《每日邮报》、《大西洋焦点视野》、《大图网》金星凌日
本帖最后由 人与自然 于 2012-6-7 22:54 编辑http://www.dailymail.co.uk/sciencetech/article-2155140/Transit-Venus-2012-Spectacular-seen-time-2117.html
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-13787B5A000005DC-565_964x455.jpg Enthralling: Venus is silhouetted as it crosses in front of the sun as it sets behind the Kansas City, Missouri skyline on Tuesday, June 5, 2012 美国密苏里州堪萨斯城的金星凌日
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-1379036A000005DC-204_964x604.jpg Planet Venus is seen as a black dot as it transits across the Sun during sunrise in Sofia, Bulgaria on June 6, 2012保加利亚索菲亚的金星凌日 本帖最后由 人与自然 于 2012-6-7 18:05 编辑
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-137878CE000005DC-425_964x939.jpg Dramatic: This image provided by NASA shows the Solar Dynamic Observatory's ultra-high definition view of Venus on it's transit, an event which will not occur for another 105 yearsNASA的金星凌日
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-1378775D000005DC-957_964x642.jpg Impressive: This image provided by NASA shows the Solar Dynamic Observatory's ultra-high definition view of Venus, black dot at top center, passing in front of the sun on Tuesday, June 5, 2012NASAS的金星凌日图
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-1378471B000005DC-342_964x571.jpg Bright: This is just one frame of an astonishing short video put online by NASA of Venus passing the sun NASAS的金星凌日图 本帖最后由 人与自然 于 2012-6-7 18:05 编辑
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-1378CE8A000005DC-421_964x483.jpg A composite sequence photo of the steps of the entire transit of Venus seen over the sky of Seoul, South Korea, 6 June 2012韩国首都汉城市看到的金星凌日全过程
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-1379822E000005DC-931_964x528.jpg NASA had all eyes on the transit, ensuring to capture the images for posterity - if they had messed the shot up, it's a 105-year-wait for the next oneNASA拍摄的金星凌日
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-137878CE000005DC-425_964x939.jpg Dramatic: This image provided by NASA shows the Solar Dynamic Observatory's ultra-high definition view of Venus on it's transit, an event which will not occur for another 105 yearsNASA拍摄的金星凌日 本帖最后由 人与自然 于 2012-6-7 18:15 编辑
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-137849F1000005DC-12_964x648.jpg Scene: A view of the Sun as the planet Venus passes in between the Sun and the Earth in New York, New York, USA, 05 June 2012纽约的金星凌日
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-1379C0CC000005DC-669_964x645.jpg Many ways to view it, many places in the world to see it: Professor Hashim Ahmed Yousif al-Sayed, dean at the College of Science at the University of Bahrain, projects the sun's image for students巴林大学的哈西姆教授在讲解金星凌日
THE SALFORD SIDE STREET WHERE MODERN ASTRONOMY WAS BORN: HOW THE TRANSIT WAS FIRST SEEN IN 1639
1639年街边的金星凌日观测，标志着现代天文学诞生
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-13793510000005DC-267_964x523.jpg Ford Madox Brown's 'Crabtree watching the Transit of Venus in 1639' shows how Crabtree captured the transit - a groundbreaking achievement for the time
福特·马多克斯·布朗1639年观看金星凌日，这种方式在当时具有开创性
本帖最后由 人与自然 于 2012-6-7 18:20 编辑
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-1378CFF7000005DC-639_964x614.jpg Worldwide fascination: The planet Venus makes its transit across the Sun as seen from Kathmandu on June 6, 2012加德满都的金星凌日
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-1378C42F000005DC-730_964x653.jpg Morning breaks: An observer looks through a telescope during sunrise in Vienna维也纳的观测者
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-1378675F000005DC-220_964x648.jpg Mesmerising: Spectators at Edgewater Park in Cleveland watch the sun set as the planet Venus crosses the upper right portion of the star, Tuesday, June 5, 2012天文迷在美国俄亥俄州克利夫兰Edgewater 公园中观看金星凌日 本帖最后由 人与自然 于 2012-6-7 18:26 编辑
http://i.dailymail.co.uk/i/pix/2012/06/06/article-0-13783EBB000005DC-527_964x721.jpg Last-in-a-lifetime: In this photo made using a red filter, Venus begins to pass in front of the sun, as visible from from Overland Park, Kan. on Tuesday美国堪萨斯州欧弗兰帕克公园
