<tt id="6hsgl"><pre id="6hsgl"><pre id="6hsgl"></pre></pre></tt>
          <nav id="6hsgl"><th id="6hsgl"></th></nav>
          国产免费网站看v片元遮挡,一亚洲一区二区中文字幕,波多野结衣一区二区免费视频,天天色综网,久久综合给合久久狠狠狠,男人的天堂av一二三区,午夜福利看片在线观看,亚洲中文字幕在线无码一区二区
          Global EditionASIA 中文雙語Fran?ais
          World
          Home / World / Americas

          NASA's astrobiology rover Perseverance makes historic Mars landing

          Updated: 2021-02-19 05:16
          Share
          Share - WeChat
          Perseverance rover uses its drill to collect a rock sample on Mars in this undated artistic conceptual illustration handout. [Photo/Agencies]

          LOS ANGELES - NASA's science rover Perseverance, the most advanced astrobiology laboratory ever sent to another world, streaked through the Martian atmosphere on Thursday and landed safely on the floor of a vast crater, its first stop on a search for traces of ancient microbial life on the Red Planet.

          Mission managers at NASA's Jet Propulsion Laboratory near Los Angeles burst into applause and cheers as radio signals confirmed that the six-wheeled rover had survived its perilous descent and arrived within its target zone inside Jezero Crater, site of a long-vanished Martian lake bed.

          The robotic vehicle sailed through space for nearly seven months, covering 293 million miles (472 million km) before piercing the Martian atmosphere at 12,000 miles per hour (19,000 km per hour) to begin its approach to touchdown on the planet's surface.

          The spacecraft's self-guided descent and landing during a complex series of maneuvers that NASA dubbed "the seven minutes of terror" stands as the most elaborate and challenging feat in the annals of robotic spaceflight.

          "It really is the beginning of a new era," NASA's associate administrator for science, Thomas Zurbuchen, said earlier in the day during NASA's webcast of the event.

          The entry, descent and landing (EDL) sequence of the Perseverance rover on Mars, set for Febuary 18, 2021, is shown in this undated illustration handout. [Photo/Agencies]

          The landing represented the riskiest part of two-year, $2.7 billion endeavor whose primary aim is to search for possible fossilized signs of microbes that may have flourished on Mars some 3 billion years ago, when the fourth planet from the sun was warmer, wetter and potentially hospitable to life.

          Scientists hope to find biosignatures embedded in samples of ancient sediments that Perseverance is designed to extract from Martian rock for future analysis back on Earth - the first such specimens ever collected by humankind from another planet.

          Two subsequent Mars missions are planned to retrieve the samples and return them to NASA in the next decade.

          Thursday's landing came as a triumph for a pandemic-weary United States in the grips of economic dislocation caused by the COVID-19 public health crisis.

          SEARCH FOR ANCIENT LIFE

          NASA scientists have described Perseverance as the most ambitious of nearly 20 U.S. missions to Mars dating back to the Mariner spacecraft's 1965 fly-by.

          Larger and packed with more instruments than the four Mars rovers preceding it, Perseverance is set to build on previous findings that liquid water once flowed on the Martian surface and that carbon and other minerals altered by water and considered precurors to the evolution of life were present.

          Perseverance's payload also includes demonstration projects that could help pave the way for eventual human exploration of Mars, including a device to convert the carbon dioxide in the Martian atmosphere into pure oxygen.

          The box-shaped tool, the first built to extract a natural resource of direct use to humans from an extraterrestrial environment, could prove invaluable for future human life support on Mars and for producing rocket propellant to fly astronauts home.

          Another experimental prototype carried by Perseverance is a miniature helicopter designed to test the first powered, controlled flight of an aircraft on another planet. If successful, the 4-pound (1.8-kg) helicopter could lead to low-altitude aerial surveillance of distant worlds, officials said.

          The daredevil nature of the rover's descent to the Martian surface, at a site that NASA described as both tantalizing to scientists and especially hazardous for landing, was a momentous achievement in itself.

          The multi-stage spacecraft carrying the rover soared into the top of Martian atmosphere at nearly 16 times the speed of sound on Earth, angled to produce aerodynamic lift while jet thrusters adjusted its trajectory.

          A jarring, supersonic parachute inflation further slowed the descent, giving way to deployment of a rocket-powered "sky crane" vehicle that flew to a safe landing spot, lowered the rover on tethers, then flew off to crash a safe distance away.

          Perseverance's immediate predecessor, the rover Curiosity, landed in 2012 and remains in operation, as does the stationary lander InSight, which arrived in 2018 to study the deep interior of Mars.

          Last week, separate probes launched by the United Arab Emirates and China reached Martian orbit. NASA has three Mars satellites still in orbit, along with two from the European Space Agency.

          Reuters

          Most Viewed in 24 Hours
          Top
          BACK TO THE TOP
          English
          Copyright 1994 - . All rights reserved. The content (including but not limited to text, photo, multimedia information, etc) published in this site belongs to China Daily Information Co (CDIC). Without written authorization from CDIC, such content shall not be republished or used in any form. Note: Browsers with 1024*768 or higher resolution are suggested for this site.
          License for publishing multimedia online 0108263

          Registration Number: 130349
          FOLLOW US
          主站蜘蛛池模板: 国产18禁黄网站禁片免费视频| 久久人人97超碰国产精品| 中文字幕第一区| 人人妻人人澡人人爽欧美二区| 国产一国产精品免费播放| 97精品人妻系列无码人妻| 亚洲国产欧美在线看片一国产 | 午夜性色一区二区三区不卡视频| 国产片AV在线永久免费观看| 99精品国产成人一区二区 | 日韩精品中文字一区二区| 国产一二三五区不在卡| 啪啪av一区二区三区| 亚洲午夜久久久久久噜噜噜| 青青草一区二区免费精品| 亚洲有无码中文网| 亚洲熟女片嫩草影院| 在线不卡免费视频| 久久精品夜色噜噜亚洲aa| 精品无人区卡一卡二卡三乱码| 久久精品无码一区二区无码| 亚洲国产精品久久久久秋霞| 国产av永久无码天堂影院| 精品日本免费一区二区三区| 毛片大全真人在线| 久久婷婷五月综合鬼色| 亚洲国产良家在线观看| 免费国产裸体美女视频全黄| 日韩精品视频一二三四区| 日韩秘 无码一区二区三区| 国产超碰无码最新上传| 在线人成免费视频69国产| 桃花社区在线播放| 国产亚洲精品黑人粗大精选| 综合激情丁香久久狠狠| 精品不卡一区二区三区| 国产色a在线观看| 国产内射性高湖| 久久久久久久一线毛片| 亚洲大片中文字幕久久| 日韩有码中文字幕av|