Total Lunar Eclipse at Moonset

Were you one of the estimated 300 people who gathered at Tasca soccer field in North Scituate to view last March's total lunar eclipse, only to be disappointed by the clouds that did a much better job of covering the Moon than the Earth's shadow did? Well, you may remember I mentioned you would have another opportunity in August.

Well believe it or not, that date, August 28, is almost upon us. Unfortunately even with good weather we will be not be able to view totality. The circumstances are a little different this time around. Totality for us in southern New England will begin just as the Moon is setting in the west at dawn. So this event will not be for you folks who are not morning people!!

Yes, this eclipse will be a total lunar eclipse. If you want to see the eclipse in its entirety you will have to travel west of the Rocky Mountains. For us locally it will begin when the Moon slides into the Earth's light shadow called the penumbra at 3:52 am, Eastern Daylight Time (EDT). This phase is so dim it is undetectable. Perhaps a half hour later a keen-eyed observer will notice a subtle shading along the top left edge of the lunar surface. (Imagine the Moon as a clock face. Darkening should appear around the ten o'clock position.) Just prior to the Moon entering the Earth's dark umbral shadow should one notice that the moonlight looks somewhat subdued.

The Moon will enter the Earth's dark umbral shadow at 4:51 am EDT. This begins the partial eclipse phase with the Moon just 12 degrees above the west-southwest horizon. The dark shadow will also appear in the ten o'clock position, then it will proceed to cover the Moon from the upper left to the lower right (four o'clock position). Totality begins at 5:52 am EDT when the lunar surface is completely within the Earth's dark umbral shadow. This eclipse should be a "dark" one, for the Moon will slide deep into the shadow, unlike last March's event.

Unfortunately we won't be able to determine that here because sunrise is at approximately 6:05 am EDT and moonset at approximately 6:07 am EDT. And, bright twilight will certainly spoil the view well before that. In addition, you'll need an unobstructed west-southwest horizon.

Totality will last for 90 minutes for observers farther out in the western states. That's a long time. I think some folks will get a little impatient waiting for sunlight to once again strike the lunar surface.

So if you want to watch the partial phase before the Moon dips below the horizon, I think you will be able to follow it about 90 - 95% of the way through. Otherwise, head out west!

Also, do some web surfing prior to the event to see if anyone will be providing a webcast of this total lunar eclipse. I've watched several astronomical events from my home computer that we were unable to observe first-hand in Rhode Island for one reason or another.

If you do find a webcast, here are times (all times are EDT - Eastern Daylight Time) of the remaining important phases:

Mid-totality: 6:37 am Totality ends: 7:22 am Partial ends: 8:24 am Penumbra ends: 9:22 am - not detectable

If you have binoculars or a telescope, now will be the time to put them to good use. The more optical aid an observer uses, the more detail one will discern. Even if you don't have access to expensive equipment, don't despair. Mother Nature provided you with a pair of the most valuable observing tools -- your eyes! Use them to follow the progress of this beautiful event.

So, are you a morning person? If the weather is favorable make every effort to see this beautiful celestial show when you can observe in comfortable conditions. The next one on February 21, 2008, will be seen in its entirety for us in New England, but it will most likely be very cold. At least totality during that event will be at a reasonable hour: 10:00 pm EST.

Good luck, keep your eyes to the skies.