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-1378AB01000005DC-632_964x552.jpg Impressive: A bird sits atop one of the domes of the landmark Taj Mahal as Venus, top left, begins to pass in front of the sun, as visible from Agra, India, Wednesday, June 6, 2012印度泰姬陵圆顶尖上的金星凌日 本帖最后由 人与自然 于 2012-6-7 18:27 编辑
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-1378D21C000005DC-480_964x600.jpg The planet Venus makes its transit across the Sun as seen from Kathmandu加德满都的金星凌日
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-137905BB000005DC-306_964x583.jpg Venus is seen as a dot as it transits across the Sun on June 6, 2012 outside Sarajevo萨拉热窝的金星凌日
本帖最后由 人与自然 于 2012-6-7 18:29 编辑
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-1378664F000005DC-655_964x702.jpg Show: The planet Venus crosses the upper right portion of the sun as seen from Edgewater Park in Cleveland on Tuesday, June 5, 2012美国克利夫兰的金星凌日
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-137846FE000005DC-210_964x416.jpg Rarity: A view of the Sun as the planet Venus passes in between the Sun and the Earth in New York, New York, USA, 05 June 2012纽约的金星凌日 本帖最后由 人与自然 于 2012-6-7 18:30 编辑
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-13784D90000005DC-201_964x573.jpg Drawing near: In this handout image provided by NASA, the SDO satellite captures the approach of Venus before it transits across the face of the sun on June 5, 2012 from spaceNASA的金星凌日
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-1378374B000005DC-603_964x963.jpg Rare: Handout image courtesy of NASA shows the planet Venus at the start of its transit of the Sun, June 5, 2012. One of the rarest astronomical events occurs on Tuesday and Wednesday when Venus passes directly between the sun and Earth, a transit that won't occur again until 2117
NASA的金星凌日，下一次金星凌日是发生在2117年 本帖最后由 人与自然 于 2012-6-7 18:40 编辑
一组全球天文迷观看金星凌日的照片
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-1378730A000005DC-196_964x652.jpg Fascinated: Eight-year-old Alex Olling smiles as he uses makeshift sunglasses to watch Venus crossing the sun's face on June 5, 2012 as seen from College Park, Maryland美国马里兰州的八岁小男孩（对比之下，中国的天文科普之落后，实在是太过分了）
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-137850CF000005DC-682_964x639.jpg Stunned: A man uses a sun observation glass to watch the transit of Venus across the face of the sun on June 5, 2012, in Medellin, Antioquia department, Colombia哥伦比亚
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-137838E3000005DC-597_964x641.jpg Curious: People use solar glasses to view the transit of Venus across the face of the sun on June 5, 2012 from Riverside Park on the west side of Manhattan in New York纽约
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-137839C0000005DC-382_964x603.jpg Technique: Astronomer Raminder Samra attempts to get the view of Venus crossing the Sun using a shadow on a piece of paper and the telescope at the MacMillan Southam Observatory in Vancouver, British Columbia June 5, 2012加拿大不列颠哥伦比亚省温哥华的天文学家 Raminder Samra正在记录
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-137849E1000005DC-879_964x501.jpg Preparation: Hong Kong stargazers use a special telescope to observe the transit of Venus along the Victoria Habour中国香港
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-13797714000005DC-988_964x628.jpg Early risers turn out to see Venus transit across the sun from Wimbledon Common in the early hours of this morning温布尔顿(英格兰东南城市) ，著名的温布尔登网球公开赛举办地 本帖最后由 人与自然 于 2012-6-7 18:44 编辑
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-1378333A000005DC-316_964x680.jpg Spectacle: Venus begins to pass in front of the sun, as visible from New York, Tuesday, June 5, 2012 纽约
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-13784767000005DC-17_964x653.jpg Vision: Venus, upper right, transits the sun as seen through a dark glass from Quito, Ecuador, Tuesday, June 5, 2012厄瓜多尔首都基多
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-13783811000005DC-749_964x745.jpg Sight: Venus (top, R) crosses the sun's face as seen from Havana on June 5, 2012古巴首都哈瓦那
