Night sky aficionados will get a treat later this month when a total lunar eclipse appears in the early morning hours of April 15.
During the eclipse, the Earth's shadow will darken the moon and sunlight refracted from our atmosphere will give the lunar surface a reddish cast. The so-called "blood moon" will be visible to the naked eye beginning at 1:20 AM eastern time.
As USA Todaynotes, the event marks the beginning of a "tetrad," a series of four lunar eclipses occurring over the next two years. Tetrad sequences are infrequent, but not unheard of—there will be eight of them between now and the year 2100.