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For more lengthly information about the moon and lunar eclipse's:
From NASA (I realize this diagram is a repeat from other postings I've done, but it's better explained here with the attached text):
"Times and Phases of the Total Lunar Eclipse of February 20/21, 2008
From start to finish, February's lunar eclipse lasts about three hours and twenty-six 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 February 20 eclipse totality will last just under 50 minutes. This is quite a bit less than the last total lunar eclipse ( August 28, 2007) which lasted 90 minutes.
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 01:43 GMT. Totality begins at 03:01 GMT and lasts until 03:51 GMT. The partial phases end at 05:09 GMT. Eclipse times for time zones in the United States and Canada are shown in the following table.
Total Lunar Eclipse of February 20, 2008
North America Other
Event EST CST MST PST AST GMT GMT+1h GMT+2h
Partial Eclipse Begins: 08:43 pm 07:43 pm 06:43 pm 05:43 pm 04:43 pm 01:43 am* 02:43 am* 03:43 am*
Total Eclipse Begins: 10:01 pm 09:01 pm 08:01 pm 07:01 pm 06:01 pm 03:01 am* 04:01 am* 05:01 am*
Mid-Eclipse: 10:26 pm 09:26 pm 08:26 pm 07:26 pm 06:26 pm 03:26 am* 04:26 am* 05:26 am*
Total Eclipse Ends: 10:51 pm 09:51 pm 08:51 pm 07:51 pm 06:51 pm 03:51 am* 04:51 am* 05:51 am*
Partial Eclipse Ends: 12:09 am* 11:09 pm 10:09 pm 09:09 pm 08:09 pm 05:09 am* 06:09 am* 07:09 am*
* Event occurs on morning of February 21, 2008
Key to Time Zones
Zone Description
EST Eastern Standard Time (GMT - 5 hours)
CST Central Standard Time (GMT - 6 hours)
MST Mountain Standard Time (GMT - 7 hours)
PST Pacific Standard Time (GMT - 8 hours)
AST Alaska Standard Time (GMT - 9 hours)
GMT Greenwich Mean Time
The table above provides times of the major eclipse phases for North American time zones 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.
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.
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Visibility of the Total Lunar Eclipse of February 20, 2008
February's lunar eclipse is well-placed for North and South America as well as Europe and Africa. Observers along North America's west coast miss the early stages of the partial eclipse because it begins before moon rise. Alaskans in Anchorage and Fairbanks experience moonrise during totality but bright evening twilight will make it difficult for sourdoughs to view the event. Western Europe and northwest Africa also see the entire eclipse. Further to the east (east Africa and central Asia), the Moon sets before the eclipse ends. None of the eclipse is visible from eastern Asia or Australia.
Preceeding and following the eclipse are hour-long penumbral phases but these are faint and quite difficult to see. The more interesting and photogenic partial and total phases always take center stage to the penumbral phases.
Map showing the global visibility of the Total Lunar Eclipse of February 21, 2008.
(Click here to see larger version of this map)
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 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 anyone located in the blue shaded region labeled Eclipse at Moonset, this means that the Moon will set while some phase of the eclipse is already in progress. The contact curves labeled P1, U1, U2, U3, U4, and P4 represent each phase of the eclipse (see the key above). If you are east (right) of a particular curve, that phase occurs after moonset and you will not see it. However, if you are west (left) of a curve, that phase occurs before moonset and you will see it (weather permitting).
For example, on the above map Turkey lies west (left) of the U3 curve (total eclipse end) and east (right) of the curve U4 (partial eclipse ends). This means that from this region, the Moon sets during the partial phases following totality.
For observers located within the second blue shaded region labeled Eclipse at Moonrise, the situation is reversed. Here the Moon rises while some phase of the eclipse is already in progress. If you are west (left) of a particular curve (P1, U1, U2, U3, U4, or P4), that phase occurs before moonrise and you will not see it. However, if you are east (right) of a contact curve, that phase occurs after moonrise 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.