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-13785F4D000005DC-301_964x603.jpg Special: The small black dot seen at the top right of the sun is the planet Venus, as it transits across the face of the sun Tuesday, June 5, 2012, as seen from Mt. Trashmore in Virginia Beach, Va
美国弗吉尼亚海滩的金星凌日 本帖最后由 人与自然 于 2012-6-7 19:10 编辑
FROM CAPTAIN COOK TO NASA: HOW VENUS HAS WATCHED US TRANSIT INTO AN AGE OF SCIENCE从库克船长美国宇航局：从肉眼到科学的金星观测史，也是美国科学的发展史（中国落后的科技制度很难接受这种不立即产生效益的科学）
http://i.dailymail.co.uk/i/pix/2012/06/05/article-2154835-137579CC000005DC-659_964x638.jpg From sea adventurer to space explorer: NASA explorer Don Pettit will follow a prestigious list of travellers who turned their eyes upwards to follow the transit throughout history从海洋探险道太空探索，NASA“探险家”Don Pettit 将追随著名的天文探索科学家们，继续研究历史上的金星凌日 本帖最后由 人与自然 于 2012-6-7 22:45 编辑
HOW THE TRANSIT OF VENUS ANSWERED THE MOST PRESSING ASTRONOMICAL QUESTIONS IN HISTORY
金星凌日的观测史，揭开了很多天文之谜
编者按：英国的天文科普就是做得好，还仔细介绍了金星凌日的观测史及作出卓越贡献的科学家。对科学的重视，奠定了英国能够在世界成为日不落帝国的一个基础。http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-02FEBC850000044D-928_472x600.jpg
Visionary: Edmond Halley, a member of The Royal Society, predicted that on June 6, 1761, Venus would traverse the burning disc of the sun for about six hours远见卓识的爱德蒙·哈雷（1656年10月29日-1742年1月14日，Edmond Halley），英国天文学家、地质物理学家、数学家、气象学家和物理学家，把牛顿定律应用到彗星运动上，并正确预言了那颗现被称为哈雷的彗星作回归运动的事实。1742年1月14日逝世于伦敦，终年86岁。哈雷也预言了1761年6月6日的那次金星凌日，时间是6个小时。
For centuries, Venus held the key to the most pressing astronomical quest of the age: the size of the solar system.
In 1716, British astronomer Edmond Halley had called upon scientists to unite in a project spanning the entire globe. He predicted that on June 6, 1761, Venus would traverse the burning disc of the sun for about six hours.
If several people at different locations across the globe measured and timed this celestial rendezvous, they could calculate the distance between Earth and sun: the base unit for all distances in the solar system and the holy grail of astronomy.
The only problem was that transits of Venus only occur in pairs, eight years apart, but with an interval of more than a century before they are seen again. After this year, the next transit is not until December 2117.
When Halley asked his international colleagues to rally, only one transit had ever been observed.
Knowing he would not be alive to orchestrate this global cooperation – a fact he lamented ‘even on his deathbed’ while holding a glass of wine – all he could do was place his trust in future generations.
His gauntlet was taken up when hundreds of astronomers joined the transit project in the 1760s.
At a time when it took six days to travel from London to Newcastle, dozens of them travelled to remote outposts of the world to observe the phenomenon, laden with clocks, huge telescopes and other instruments.
Many risked their lives. With the Seven Years’ War tearing Europe apart, they were even sent into war zones.
They made for strange adventurers: most of their lives were an endless round of dull routine, spending nights under the open sky or engaging in complex computations.
The scientific world was electrified. The observations were the most ambitious scientific project ever planned, because the astronomers needed to watch the transit simultaneously from both the northern and southern hemispheres.
Venus’s path would be shorter or longer across the sun according to each viewing station. With the help of relatively simple trigonometry, the distance between sun and Earth could be calculated, but only if the astronomers shared their results afterwards.
The expeditions were organised by the scientific societies of Europe including the Royal Society in London. They sent Nevil Maskelyne, later Astronomer Royal, to St Helena – a lone speck of land in the South Atlantic.
With him he took an assistant, trunks full of instruments and more than 100 gallons of wine and rum.
Charles Mason and Jeremiah Dixon, later famed for the Mason-Dixon Line, left Britain for Sumatra, but within four days they were attacked by a French warship.
