Nature之Solar eclipses as an astrophysical laborator ...

    Observations of the Sun during total eclipses have led to major discoveries, such as the existence of helium (from its spectrum), the high temperature of the corona (though the reason for the high temperature remains controversial), and the role of magnetic fields in injecting energy into—and trapping ionized gases within—stellar atmospheres. A new generation of ground-based eclipse observations reaches spatial, temporal and spectral-resolution domains that are inaccessible from space and therefore complement satellite studies.Solar eclipses occur when the Moon comes directly between the Earth and the Sun. By a happy coincidence, the Moon and Sun subtend the same angle in the sky to within 10%. As the lunar orbit is tilted by 5u with respect to the plane of the Earth’s orbit around the Sun (the ecliptic plane), solar eclipses occur only when both Moon and Sun are sufficiently near the nodes, the crossing points of the Moon’s apparent path in the sky and the ecliptic1. Such events occur at least yearly, though the region on Earth from which the totally eclipsed Sun (Fig. 1) is visible is sufficiently small that travel is usually necessary.
      在整个日蚀期间对太阳的观测可导致较多的发现，例如氦的存在(从它的光谱中发现)，高温的日冕（虽然高温的原因仍然有争议），星体大气中磁场在能量注入中的角色和抑制电离气体进入。一个新一代的地基日蚀观测相对空间观测存在些许不足，因此需要卫星辅助观测。日食的发生是当月球恰巧移动到地球和太阳之间，月球和太阳相同的倾角在10%之内。当月球轨道与地球公转轨道平面倾斜5°(黄道平面),只有当月球和太阳充分地靠近这个节点，月球路径上交叉点。此类事件每年都有发生，虽然地球上完整的视觉区域十分小，旅行还是很有必要的。   
    The original motivation for studying solar eclipses was to take advantage of rare opportunities, rather than any specific observational plan based on theory. The nature of the outer solar atmosphere was deduced during the roughly hundred years starting in 1860, when it was definitively associated with the Sun instead of being thought of as a lunar atmosphere. This ‘solar corona’ appears to people on Earth only during total eclipses (Fig. 2), forming a faint crown (Latin, corona) of light that Halley called pearly white. We now know it to be hot and ionized, that is, a plasma。
    研究日食的最初的动机利用这类比较少见的机会，而不是基于理论的任何特殊的观测计划。太阳外层组分的性质在从1860年开始的一百多年里已被诠释，当其在定义时就和太阳有关，而不是认为其一种与月亮朔望变化相似的大气结构。地球上的人们可以在整个日蚀期间看到“日冕”，其结构形似一个昏暗的皇冠（corona是拉丁文），哈雷称其为珍珠似的白色。我们现在知道日冕温度很高，而且是电离化的，也可以说其是一个等离子体。     
   Because of their dramatic nature, bringing the darkness of twilight even at midday, total solar eclipses have been noted for thousands of years. A total eclipse results in a darkening by a factor of approximately a million, meaning that the coverage of the last 1% of the everyday solar surface produces a darkening by a remaining factor of about 10,000—so the onset of darkness comes only from a change even smaller than that last 1%. Therefore, it can be deduced, even from ancient chronicles, whether a writer was inside or outside the zone of totality. Such observations have therefore been searched for and found in tablets, parchment, and other writing from Asia, the mid-East, and Europe, and then used to determine variations in the Earth’s rotation over thousands of years3,4.