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Wonderful Totality
At the instant of mid-totality (03:37 GMT), the Moon will lie in the zenith for observers in French Guiana. At this time, the umbral eclipse magnitude peaks at 1.1062.
From the diagram above, it is clear that the northern (top) edge of the Moon will dip much deeper into the Earth's shadow than will the southern (bottom) 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. A large variation in shadow brightness can be expected and observers are encouraged to estimate the Danjon value at different times during totality ( Danjon Brightness Scale). Note that it may also be necessary to assign different Danjon values to different portions of the Moon at different times.
This could be an excellent opportunity for budding astronomers and students to test their observing skills. Try recording your estimates of the Moon's brightness every ten minutes during totality using the Danjon Scale. Compare your results with your companions and classmates and discover how the Moon's appearance changes during the total eclipse. The brightness of the totally eclipsed Moon is very sensitive to the presence of volcanic dust in Earth's atmosphere. As part of a continuing research project, Dr. Richard Keen has been using reports of lunar eclipse brightnesses to calculate a history of optical thicknesses of volcanic dust layers (see: What Will 2004's Lunar Eclipses Look Like?). If you'd like to help Dr. Keen by making eclipse observations, you can contact him at Richard.Keen@Colorado.EDU.
The amount of dust and sulfur dioxide in Earth's atmosphere also has an effect on the diameter of the umbral shadow. Amateur astronomers with telescopes can make careful timings 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. A table of crater predictions identifies twenty well-defined craters useful for this purpose. For more information, see: Crater Timings During Lunar Eclipses.
An eclipse of the Moon also presents a tempting subject 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 to your camera. A typical ISO 400 speed (either digital or film) is a good choice. For more information on equipment, film, recommended exposures and additional tips, see lunar eclipse photography.
Unlike solar eclipses, lunar eclipses are completely safe to watch. Protective filters are not necessary and neither is a telescope. A lunar eclipse can be observed with nothing more than the naked eye. However, a pair of binoculars will magnify the view and make the red coloration brighter and easier to see. A standard pair of 7x35 or 7x50 binoculars is sufficient.
During the eclipse, the Moon will be in Leo. Saturn and bright star Regulus are only 3 degrees east and west, respectively, of the Moon. Geminii, Orion, Taurus and other winter constellations will occupy the south and western sky for North American eclipse watchers. viewers.
Although total eclipses of the Moon are of limited scientific value, they are remarkably beautiful events which do not require expensive equipment. They help to cultivate interest in science and astronomy in 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 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 swings through the Earth's shadow. Hope for clear skies, dress warmly and enjoy the show!"
More fropm NASA:
"Lunar Eclipse Figures
Each lunar eclipse has two diagrams associated with it along with data pertinent to the eclipse. The top figure shows the path of the Moon through Earth’s penumbral and umbral shadows. Above this figure are listed the instant of ecliptic conjunction of the Moon with the point 180° from the Sun (i.e., Full Moon) and the instant of greatest eclipse, expressed in Terrestrial Dynamical Time and Universal Time. The penumbral and umbral magnitudes are defined as the fraction of the Moon’s diameter immersed in the two shadows at greatest eclipse. The radii of the penumbral and umbral shadows, P. Radius and U. Radius, are also listed. Gamma is the minimum distance in Earth radii of the Moon’s centre from Earth’s shadow axis at greatest eclipse, and Axis is the same parameter expressed in degrees. The Saros series of the eclipse is listed, followed by a pair of numbers. The first number identifies the sequence position of the eclipse in the Saros; the second is the total number of eclipses in the series.