The two refused to continue but the Royal Society threatened they would be prosecuted as mutineers ‘with the utmost Severity of Law’ unless they pressed on.
那一年，21岁的哈雷对将要发生在1761年的金星凌日作了预报。他明白，自己是无法亲自看到那年的金星凌日了。但哈雷相信，只要通过观测金星凌日得到了金星的视直径，并且知道金星的公转周期，则太阳视差可以容易地由开普勒第三定律推算出来。太阳系中只有两颗行星为我们提供了做这种计算的机会，另一颗是水星，但由于它离太阳比金星近，而且体积又小，相比之下远没有金星易于观测。“因此我们一再托付那些充满好奇心的星空探索者，当我们的生命结束了，观测便委托给了他们。”哈雷在1716年给英国皇家学会的论文中说道：“他们是那些留心我们的间隙，精神饱满地投身于这些观测事业的人。”
1761年，天文学家按照哈雷给出的预测纷纷前往合适的观测点观测金星凌日。他们从大约70个观测点得到的数据印证了哈雷生前的预言，并在人类历史上第一次较为准确地计算出了天文单位的长度。但是这个结果仍然远没有哈雷预计的那样乐观，因为各个观测点的天气不一定合作，并且天文学家也无法以足够的精度确定观测地点的经度。另外，哈雷在他的计算中也犯了点错误，并不是他预言的所有地点都能够看到那次金星凌日。
http://i.dailymail.co.uk/i/pix/2012/06/06/article-2155140-0035D34A00000190-956_472x351.jpg
Even Captain James Cook got involved, taking the Endeavour into the uncharted emptiness of the South Pacific甚至连当时身处南太平洋的库克船长也投入了精力，努力研究这一现象。 Some astronomers waded waist-deep through icy rivers; others saw their ships wrecked by tropical storms. On the day of the transit, June 6, 1761, about 250 official observers at more than 100 locations pointed their telescopes to the sky. But instead of swiftly moving across the sun, Venus lingered at the edge for up to a minute, making exact timing impossible.
They had one more chance, on June 3, 1769. Once again astronomers were dispatched across the world. Catherine the Great mounted eight expeditions across the vast Russian empire.
Astronomers from Britain, Austria, Switzerland and Russia travelled to the Arctic, where their brandy froze and clocks stopped.
The British even sent Captain James Cook and the Endeavour into the uncharted emptiness of the South Pacific to follow the transit from Tahiti.
Five astronomers died and many more faced unimaginable hardship. One French scientist travelled thousands of miles, facing bloody battles, dysentery and hurricanes only to be defeated by clouds.
When he returned home after 11 years, he had twice failed to see the transit, his heirs had declared him dead and divided up his estate, and he had lost his job.
It took years to collect the global data, but eventually the distance between Earth and sun was determined within a range of 92,900,000 to 96,900,000 miles – very close to today’s figure of 92,960,000 miles.
Impressive, but even more importantly, it was the beginning of international scientific collaboration - and an important landmark in scientific history, when astronomers faced enemy attacks, deadly diseases and all kinds of adverse conditions when they united to measure the heavens
