The Zimbabwe Situation

The first eclipse of 2003 occurs during the early morning hours of Friday, May 16 (in the United States it occurs in the evening of the 15th), and will be visible from North and South America as well as Europe, Africa and Antarctica. During such an 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. The reason for this can be seen from the accompanying diagram.

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 the Moon passes through only part on 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.

Visibility of the Total Lunar Eclipse of May 15-16, 2003

May's lunar eclipse is well-placed for North and South America as well as western Europe and Africa

Key to Eclipse Visibility Map
P1	Penumbral eclipse begins (not visible to the eye)
U1	Partial eclipse begins
U2	Total eclipse begins
U3	Total eclipse ends
U4	Partial eclipse ends
P4	Penumbral eclipse ends (not visible to the eye)

The map above shows the exact geographic regions of visibility for each phase of the eclipse. The entire eclipse is visible from start to finish in the white (unshaded) portion of the map, while none of the eclipse can be seen from the dark gray areas.

For observers located within the second blue shaded region labeled Eclipse at Moonset,(for example, Zimbabwe) the Moon sets while some phase of the eclipse is still in progress. If you are east (right) of a particular curve (P1, U1, U2, U3, U4, or P4), that phase occurs after moonset and you will not see it. However, if you are west (left) of a contact curve, that phase occurs before moonset and you will see it (weather permitting!). All total eclipses start with a penumbral followed by a partial eclipse, and end with a partial followed by a penumbral eclipse (the total eclipse is sandwiched in the middle). Since the penumbral phases of the eclipse are so difficult to see, we will ignore them.

Times and Phases of the Total Lunar Eclipse of May 15-16, 2003

From start to finish, May's lunar eclipse lasts about three hours and fifteen minutes. 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. 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 May 15-16 eclipse totality will last about 53 minutes.

The major phases of the eclipse occur as follows (all times are GMT or Greenwich Mean Time, so add exactly two hours for Zimbabwe). The partial eclipse commences with first umbral contact at 02:03 GMT. Totality begins at 03:14 GMT and lasts until 04:07 GMT. The partial phases end at 05:18 GMT. Eclipse times for time zones in the United States and Canada, Europe and Africa are shown in the following table.

Total Lunar Eclipse of May 15, 2003
	Americas				Europe
Event	Time EDT	Time CDT	Time MDT	Time PDT	Time GMT	Time GMT+1	Time GMT+2
Partial Eclipse Begins:	22:03	21:03	20:03	19:03	02:03*	03:03*	04:03#
Total Eclipse Begins:	23:14	22:14	21:14	20:14	03:14*	04:14*	05:14#
Mid-Eclipse:	23:40	22:40	21:40	20:40	03:40*	04:40*	05:40#
Total Eclipse Ends:	00:07*	23:07	22:07	21:07	04:07*	05:07*	06:07#
Partial Eclipse Ends:	01:18*	00:18*	23:18	22:18	05:18*	06:18*	07:18#

* Event occurs on morning of May 16, 2003 # For Zimbabwe (GMT+2)

Key to Time Zones
Zone	Description
EDT	Eastern Daylight Time (= GMT - 4 hours)
CDT	Central Daylight Time (= GMT - 5 hours)
MDT	Mountain Daylight Time (= GMT - 6 hours)
PDT	Pacific Daylight Time (= GMT - 7 hours)
GMT	Greenwich Mean Time
GMT+1	Greenwich Mean Time + 1 Hour (= GMT + 1 hour)
GMT+2	Greenwich Mean Time + 2 Hours (= GMT + 2 hours)

Lunar Eclipse Diagram

From the diagram of the path of the Moon through the Earth's shadow, it is clear that the southern (bottom) edge of the Moon will dip much deeper into the Earth's shadow than will the northern (top) edge. Since the Earth's umbral shadow is darker in the center than at the edge, the Moon's appearance will likely change dramatically with time. The brightness of the totally eclipsed Moon is very sensitive to the presence of volcanic dust in Earth's atmosphere.

The amount of dust in Earth's atmosphere also has an effect on the diameter of the umbral shadow. Amateur astronomers with telescopes can make careful times of when some of the Moon's major craters enter or exit the umbra. Such observations are valuable in determining the enlargement of Earth's shadow.

An eclipse of the Moon also presents a tempting target to photograph. Since the Moon appears quite small in the sky, you'll need a fairly powerful telephoto lens (400 mm or more) or even a small telescope to attach your camera to. A typical 400 speed color film (either slides or negatives) is a good choice.

Unlike solar eclipses, lunar eclipses are completely safe to watch. You don't need any kind of protective filters. It isn't even necessary to use a telescope. You can watch the lunar eclipse with nothing more than your own two eyes. If you have a pair of binoculars, they will help magnify the view and will make the red coloration brighter and easier to see. A standard pair of 7x35 or 7x50 binoculars work fine.

Although total eclipses of the Moon are only of minor scientific value, they are remarkably beautiful events which can be seen without expensive equipment. They help to cultivate interest in science and astronomy in our children and to provide a unique learning opportunity for families, students and teachers. To the nature lover and naturalist, the lunar eclipse can be appreciated and celebrated as an event which vividly illustrates our connection and place among the planets in the solar system. The three dimensional reality of our universe comes alive in a graceful celestial ballet as the Moon dances with the Earth's shadow. May your skies be clear, dress warmly and enjoy the spectacle!

Some images and text courtesy of Fred Espenak, NASA/GSFC (sunearth.gsfc.nasa.gov/eclipse)

M. J. R.Begbie
songbird@mweb.co.zw
Hilton Observatory
Harare, Zimbabwe
17° 46' 19" S
31° 00' 06" E
Astronomy Educator
I.C.Q. Obs. Code BEG01