Rare Penumbral Lunar Eclipse, page 1

The Moon is full early tomorrow as it lines up opposite the Sun in our sky. Sunlight will illuminate the entire lunar disk, giving us a brilliant nightlight from dusk till dawn. The full Moon of April is known as the Milk Moon.

The alignmnent from Sun to Earth to Moon is almost perfect this month -- but not quite. In a perfect alignment, the Moon would pass through the dark inner portion of Earth's own shadow, creating a total lunar eclipse.

But in this case, the Moon will pass just below the darkest part of the shadow. It will pass through the relatively bright outer part of the shadow, called the penumbra. That'll cause the Moon to shine just a little less brightly than normal, but not by a lot; it's hard for most of us to tell much of a difference.

Because the Moon passes through the penumbra, it's called a penumbral eclipse. It begins a little before 3 a.m. Central Daylight Time, when the penumbra first touches the lunar disk. It ends about four hours later, when the Moon completely exits the shadow. The entire event will be visible from the western half of the United States; from the eastern half, the Moon sets before the eclipse is over.

Even if you can't detect the eclipse, though, it's always nice to step outside and watch the full Moon as it lights up the night. And if you're wondering about the next total lunar eclipse, it won't come along until March of 2007.

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Verry intresting I've personally never heard of this before. It sounds perty cool even though its hard to notice but the concept is intresting. I am always facinated by astronomical phenomena and how you can witness all of these things to prove things such as the curveature of the planet and the distances and what not.