大家对2018年初的“超级蓝血月全食”还记忆犹新吧？7月27号到28号这两天就又将有一场月全食盛宴了！这次虽然没有“蓝月亮”的卖点，却是整个21世纪时间最长的月全食！下面，一起了解一下“血月”的科学解释吧！
Before the International Space Station, before Skylab, before Sputnik, just one special satellite circled the Earth.
The moon was around before the first cells divided.
Every life form that's ever looked up has seen that same face.
Since the first humans stood and walked, it's been our big, round calendar in the sky, our constant companion.
So I guess it must have been pretty terrifying when people looked up and saw this.
Thankfully, science has taught us that a giant monster does not in fact get angry and eat the moon before painting it blood red.
It's just a lunar eclipse.
As bright as the moon looks in the night sky, what we're really seeing is sunlight, and the percent of its face that's illuminated depends on where it is in relation to the Earth.
At the point in its orbit where the moon is at its closest point to the sun, we see or rather don't see a new moon.
At the point in its orbit where the moon is farthest from the sun, we get a full moon.
