Play Live Radio
Next Up:
Available On Air Stations

Blood Moon Represents Rare Lunar Spectacle

Image of blood moon

For the second time this year, Utahns will be able to glimpse a total lunar eclipse.

On Oct. 8, the moon will pass entirely into the shadow of the earth, for the second time this year. According to Robert Bigelow, the Clark Planetarium’s Educational Program Specialist, lunar eclipses occur twice a year, in April and October.

He also said this eclipse is special because it the second in a lunar tetrad, or a series of four consecutive total lunar eclipses.

Generally, the full moon appears coppery-red during a total lunar eclipse, giving rise to the term blood moon.

Bigelow explained the cause of the moon’s vivid appearance during the lunar spectacle.

“Because Earth has an atmosphere, the air actually bends some of the light from the sun, acting like a giant spherical lens, and the light gets bent through the atmosphere to the moon,” he said. “The sun’s light is actually a mixture of all the colors in a rainbow, and the blues and violets are scattered by the air, which is also why the sky is blue. All that is left to be bent and sent to the moon are the red and orange hues.”

He added that without Earth’s atmosphere, the moon would appear completely black during the eclipse, and different levels of dust or volcanic ash in the atmosphere can affect the particular shade of red reflected by the moon.

In folklore, all full moons have a name, and Wednesday's blood moon is also known as the Hunter’s Moon. This particular full moon rises soon after sunset, and is often seen when it is lowest in the sky and there is more atmosphere between the moon and viewer.

The crimson hue of the Hunter’s Moon has given it the name blood moon. This makes tomorrow’s total lunar eclipse a blood moon for more than one reason.