A blood moon is a total lunar eclipse that can cause the moon to appear red. The document discusses a rare phenomenon called a tetrad, which is a series of 4 blood moons that occur every 6 months. The last tetrad occurred in 2014-2015 and fell on Jewish holidays, as several past tetrads are believed to have coincided with significant historical events. While some think the blood moons signal the end times, the Bible indicates the world will not end for at least another 1,007 years, and urges readers to prepare by knowing Jesus rather than living unprepared.