      由于其戏剧性的性质，甚至在中午可以使黄昏降临，整个日食过程早在几千年前就有记录了。一次完整的日蚀导致的昏暗因素大概有一百万份之一，意味着每天太阳表面产生一次昏暗是由剩下的大约10，000之一的因素所导致，所以昏暗的到来只需一个改变，甚至小于那最后的1%。因此，可以理解，即使古老的年代记录，一个记录员是否位于日食带上。此类的观测可以被寻找且发现于记录本，羊皮纸，或者其他记录来自亚洲，中东，欧洲，然后这些记录随着时间的流逝在全球辗转3.4千年。
     本月重要天象日全食带将横扫我国，大部分的地方都能看到。
     本菜鸟趁这段有时间，翻译了Nature与日食有关的一文``俺水平很烂，不足的地方还请大大指出

   Solar eclipses as an astrophysical laboratory
    Observations of the Sun during total eclipses have led to major discoveries, such as the existence of helium (from its spectrum), the high temperature of the corona (though the reason for the high temperature remains controversial), and the role of magnetic fields in injecting energy into—and trapping ionized gases within—stellar atmospheres. A new generation of ground-based eclipse observations reaches spatial, temporal and spectral-resolution domains that are inaccessible from space and therefore complement satellite studies.Solar eclipses occur when the Moon comes directly between the Earth and the Sun. By a happy coincidence, the Moon and Sun subtend the same angle in the sky to within 10%. As the lunar orbit is tilted by 5u with respect to the plane of the Earth’s orbit around the Sun (the ecliptic plane), solar eclipses occur only when both Moon and Sun are sufficiently near the nodes, the crossing points of the Moon’s apparent path in the sky and the ecliptic1. Such events occur at least yearly, though the region on Earth from which the totally eclipsed Sun (Fig. 1) is visible is sufficiently small that travel is usually necessary.
      在整个日蚀期间对太阳的观测可导致较多的发现，例如氦的存在(从它的光谱中发现)，高温的日冕（虽然高温的原因仍然有争议），星体大气中磁场在能量注入中的角色和抑制电离气体进入。一个新一代的地基日蚀观测相对空间观测存在些许不足，因此需要卫星辅助观测。日食的发生是当月球恰巧移动到地球和太阳之间，月球和太阳相同的倾角在10%之内。当月球轨道与地球公转轨道平面倾斜5°(黄道平面),只有当月球和太阳充分地靠近这个节点，月球路径上交叉点。此类事件每年都有发生，虽然地球上完整的视觉区域十分小，旅行还是很有必要的。   
    The original motivation for studying solar eclipses was to take advantage of rare opportunities, rather than any specific observational plan based on theory. The nature of the outer solar atmosphere was deduced during the roughly hundred years starting in 1860, when it was definitively associated with the Sun instead of being thought of as a lunar atmosphere. This ‘solar corona’ appears to people on Earth only during total eclipses (Fig. 2), forming a faint crown (Latin, corona) of light that Halley called pearly white. We now know it to be hot and ionized, that is, a plasma。
    研究日食的最初的动机利用这类比较少见的机会，而不是基于理论的任何特殊的观测计划。太阳外层组分的性质在从1860年开始的一百多年里已被诠释，当其在定义时就和太阳有关，而不是认为其一种与月亮朔望变化相似的大气结构。地球上的人们可以在整个日蚀期间看到“日冕”，其结构形似一个昏暗的皇冠（corona是拉丁文），哈雷称其为珍珠似的白色。我们现在知道日冕温度很高，而且是电离化的，也可以说其是一个等离子体。     
   Because of their dramatic nature, bringing the darkness of twilight even at midday, total solar eclipses have been noted for thousands of years. A total eclipse results in a darkening by a factor of approximately a million, meaning that the coverage of the last 1% of the everyday solar surface produces a darkening by a remaining factor of about 10,000—so the onset of darkness comes only from a change even smaller than that last 1%. Therefore, it can be deduced, even from ancient chronicles, whether a writer was inside or outside the zone of totality. Such observations have therefore been searched for and found in tablets, parchment, and other writing from Asia, the mid-East, and Europe, and then used to determine variations in the Earth’s rotation over thousands of years3,4.
      由于其戏剧性的性质，甚至在中午可以使黄昏降临，整个日食过程早在几千年前就有记录了。一次完整的日蚀导致的昏暗因素大概有一百万份之一，意味着每天太阳表面产生一次昏暗是由剩下的大约10，000之一的因素所导致，所以昏暗的到来只需一个改变，甚至小于那最后的1%。因此，可以理解，即使古老的年代记录，一个记录员是否位于日食带上。此类的观测可以被寻找且发现于记录本，羊皮纸，或者其他记录来自亚洲，中东，欧洲，然后这些记录随着时间的流逝在全球辗转3.4千年。
     本月重要天象日全食带将横扫我国，大部分的地方都能看到。
     本菜鸟趁这段有时间，翻译了Nature与日食有关的一文``俺水平很烂，不足的地方还请大大指出