以下翻译来自新浪，与上述英文内容差不多
http://tech.sina.com.cn/d/2004-06-08/1344372803.shtml
差不多每隔120年左右，一个黑点就会穿越一次太阳。这个墨黑的小点近乎一个完美的圆，但它并不是普通的黑点，因为并不是每个人都能见到这个黑点的。而作为历史上最伟大的航海家和探险家之一詹姆士·库克，也就是蜚声世界的库克船长也与金星凌日有一段不解之缘。
库克船长奉命出征
1782年8月12日，库克船长带领“奋进号”从英国港口城市普利茅斯港起锚，向塔希提岛的方向驶去。塔希提岛是南太平洋的一个岛屿，一年前刚刚被欧洲人“发现”，那里荒芜人烟，尚未开发，当时，就连地图绘制员可能也不知道地球的那个角落是否存在大陆。
对于库克而言，那次航行的困难程度绝不亚于现代人探索月球或火星。他要带领“奋进号”在浩瀚数千英里的广阔海洋上航行，寻找一块方圆只有20英里的陆地，而当时他们没有如全球定位系统(GPS)一样的导航设备，甚至连块精确的手表都没有。而在航行途中，危险的暴风雨会在毫无征兆的情况下忽然出现(事实也确实如此)。一些未知的生命体也在海洋深处等待着。库克当时已完全预料到船上可能会有一半船员回不到英国。
但库克知道，这种冒险还是值得的，因为这次出航不仅能寻找大陆，还能观测难得一见的金星凌日。库克在航海日志中写道：“(1782年8月12日)下午2点，我们起锚远行，船上共有94人。”“奋进号”年轻的英国植物学家约瑟夫·班克斯的思想更加浪漫，他写道：“我们离开欧洲，向天堂驶去，不知道要多长时间，也许永远吧。”他们的任务是在1769年前到达塔希提岛，然后落户于岛上，建立一个天文台，观测金星凌日现象，希望通过金星凌日的观测计算出太阳系的规模。而正是为了实现这一科学愿望的英国皇家学院为库克此行提供了经费。
太阳系的规模是18世纪科学界最主要的难题之一，与目前的暗物质和暗能量本质的问题差不多。在库克那个年代，天文学家只知道绕太阳公转的6颗行星，而没有发现天王星、海王星和冥王星。另外，他们也只知道这些行星的相对间距。以木星为例，它与太阳的距离是它与地球之间距离的5倍，但它们之间的距离到底有多远？它们的绝对距离是多少，这一切在当时还是未知数。
但金星是揭开这一谜底的关键。埃德蒙·哈雷爵士在1716年便意识到这一点。因为从地球上看，金星偶尔会穿越太阳。它就像墨黑的圆盘一样，缓慢地穿过太阳黑子。哈雷推断，如果从地球上不同地方观测到金星凌日现象出现的开始和结束的时间，天文学家就有可能运用视差原理计算出地球与金星的距离，然后还能测算出太阳系中剩余星体的规模。
但问题是金星凌日实在罕见，每243年大约会出现4次，这种天文现象出现的规律通常是8年、121.5年，8年、105.5年，以此循环。哈雷本人在有生之年就没有机会见到金星凌日。一个国际研究小组曾在1761年计算出金星凌日的时间，但由于天气和其他因素，他们计算出的数据大多不准确。如果库克和其他人在1769年未能观测到金星凌日，那么地球上所有的天文学家在1874年下一次"金星凌日"出现之前，都有可能去世了。
残酷的海上之旅
库克的那次远行经常被比作一次太空探险任务。托尼·霍维茨在描写库克旅行的《蓝色纬度》里写到：“‘奋进号'肩负的任务不仅一次发现之旅，它还是测试最新理论和最新科技的实验室，其重要性可与今天的太空飞船相媲美。”
尤其是“奋进号”的船员就如同海军与“航海的灾难”——坏血病--的斗争过程中的豚鼠(常被用来做实验)。人体内只能储存相当于6周左右的维生素C，一旦这些维生素C用完，水手将会普遍感到疲劳，甚至牙床腐烂、大出血。在18世纪，一些船只通常有一半船员死于坏血病。“奋进号”装载了各种各样用于实验的食品，库克强迫船员吃泡菜和麦芽汁等一些东西。如果有谁拒绝吃，就会遭到鞭打。
据霍维茨说，事实上，在那段日子，任何库克平均几天就会用鞭子抽打他的船员。在1769年到达塔希提岛时，库克他们已经向西连续航行了8个月，所用时间相当于现代宇航员在前往火星途中所耗费的时间。当“奋进号”航行到合恩角时，已经有5名船员失去了生命，另一名绝望的水手在“奋进号”随后在太平洋航行的10周时间中跳海自杀。由于“奋进号”是成角度向塔希提岛航行的，因此极易受到风暴的袭击。此外，“奋进号”没有与任何“控制中心”有联系，同时又没有提前警告风暴即将来临的卫星气象图像，航行途中可谓是危险重重。不过库克独出心裁，他用沙漏导航，用打结的绳索测算“奋进号”的速度，用六分仪和年历，再通过观察星星估计“奋进号”的位置。这既机智又充满危险。
引人注目的是，他们在1769年4月13日，也就是金星凌日出现前大约2个月终于到达了塔希提岛。库克在航海日志中写道：“此时我们只有少数几个人上了伤兵名单... 船员们都普遍非常健康，这主要归功于吃泡菜。”然而，库克和他的船员们对塔希提岛非常陌生，这可能就像我们现在对火星一样。但在塔希提岛上生存并不需要“太空服”，相反，岛上相当舒适，有人类生活所需的必需品。岛上的居民也非常友好，渴望与库克他们进行交易。班克斯认为这“是世外桃源最真实的写照...是一个人想象中的理想家园。”但是，塔希提岛的植物群、动物群、风俗和习惯与英国的完全不同，这种差异简直到了令人惊讶的地步。“奋进号”的船员既陶醉其中，又对此感到好奇。
留下的观测纪录并不多
无怪乎在1769年6月3日金星凌日现象最终出现那一天，库克和班克斯对此的描述只有寥寥数语。他们用从英国带来的特殊望远镜，观测到金星成了一个小黑点，在眩目的太阳盘面上慢慢穿过，但这种现象却无法与塔希提岛本身的魅力相比。班克斯的航海日志用622个字描述了那天的金星凌日现象，其中只有不超过100字是描述金星的。
这主要是因为班克斯当时正在对他与塔希提岛国王塔洛和国王的妹妹努娜早餐谈话以及那天晚些时候“三位漂亮的女士”拜访他等事情进行记录。班克斯在谈到金星时说：“我与塔洛国王、努娜和他们的几位主要随从一同去了观测站，与同事们一起观测。我们让他们看金星穿越太阳的情景，并让他们理解我们此行的目的。之后，他们离开了，我也跟他们一起走了。”塔洛国王或班克斯是否对金星凌日留下深刻印象，班克斯对此没有记录。
