(Getty) "The Earth's shadow has this reddish glow inside it, which comes from the Earth's atmosphere, so when the moon is totally in the shadow you get almost a brownish-red appearance," Prof Watson explains. "That's caused by light being scattered into the Earth's atmosphere, into that shadow." April's total lunar eclipse will look slightly different than your typical blood moon, however, in part due to its close proximity to us. Professor Watson describes it as more of an ombre blood moon. "This one won't be uniform [in colour] because it's so near the edge of its shadow that it'll probably be lighter on one side than it is on the other."