For centuries, transits of Venus have drawn explores and astronomers alike to the four corners of the globe. And you can put it all down to the extraordinary polymath Edmond Halley. In November 1677, ...

上面报道中的transit of Venus就是“金星凌日”。金星轨道在地球轨道内侧，某些特殊时刻，地球、金星、太阳会在一条直线上，这时从地球上可以看到金星就像一个小黑点一样在太阳表面缓慢移动，天文学称之为“金星凌日”。