今天是近400年來最黑暗的一天?

The rare lunar eclipse has fallen on the winter solstice at the Greenwich meridian of December 21, 2010, making the day the "darkest" ever in 372 years。

It is well known that winter solstice is the shortest day of the year in the Northern Hemisphere because the North Pole of the Earth is pointing away from the sun. A total lunar eclipse also occurs when the sun, Earth and moon are almost exactly in line, leaving the full moon appear much dimmer than usual。

Interestingly, after this year, people have a long time to wait until we have a December full moon and then a lunar eclipse occur on the same date as the solstice: December 21, 2094! However, the 2094 eclipse will not be visible from the Western Hemisphere, but will be able to be seen from Europe, Africa and much of Asia。

Then when was the last time that we had a total lunar eclipse occur on the same date as the winter solstice? The answer is nearly four centuries ago - December 21, 1638.

2010年12月21日正午時分(格林尼治時間)，月全食和冬至時間偶遇，於是372年來最“黑暗”的日子就此誕生。

衆所周知，北半球在冬至這一天白日最短，因爲地球北極距離太陽最遠。而太陽、地球和月亮又幾乎處於一條線上，月全食出現，導致滿月比往常晦暗許多。

有意思的是，今年過後，要想再看到12月滿月、月全食和冬至趕到一起，人們就得等很長一段時間了：2094年12月21日！但是，2094年的月全食在西半球無法觀測到，但在歐洲、非洲和亞洲的大部分地球都可以看到。

那麼上一次人類在冬至時節看到月全食是什麼時候呢？答案是近4個世紀以前——1638年12月21日。