VND - Vu Nguyen Learn On The Go

A total eclipse of the Moon occurs during the early morning of Tuesday, August 28, 2007. The event is widely visible from the United States and Canada as well as South America, the Pacific Ocean, western Asia and Australia. During a total lunar eclipse, the Moon's disk can take on a dramatically colorful appearance from bright orange to blood red to dark brown and (rarely) very dark gray.

An eclipse of the Moon can only take place at Full Moon, and only if the Moon passes through some portion of Earth's shadow. The shadow is actually composed of two cone-shaped parts, one nested inside the other. The outer shadow or penumbra is a zone where Earth blocks some (but not all) of the Sun's rays. In contrast, the inner shadow or umbra is a region where Earth blocks all direct sunlight from reaching the Moon.

If only part of the Moon passes through the umbra, a partial eclipse is seen. However, if the entire Moon passes through the umbral shadow, then a total eclipse of the Moon occurs. For more information on how, what, why, where and when of lunar eclipses, see the special web page lunar eclipses for beginners.

Times and Phases of the Total Lunar Eclipse of August 28, 2007

From start to finish, August's lunar eclipse lasts about three hours and thirty-three minutes (not including the penumbral phases which are very difficult to see). The partial eclipse begins as the Moon's eastern edge slowly moves into the Earth's umbral shadow. During the partial phases, it takes just over an hour for the Moon's orbital motion to carry it entirely within the Earth's dark umbra. The color and brightness of the totally eclipsed Moon can vary considerably from one eclipse to another. Dark eclipses are caused by volcanic gas and dust which filters and blocks much of the Sun's light from reaching the Moon. But since no major volcanic eruptions have taken place recently, the Moon will probably take on a vivid red or orange color during the total phase. After the total phase ends, it is once again followed by a partial eclipse as the Moon gradually leaves the umbral shadow.

The total phase of a lunar eclipse is called totality. At this time, the Moon is completely immersed within the Earth's dark umbral shadow. During the August 28 eclipse totality will last 90 minutes. This is less that the maximum possible duration of 107 minutes (see: Total Lunar Eclipse of July 16, 2000).

The major phases of the eclipse occur as follows (all times are GMT or Greenwich Mean Time). The partial eclipse commences with first umbral contact at 08:14 GMT. Totality begins at 09:52 GMT and lasts until 11:22 GMT. The partial phases end at 12:23 GMT. Eclipse times for time zones in the United States and Canada are shown in the following table.

The table above provides times of the major eclipse phases for North American time zones, Hawaiian Standard Time and Greenwich Mean Time (GMT). Eclipse times for other time zones can be calculated by taking the difference between local time and Greenwich and adding it to the tabulated GMT times. If you live somewhere that does not use Daylight Saving Time in the summer months, you can convert the above times for your time zone from Daylight Saving Time to Standard Time simply by subtracting 1 hour. For more information, see Time Zones and Daylight Saving Time.

Note that most of the USA is observing Daylight Saving Time during the eclipse. However, Arizona remains on Mountain Standard Time year-round and does not use Daylight Saving Time. Eclipse times for Arizona are the same as those for Pacific Daylight Time

To determine the Moon's altitude at each stage of the eclipse as seen from your city or location, see Javascript Lunar Eclipse Explorer. This web page allows you to calculate the viewing circumstances of all lunar eclipses visible from your city over a five-thosuand year period.

Read this full at  http://sunearth.gsfc.nasa.gov/eclipse/LEmono/TLE2007Aug28/TLE2007Aug28.html