NASA天体图集20090427——0530 木卫二、土星光环等

今天开始新的一辑NASA图集，原因是它改变了主题。整体来源
http://www.nasa.gov/multimedia/imagegallery/index.html

第一楼继续留作索引。
2#~8#楼：木卫二——欧罗巴

10#~12#：威尔金斯冰架

13#~15#：奥巴马与STS-119航天飞机乘员组合影

17#~18#：土星光环在云层的投影

20#~23#:  寒冷恒星周围不同的有机物成分

24#~25#：勇气号火星漫游车驶向“冯.布劳恩”山

26#~28#：第20批国际空间站考察组成员升天

30#~32#：100亿光年外的宇宙“幽灵”     

http://www.nasa.gov/multimedia/imagegallery/image_feature_1339.html

2009.4.28
Europa
木卫二——欧罗巴表面细节

                               
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Jupiter's moon Europa has a crust made up of blocks, which are thought to have broken apart and 'rafted' into new positions, as shown in the image on the left. These features are the best geologic evidence to date that Europa may have had a subsurface ocean at some time in its past.
木卫二——欧罗巴有一张沟壑密布的糙脸，左边的放大图中，一块块的（冰）块破碎后又像木筏一般移动到新位置。这些现象是迄今为止最好的地质证据，说明木卫二的过去曾经存在地下大洋。
Combined with the geologic data, the presence of a magnetic field leads scientists to believe an ocean is most likely present at Europa today. In this false color image, reddish-brown are as represent non-ice material resulting from geologic activity. White areas are rays of material ejected during the formation of the Pwyll impact crater. Icy plains are shown in blue tones to distinguish possibly coarse-grained ice (dark blue) from fine-grained ice (lightblue). Long, dark lines are ridges and fractures in the crust, some of which are more than 1,850 miles long. These images were obtained by NASA's Galileo spacecraft during Sept. 7, 1996, Dec. 1996 and Feb. 1997 at a distance of 417,489 miles.
综合这些地质数据和存在磁场的事实，科学家相信欧罗巴至今极可能还存在液态大洋。本伪彩图中，红棕色表示由地质活动翻出的非冰物质，白色区域是Pwyll陨石坑形成时的放射状溅射物质线。蓝色调区域是冰冻平原，冰原纹理以颜色区分：暗蓝色的粗糙，亮蓝色的细密。暗长的线条是破碎而隆起的冰脊，有些甚至在卫星表面绵延1850英里（约3,000km）。本图有伽利略木星探测器于1996.9.7、1996.12和1997.2获得的图像综合而成，拍摄距离417489英里（约671,850km）。

Image Credit: NASA/JPL/University of Arizona
版权：美国宇航局、喷气推进实验室、亚利桑那州大学

PS：怎么不说是冰山而是木筏、木块什么的。一般的观点是现在木卫二表面下还可能存在大洋。——by gohomeman1

NASA的图怎么没宽屏的，不肯与时俱进？
1600X1200大图

                               
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完整大图，4110X3080，1.1MB。本图速度比较快，就贴了。
这是我见过的最清晰的欧罗巴地貌了，比APOD的那个更加精细。
http://www.nasa.gov/images/content/337344main_image_1339_full.jpg

                               
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对比图，APOD090308的木卫二（嘿嘿，我那时居然还在说美国怎么不关注妇女）
http://www.astronomy.com.cn/bbs/thread-106982-1-1.html

                               
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我们知道，由于木卫一离木星近，强大的木星起潮力使其表面处于长期活动状态。而木卫二的冰表面下面，一般认为存在水的大洋并覆盖整个星球，至于为何有液态水，放射性元素是一个原因，另一个原因勉强可算木星的强大引力。我记不清是欧洲还是美国的探测器不是要去木卫二并释放探测器探测木卫二表面下的大洋吗？

伽利略木星探测器的飞行之旅多灾多难，由于挑战者号爆炸事故，飞船发射时间被推后好几年。到了太空中，飞船的主伞——信号天线居然不能全部张开（多年不用生锈了、漏油了？），结果传输数据的速度慢了10倍还不止。好在它飞到木星前，人类的电脑技术突飞猛进，借助图像压缩软件的帮助，最后虽然传输速度很慢，但数据量大幅度压缩，还是发回了无数漂亮的照片，并发现了木星光环。
这些图片的清晰度，即使是哈勃望远镜也是远比不过的。

背景资料图，木卫二上的Pwyll陨石坑，相当年轻哦，图也是伽利略木星飞船拍的。Pwyll，据说是凯尔特人神话中的人名，不好意思，本人对这些不了解。
http://apod.nasa.gov/apod/image/0204/pwyll_gal_big.jpg

                               
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厉害~巨清晰啊~

看来这个NASA图集还是以地球为主，今天的图继续是地球上的——威尔金斯冰架
http://www.nasa.gov/multimedia/imagegallery/image_feature_1341.html

