An oversized ruby-colored sphere rising in the sky as a total lunar eclipse turns the normally pallid moon scarlet is enough to make some people swoon. And perhaps with good reason, as the fiery glow is the most dramatic of the three types of lunar eclipses (the other two are called partial and penumbral).
In addition, perfection is a must: A total lunar eclipse happens only when the sun, Earth and moon are perfectly lined up.
So when the moon tiptoes into the outer portion of Earth’s shadow, becoming totally bathed in the darkest part of that shadow, why isn’t the result a “lights out” for the sky? Why instead does the moon become engulfed in a light-orange to blood-red glow?
Dispatches From The Front 