Joel 2:31 and Acts 2:20. The sun will be turned to darkness and the moon to blood before the coming of the great and dreadful day of the Lord.
On April 15, 2014, there was a total lunar eclipse.
It was the first of four consecutive total eclipses (Tetrads) in a series.
It is one of eight tetrads during the 21st century AD. As with most eclipses, the moon appeared red during the April 15 eclipse.
The red color is caused by Rayleigh scattering of sunlight through the Earth's atmosphere, the same effect that causes sunsets to appear red.