Skywatchers will get a rare triple treat on January 31st.  A supermoon, a blue moon and a total lunar eclipse.

Even without the supermoon, it's the first blue moon total lunar eclipse in the USA since March 1866, less than a year after the Civil War ended, according to USA Today.

A blue moon, which occurs about every 2 and a half years, is another term for the second full moon in a single calendar month.  January's first full moon occurred Jan. 1.

Though the exact moment of this full moon is 8:37 a.m. ET Jan. 31, the moon will appear plenty full for a day or two before and after that.