库克的描述稍微详细一些：“那天可以说是天遂人愿，晴空万里，非常适宜观测。我们具备了我们所希望的观测金星凌日整个过程的所有优势：我们能非常清楚地看到金星周围的大气或朦胧的阴影，但这也干扰了我们看到金星与太阳接触的精确时间。”“金星周围朦胧的阴影”一直是个大问题。穿过金星大气的强烈阳光使金星圆盘边缘显得很模糊，使库克测算金星凌日出现时间的精确度降低。正是由于这个原因，库克测算的金星凌日出现时间与“奋进号”上的天文学家查尔斯·格林的一些数据不相符，他们观测到的金星凌日出现时间大约相差有42秒。
库克和格林都观测到了“黑滴效应”。在金星接近太阳的边缘时——计算金星凌日出现时间最关键的时刻--太阳边缘一侧的黑色区域好像慢慢地接触到金星。你也可以把拇指和食指靠得非常近，对“黑滴效应”进行演示：把两根手指放在眼前，然后逐渐缩小手指间的距离。在两根手指就要快碰在一起之前，你会看到手指之间的细缝有个暗色带。约翰·威斯特法尔在本月写给《天空与望远镜》杂志上指出：“这只是两个模糊的由明变暗的梯度加在一起所产生的结果”“黑滴效应”(比如金星大气的模糊现象)使得天文学家很难指明金星凌日开始和结束的时间。
“黑滴效应”不仅对塔希提岛上的库克是个问题，而且对于全世界所有的观测者都是问题。事实上，即使世界各地的天文学家做出了很大努力，他们(包括库克)在地球上76个观测点都对1769年那次金星凌日现象进行了观测，但由于不十分准确，不足以测算太阳系的规模。直到19世纪天文学家使用照相技术记录下一组金星凌日的照片时，他们才计算出太阳系的大小。
观测反而成了一件“小事”
库克当时并没有过于注意那些事，因为他还有许多事情需要做。来自英国皇家海军的密令命令他在观测完金星凌日后马上离开塔希提岛，在塔希提岛和新西兰之间寻找大陆或大片土地。在第二年的大部分时间里，“奋进号”一直航行在南太平洋上寻找大陆。
18世纪的一些科学家宣称，为了平衡北半球出现的人口高速增长而导致的土地相对减少的局面，人类必须寻找适合人居住的大陆。而当时“奋进号”上的船员甚至一度近两个月没见到陆地。就连库克也猜测可能并不存在未探明的土地或未知的“南半球陆地”。在行进过程中，库克遇到了勇猛的新西兰毛利人和澳大利亚土著人，并发现了数千英里长的新西兰和澳大利亚海岸线。而“奋进号”还曾与澳大利亚大堡礁相撞，差一点沉没。
后来，库克在雅加达中途停留了10周，对“奋进号”进行大修，当时7名水手死于坏血病。雅加达人口稠密，疾病到处蔓延。库克本来打算尽快离开那里，但因修船耽误了太长时间，结果，包括天文学家查尔斯·格林在内的人一开始便随“奋进号”(后来又有8人加入)航行的38人死亡，其中大多数是死于在雅加达感染上的疾病。霍维茨写到：“‘奋进号'40%的伤亡率在当时并不希奇。事实上，库克后来还因为自己表现出来的对船员健康异常的关心而受到称赞。”
1771年7月11日，“奋进号”返回英国港口迪尔。幸存下来的船员环游了整个地球，他们记录了数千种植物、昆虫和动物，遇到好几个新的种族，而且也一直没有放弃寻找大陆的努力。这是一次史诗般的航行，观测金星凌日反而成了库克探险行程中一件“小事”，由于过分陶醉于塔希提岛的风土人情以及受到“黑滴效应”的影响，他观测的结果并不理想。但正是由于那次航行，人们将金星与库克联系起来。事实上，也许我们可以说观测此次金星凌日的最佳理由便是因为詹姆士·库克。
现在，我们将看到这种百年不遇的天文现象，因此千万不要错过。本月6日，将再次出现金星凌日。届时我们可以通过网上或广播了解金星凌日，也可通过望远镜亲自观测。仔细观测金星那墨黑的圆盘如何在太阳上慢慢经过，这同时可以使你回到一个不同的时间和不同的地点：1769年的塔希提岛，一个部分地球还有待探索的时代。难道你会错过这样的机会吗？ (编译／任秋凌） 本帖最后由 人与自然 于 2012-6-7 23:01 编辑
以下来自《大西洋月刊》焦点视野。
感觉效果还是比每日邮报的要强大，毕竟是专业的图片新闻网站！
http://www.theatlantic.com/infocus/2012/06/the-2012-transit-of-venus/100313/
http://cdn.theatlantic.com/static/infocus/venus060612/s_v01_RTR3367C.jpg Venus moves across the Sun in this image captured by Japan's satellite Hinode, on June 6, 2012. One of the rarest astronomical events occurred yesterday, when Venus passed directly between the sun and Earth, a transit that won't occur again until 2117. (Reuters/JAXA) http://cdn.theatlantic.com/static/infocus/i/lnk.jpg
Hinode卫星，又称“Solar-B”或“日出”卫星，是由日美欧共同研制的太阳观测卫星，其拍摄的金星凌日
http://cdn.theatlantic.com/static/infocus/venus060612/v01_RTR3367C.jpg Venus moves across the Sun in this image captured by Japan's satellite Hinode, on June 6, 2012. One of the rarest astronomical events occurred yesterday, when Venus passed directly between the sun and Earth, a transit that won't occur again until 2117. (Reuters/JAXA)