2009-05-01
Wilkins Ice Shelf

                               
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1600X1200图

                               
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The Wilkins Ice Shelf, on the western side of the Antarctic Peninsula,experienced multiple disintegration events in 2008. By the beginning of 2009, a narrow ice bridge was all that remained to connect the iceshelf to ice fragments fringing nearby Charcot Island. That bridge gave way in early April 2009. Days after the ice bridge rupture, on April12, 2009, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite took this image of the southern base of the ice bridge, where it connected with the remnant ice shelf. Although the ice bridge has played a role in stabilizing the ice fragments in the region, its rupture doesn't guarantee the ice will immediately move away.
位于南极半岛西部的威尔金斯冰架，在2008年出现加速衰退现象。2009年初，连接冰架与Charcot岛附近破碎的冰架边缘只剩下一条狭窄的冰桥。2009.4上旬，这座冰桥提供了通道。在冰桥碎裂后的2009.4.12，美国宇航局(NASA)的土地（资源）卫星使用ASTER（高级空间热辐射计的简称，包括发射计和反射计）拍摄了冰桥的南部根基图，此处冰桥还与残存的冰架相连。虽然冰桥在该区域的冰架破碎中扮演了一个稳定器的角色，它断裂后并不能保证冰块会立刻漂走。（这话貌似说反了吧，冰桥断裂后冰块如果不会漂移，冰桥怎么能算起到稳定作用呢？——译注）
With its 14 spectral bands from the visible to the thermal infrared wavelength region and its high spatial resolution of about 50 to 300 feet, ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched Dec. 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy,Trade and Industry. A joint U.S./Japan science team maintains the instrument and its data products.
拥有从可见光到热红外的14个光谱带区域和高达50~300英尺的空间分辨率，ASTER的照片用于绘制地图和监视我们星球表面的变化。ASTER是NASA于1999.12.18发射的土地卫星上5个地球观测仪器之一。仪器由日本经济产业省（工业和贸易部）制造。一个美国和日本科学家的联合团队负责维护ASTER和它的数据产品。

Image Credit: NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team
版权：美国航空航天局、戈达德太空飞行中心、日本经济产业省、日本地球遥感数据分析中心，美国/日本ASTER联合科学团队。

PS：JAROS存疑，不知道是Japan Resources Observation System Organization还是Japanese Remote Sensing Organization。
日本的上层建筑我不太了解，不知道写得对否。头晕得不得了，这么多的缩写，全部是查网络词典找出来的。——gohomeman1

完整大图，3235X2351,960kb
http://www.nasa.gov/images/content/339118main_PIA11991_full.jpg

                               
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20090502
STS-119 Crew Presents Montage to President Obama
STS-119任务乘员组与奥巴马总统合影

                               
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NASA's STS-119 space shuttle crew (from left: Joseph Acaba, Tony Antonelli, Lee Archambault, John Phillips, Richard Arnold and Steve Swanson) present President Barack Obama with a montage in the Oval Office of the White House, Friday, May 1, 2009, in Washington.
2009.5.1星期五，华盛顿特区白宫椭圆形办公室，奥巴马总统会见STS-119任务乘员组并合影留念，各位乘员姓名从略。
Image Credit: NASA/Bill Ingalls

美国航天英雄太多了，希望我们的航天英雄也越来越多！
1600X1200图

                               
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完整照片图，相机的分辨率比较高3676X2706,1.1MB
http://www.nasa.gov/images/content/339211main_200905010001HQ_full.jpg

                               
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嘿嘿，NASA的图集在周日也休息，今天恢复。总体看，这个图集以地球图片居多，5月起的地球图集将开新帖。至于这个帖，由于图片太少，继续更新下去，主要以天体类图片为主。

http://www.nasa.gov/multimedia/imagegallery/image_feature_1343.html

2009-05-04  土星光环的影子
Shadow of Demarcation

                               
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Saturn's rings cast a dramatic shadow separating the blues and greens of the planet's northern hemisphere from the creamy pastels coloringthe southern hemisphere.
土星光环投下的影子戏剧性的把土星北半球的蓝、绿色云带和南半球乳黄色云带隔开。
This mosaic combines 6 images--2 each of red, green and blue spectral filters--to create this natural colorview. The images were obtained with the Cassini spacecraft wide-angle camera on Dec. 30, 2008 at a distance of approximately 750,000 miles from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 30 degrees. Image scale is 42 miles per pixel.
本图是由6张照片合成的真彩图——红、绿、蓝滤光器各2张。这些图片由卡西尼的广角相机摄于2008.12.30，拍摄距离：离土星约75万英里；拍摄角度：与土星赤道平面约30°角；分辨率：每像素42英里。（比哈勃的ACS稍高点——译注）
Image Credit: NASA/JPL/Space Science Institute
图像版权：美国航天局、喷气推进实验室、太空科学研究所

今天的大图方向有改变，尺寸902X1868
http://www.nasa.gov/images/content/339291main_PIA11453_full.jpg

                               
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哦
厉害
佩服呀
自然的伟大

2009-05-09
NASA的这个图集貌似每周日就休息，这是周六发的艺术概念图。
New World

                               
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This artist's conception shows a hypotheticalyoung planet around a cool star. A soupy mix of potentiallylife-forming chemicals can be seen pooling around the base of thejagged rocks. Observations from NASA's Spitzer Space Telescope hintthat planets around cool stars -- the so-called M-dwarfs and browndwarfs that are widespread throughout our galaxy -- might possess adifferent mix of life-forming, or prebiotic, chemicals than our youngEarth.

Life on our planet is thought to have arisen out of apond-scum-like mix of chemicals. Some of these chemicals are thought tohave come from a planet-forming disk of gas and dust that swirledaround our young sun. Meteorites carrying the chemicals might havecrash-landed on Earth.

Astronomers don't know if these samelife-generating processes are taking place around stars that are coolerthan our sun, but the Spitzer observations show their disk chemistry isdifferent. Spitzer detected a prebiotic molecule, called hydrogencyanide, in the disks around yellow stars like our sun, but found nonearound cooler, less massive, reddish stars. Hydrogen cyanide is acarbon-containing, or organic compound. Five hydrogen cyanide moleculescan join up to make adenine -- a chemical element of the DNA moleculefound in all living organisms on Earth.

Image credit: NASA/JPL-Caltech