth, the planet's iron core is responsible for the magnetic field that shields our atmosphere and enables life.Led by Arizona State University on NASA’s behalf, the $1.2 billion mission will use a roundabout route to get to the asteroid. The van-size spacecraft with solar panels big enough to fill a tennis court will swoop past Mars for a gravity boost in 2026. Three years later, it will reach the asteroid and attempt to go into orbit around it, circling as high as 440 miles (700 kilometers) and as close as 47 miles (75 kilometers) until at least 2031.The spacecraft relies on solar electric propulsion, using xenon gas-fed thrusters and their gentle blue-glowing pulses. An experimental communication system is also along for the ride, using lasers instead of radio waves in an attempt to expand the flow of data from deep space to Earth. NASA expects the test to yield more than 10 times the amount of data, enough to transmit videos from the moon or Mars one day.The spacecraft should have soared a year ago, but was held up by delays in flight software testing attributed to poor management and other issues. The revised schedule added extra travel time. So instead of arriving at the asteroid in 2026 as originally planned, the spacecraft won’t get there until 2029.That’s the same year that another NASA spacecraft — the one that just returned asteroid samples to the Utah desert — will arrive at a different space rock as it buzzes Earth.___The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group. The AP is solely responsible for all content.。

二 | 眼下，他不仅面临国际局势的重重压力，国内的支持率也在不断下滑，整个局面愈发复杂。

三 | 特朗普似乎被迫在一个日益狭窄的空间内寻找出路，而每一次决策都可能影响他未来的总统宝座。特朗普在美伊关系上的政策显得十分棘手。一方面，特朗普如同一名心急的棋手，希望能够通过经济制裁来逼迫伊朗重回谈判桌。然而，他的计划并未如愿以偿。

四 | 虽然宣布了“史上规模最大的经济制裁”，但参与美国施压行动的国家寥寥无几，伊朗也明确警告将报复任何与美国联手的国家，这样的状况让外界对特朗普的财政施压能力产生了质疑。特朗普的外交举措连连受挫，不仅在美伊问题上无法取得突破，连他试图调停的黎巴嫩与以色列冲突，以及加沙地区问题，都遭遇了挫折。这一系列的问题不仅造成了特朗普在国际舞台的失分，也在民众眼中进一步削弱了他的领导力。面对这些已知的麻烦，特朗普的支持率正逐步走低，民众的不满情绪愈演愈烈。

五 | 最近，美国联邦法官推翻了特朗普暂停向75个国家的申请人发放移民签证的政策，这一事件对特朗普而言无疑是雪上加霜。他的移民政策本是为了展示其强硬立场、团结民众，但如今却被司法权力打击，导致他在即将到来的中期选举前，被贴上失信的标签。显然，特朗普意识到了自己处境的危险，强调如果共和党在选举中失败，他不光要面临弹劾，甚至连总统职位都可能不保。根据多方观察，民主党对特朗普的弹劾计划早已酝酿已久。若在中期选举中顺利获得国会控制权，他们将有更大可能发起弹劾。值得注意的是，特朗普最近的一次军事行动并没有提前通知国会，这让民主党更加抓住了把柄，称其行为“违宪”。如此一来，特朗普不仅要在外交政策上弥补失误，还需面对内部反对派的强大压力。面临越来越多的挑战和风险，特朗普或许不得不考虑妥协，通过恢复美伊谈判来寻求突破。这不仅能缓解国际紧张局势，还有助于提高其国内支持率。毕竟，无论是国际政策还是国内民生，最终都必须回归到美国民众的福祉上。另一种可能性是，特朗普决定加码对伊朗施压，甚至采取更多的军事行动。