A moon munching monster, coming soon to your sky!

This week there will be a disruption to the orderliness of the rhythm of the skies. The full moon on Wednesday will not rise as a yellow orange ball in the east. What mysterious forces could appear to remove the moon from the sky? To our ancestors, it really was a mysterious force that removed the moon from the sky during a lunar eclipse, and they had a variety of explanations to offer!

Some cultures explained an eclipse of the moon as a fight between the sun and the moon. The Pomo Indians of the US explained that bear went for a walk along the Milky Way where he met the Moon. The Moon would not get out of the way, and so a fight ensued. During the fight, the moon disappeared from view. When the fight was over, each went his own way, and the Moon was visible again.

In China, a dragon occasionally decided to eat the moon. Other cultures imagine other monsters and assorted beasts to be dining on the moon. In parts of Mexico, people run outside during an eclipse and bang on pots and pans and make their dogs bark to frighten away this moon munching monster.

Fanciful stories and pot banging reactions may seem extreme, but when one looks at how the ancients viewed the moon, one has a better understanding of why they reacted so strongly.

To the ancients, the moon was a time keeping device. The regular cycle of the moon, from full moon to full moon provided a way of keeping track of longer periods of time than was practical using days. It was also believed among many people that the moon had an influence over us. The moon was stable and unchanging, well, at least most of the time! Then, every now and then, a lunar eclipse would occur, and the moon would disappear from the sky for a while. Never mind that it always reappeared, something horrible had to be happening to cause the moon to disappear form the sky.

A lunar eclipse occurs when the sun, earth and moon are in line, and the moon passes through the shadow of the earth. The typical total eclipse is to see the moon begin to darken, quite often turning a deep red color. As the earth's shadow moves across the lunar face it continues to dim. Gradually the moon disappears, and may be only visible as a dim reddish disk, or perhaps not at all. Then, after a while, it begins to reappear.

This eclipse will seem to be a bit different because the moon will actually rise already in eclipse. We will not see the moon become covered by the earth's shadow; it will rise completely covered by the Earth's shadow. When the moon is totally covered, it is often not entirely dark, but might be a copper or reddish color. This is because some sunlight is scattered into the shadowed area by the earth's atmosphere.

But even if the moon does stay slightly lit, it will still be a challenge to find it during totality. It will be very low in the sky where the atmosphere is thickest and makes seeing hardest. The best way to locate the moon is to watch where on the horizon it rises a few nights before the eclipse. Then you will know where to look. Totality occurs at 6:26 PM for this area, and moonrise is at 6:28 PM. The darkest part of Earth's shadow (called the Umbra) leaves the moon at 8:59 PM and the last traces of Earth's outer shadow (called the penumbra) leave the moon's face at 10:04 PM.

The further west in the US you are, the less you will see of the eclipse, and anyone west of the Mississippi river will miss it completely. And, if there are clouds in the sky? Well, we will have another chance in September, so save your pots and pans!

Constellations

The Solar System