同上
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Details on the relative sizes and distances involved in yesterday's transit of Venus. (Sun Image by NASA SDO) # http://cdn.theatlantic.com/static/infocus/i/lnk.jpg
NASA，关于本次金星凌日的，比较详细的几个数据，如图中所示
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Planet Venus, visible as a black dot, in transit across the Sun near the Victory Tower in Chittorgarh, India, on June 6, 2012. (AP Photo/Atish Aman) # http://cdn.theatlantic.com/static/infocus/i/lnk.jpg
印度Chittorgarh 胜利塔的金星凌日 本帖最后由 人与自然 于 2012-6-7 23:06 编辑
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A girl uses a sun observation glass to watch the transit of Venus in Medellin, Colombia, on June 5, 2012. (Raul Arboleda/AFP/Getty Images) # http://cdn.theatlantic.com/static/infocus/i/lnk.jpg
美国哥伦比亚麦德林的一个小女孩正在观看金星凌日
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An amateur astronomer observes Venus in a clearing in a grove near Jena, Germany, on June 6, 2012. (AP Photo/Candy Welz) # http://cdn.theatlantic.com/static/infocus/i/lnk.jpg
德国耶拿的天文爱好者在观测
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Venus in transit across the Sun, seen from in New Delhi, on June 6, 2012. (Manan Vatsyayana/AFP/Getty Images) # http://cdn.theatlantic.com/static/infocus/i/lnk.jpg
印度新德里的金星凌日 本帖最后由 人与自然 于 2012-6-7 23:10 编辑
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Venus before the Sun, seen through clouds above New Delhi, on June 6, 2012. (Manan Vatsyayana/AFP/Getty Images) # http://cdn.theatlantic.com/static/infocus/i/lnk.jpg
印度新德里
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Venus appears as a black dot in front of the Sun, over Amman, Jordan, on June 6, 2012. (Reuters/Ali Jarekji) # http://cdn.theatlantic.com/static/infocus/i/lnk.jpg
安曼(约旦王国首都)的金星凌日
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Josh Romney and his wife Amanda Romney watch the planet Venus transit across the Sun outside Salt Lake City, Utah, on June 5, 2012. (Reuters/Jim Urquhart) # http://cdn.theatlantic.com/static/infocus/i/lnk.jpg
美国犹他州的一对夫妻，Josh Romney和他的妻子 Amanda Romney 正在观看，令人脸上洋溢着天文迷的幸福 本帖最后由 人与自然 于 2012-6-7 23:17 编辑
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A jet passes in front of the Sun, as Venus is transiting, as seen from Huntington Beach, California, on June 5, 2012. Original here. (CC BY Jim Nista) # http://cdn.theatlantic.com/static/infocus/i/lnk.jpg
