凌日

2004年6月8日金星凌日Hα色球观测

H α Chromospheric Observations of the Venus Transit on June 8,2004

Halley彗星的凌日效应及其等离子体彗尾中磁场机理的探讨

The Transit Effect of Halley Comet and An Approach to the Machanism of Magnetic Field in Its Plasma Tail

寻找离地球较近的适居带行星将是凌日系外行星勘测人造卫星（TransitingExoplanetSurveySatellite，简称TESS）的任务。这种卫星将于2017年发射。

Finding Goldilocks planets closer to home will be the job of TESS , the Transiting Exoplanet Survey Satellite , scheduled to be launched in 2017 .

从地球我们可以看到水星和金星凌日；由火星上，还可以看到地球凌日。

From Earth , one may see transits of Mercury and Venus .

这是因为这次的金星凌日不会经常发生。

That 's because these transits of Venus don 't happen often .

我们正在谈论的是，金星凌日。

We 're talking about the transit of Venus .

下一次金星凌日将发生在2117年12月11日。

The next transit of Venus will take place on Dec. 11 , 2117 .

他们利用了一种方法，叫做凌日光谱分析法，将光线分解成各种各样的颜色。

The scientists used a method called transit spectroscopy , breaking light up into its various colours .

今年金星凌日的观测能帮助研究人员校准仪器，以便得到这些重大突破。

Observations of this year 's transit of Venus could help researchers calibrate the instruments for making these breakthroughs .

凌日开始于今晚东部时间6点以后，它只持续6小时40分钟。

The transit starts just after 6:00 pm Eastern time tonight , and it lasts for six hours and 40 minutes .

随着时间的推移，虎斑星会突然变暗，这样的亮度骤降不能归结为凌日现象造成。

Tabby 's Star dims at such extreme rates over time that the dimming cannot be attributed to an eclipsing planet .

在轨道相反的一端，凌日行星消失在主星身后，这一事件称为次凌。

At the opposite end of their orbit , transiting planets disappear behind their home star , in an event known as a secondary transit .

因为金星凌日很难用肉眼看见，在人类历史上大部份的时期，人们都不知道有这样的事情。

Because a transit of Venus is barely visible to the naked eye , for most of history humans went about their lives oblivious to such events .

另一种则是同时拍到两个凌日的物体，比如金星与恰好经过的飞机，或者是金星与低空轨道上的国际空间站；

Another category captures a double coincidence such as both Venus and an airplane simultaneously silhouetted , or Venus and the International Space Station in low Earth orbit .

宇宙中一天体（如一行星）运行到另一天体与观察者之间，使前者如同经过后者之表面；凌日

Movement of one object in space ( eg a planet ) between another and an observer , so that the first seems to pass across the surface of the second

今天，在大约7个小时的时间内，至少从我们在地球上的角度观测，金星会在太阳的前面经过。这种现象被称为金星凌日。

And today , for about seven hours , Venus will be passing in front of the sun , at least from theperspectiveof us here on Earth . It 's called thetransitof Venus .

据《羊城晚报》报道，天文爱好者可以在6月6日上午一饱眼福，观测到本世纪最后一次金星凌日。

Astronomy enthusiasts across China will be blessed to see on a spectacular transit of Venus on the morning of June 6 , the last such astronomical phenomenon in the century , Yangcheng Evening News reported .

凌日是指行星（本次是金星）运行至太阳和地球之间，因此可以观测到太阳圆盘上有一个小黑点。

A transit occurs when a planet passes directly between the sun and the Earth ; therefore the planet , in this case Venus , becomes visible and hence obscures a small portion of the solar disk .

加州一个观测凌日的人称这就像是在观察小草生长，但他补充道，这里引用他的原话：“如果你被告知草每100年才会生长，你可能会想去看它。”

One person who watched the transit in California said it was like watching grass grow , but he added , quote , " If you were told that grass only grows every 100 years , you 'd probably want to watch it . "

我们可以通过望远镜来观测凌日现象，即这些行星从恒星面前穿过并遮挡住恒星。当一颗地外行星从恒星和地球之间穿过，我们能看到恒星短暂的微光。

We can use a telescope to observe their transits , which is when they eclipse their star by passing directly in front of it from our perspective . We see the temporary dimming of the star 's light as an exoplanet passes between the star and Earth .

天文学家查找行星候选者的方法之一就是通过“凌日法”观察恒星，行星经过其母恒星表面的时候，会造成恒星亮度的略微降低，因而此法更容易发现较大的行星。

One of the few ways astronomers can locate exoplanet candidates is by observing a star and waiting for the light output to dim ever so slightly . This happens when the planet transits across the face of the star , so it 's much easier to detect larger bodies .