加利福尼亚亨廷顿海滩的金星凌日
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In the Wilhelm-Föster Observatory in Berlin, a woman points to the shadow of Venus on a projected image of the Sun, on June 6, 2012. (AP Photo/Christoph Soeder) # http://cdn.theatlantic.com/static/infocus/i/lnk.jpg
德国柏林的观测者正在观察金星凌日的映像
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An image from NASA's orbiting Solar Dynamics Observatory shows the full disk of the Sun, as Venus passes in front of it on June 5, 2012. Also visible are numerous sunspots. (NASA/SDO) # http://cdn.theatlantic.com/static/infocus/i/lnk.jpg
NASA一颗名为太阳动力学观测卫星的轨道卫星拍摄的照片，金星仿佛一颗大黑子 本帖最后由 人与自然 于 2012-6-7 23:19 编辑
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The planet Venus transits at sunset, seen over the Great Salt Lake outside Salt Lake City, Utah, on June 5, 2012. (Reuters/Jim Urquhart) # http://cdn.theatlantic.com/static/infocus/i/lnk.jpg
美国犹他州盐湖城的金星凌日
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A bird comes into land atop one of the domes of the landmark Taj Mahal as Venus begins to pass in front of the Sun, as visible from Agra, India, on June 6, 2012. (AP Photo/Kevin Frayer) # http://cdn.theatlantic.com/static/infocus/i/lnk.jpg
印度泰姬陵圆顶上的鸟与金星凌日
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Hong Kong skygazers use special filters on telescopes and binoculars to observe the transit of Venus along the Victoria Harbour in Hong Kong, on June 6, 2012. (AP Photo/Vincent Yu) # http://cdn.theatlantic.com/static/infocus/i/lnk.jpg
香港天文迷为金星凌日而疯狂 本帖最后由 人与自然 于 2012-6-7 23:23 编辑
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Ultra-high-definition view of Venus as it passes out of the disk of the Sun, seen by the Helioseismic and Magnetic Imager aboard NASA's orbiting Solar Dynamics Observatory. (NASA/SDO HMI) # http://cdn.theatlantic.com/static/infocus/i/lnk.jpg
NASA一颗名为太阳动力学观测卫星的轨道卫星的日球层磁场观测仪拍摄的高清晰金星凌日
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Venus in silhouette, seen between the Earth and Sun, from NASA's orbiting Solar Dynamics Observatory, on June 5, 2012.
(NASA/SDO) # http://cdn.theatlantic.com/static/infocus/i/lnk.jpg
同上
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Residents of Sarajevo use a telescope to see Venus transiting across the Sun on June 6, 2012 outside the Bosnian capital. (Elvis Barukcic/AFP/Getty Images) # http://cdn.theatlantic.com/static/infocus/i/lnk.jpg
萨拉热窝疯狂的天文迷
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