In the upper left and right corners are the geocentric coordinates of the Sun and the Moon, respectively, at the instant of greatest eclipse. They are:
R.A. - Right Ascension
Dec. - Declination
S.D. - Apparent Semi-Diameter
H.P. - Horizontal Parallax
To the lower left are the semi, or half, durations of the penumbral, umbral (partial), and total eclipses. Below them are the Sun/Moon ephemerides used in the predictions, followed by the extrapolated value of ΔT (the difference between Terrestrial Dynamical Time and Universal Time). To the lower right are the contact times of the Moon with Earth’s penumbral and umbral shadows, defined as follows:
P1 - Instant of first exterior tangency of Moon with Penumbra. (Penumbral Eclipse Begins)
U1 - Instant of first exterior tangency of Moon with Umbra. (Partial Umbral Eclipse Begins)
U4 - Instant of last exterior tangency of Moon with Umbra (Partial Umbral Eclipse Ends)
P4 - Instant of last exterior tangency of Moon with Penumbra. (Penumbral Eclipse Ends)
The bottom figure is a cylindrical equidistant projection map of Earth that shows the regions of visibility for each stage of the eclipse. In particular, the moonrise/moonset terminator is plotted for each contact and is labeled accordingly. The point where the Moon is in the zenith at greatest eclipse is indicated by an asterisk. The region that is completely unshaded will observe the entire eclipse, while the darkly shaded area will witness no eclipse. The remaining lightly shaded areas will experience moonrise or moonset while the eclipse is in progress. The shaded zones east of the asterisk will witness moonset before the eclipse ends, and the shaded zones west will witness moonrise after the eclipse has begun.
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Shadow Diameters and Lunar Eclipses
To compensate for Earth's atmosphere when calculating the circumstances for lunar eclipses, Chauvenet [1891] introduced an empirical enlargement of 1/50 to the diameters of the umbral and penumbral shadows . This rule has been employed by many of the national institutes in their official eclipse predictions (including the author's work at NASA). However, Danjon [1951] pointed out a flaw in this method because it applies the same relative correction to the umbra and penumbra instead of using the same absolute correction. From eclipse observations, Danjon proposed to enlarge Earth's diameter by 1/85 to compensate for the atmosphere. The umbral and penumbral shadow diameters are then calculated based on this modified geometry. The French almanac "Connaissance des Temps" has used the Danjon rule in its eclipse predictions since 1951. The resulting umbral and penumbral eclipse magnitudes are smaller by approximately 0.005 and 0.026, respectively, as compared to predictions using the traditional 1/50 rule.
Beginning with Eclipses During 2007, we use the Danjon rule in calculating lunar eclipse circumstances and magnitudes.
Danjon Scale of Lunar Eclipse Brightness
The Moon’s appearance during a total lunar eclipse can vary enormously from one eclipse to the next. Obviously, the geometry of the Moon’s path through the umbra plays an important role. Not as apparent is the effect that Earth’s atmosphere has on total eclipses. Although the physical mass of Earth blocks all direct sunlight from the umbra, the planet’s atmosphere refracts some of the Sun’s rays into the shadow. Earth’s atmosphere contains varying amounts of water (clouds, mist, precipitation) and solid particles (meteoric dust, organic debris, volcanic ash). This material significantly filters and attenuates the sunlight before it is refracted into the umbra. For instance, large or frequent volcanic eruptions dumping huge quantities of ash into the atmosphere are often followed by very dark, red eclipses for several years. Extensive cloud cover along Earth’s limb also tends to darken the eclipse by blocking sunlight.
The French astronomer André-Louis Danjon proposed a useful five-point scale for evaluating the visual appearance and brightness of the Moon during total lunar eclipses. L values for various luminosities are defined as follows:
L=0 Very dark eclipse.
(Moon almost invisible, especially at mid-totality)
L=1 Dark eclipse, grey or brownish in coloration.
(details distinguishable only with difficulty)
L=2 Deep red or rust-coloured eclipse.
(very dark central shadow, while outer umbra is relatively bright)
L=3 Brick-red eclipse.
(umbral shadow usually has a bright or yellow rim)
L=4 Very bright copper-red or orange eclipse.
(umbral shadow has a bluish, very bright rim)
The assignment of an L value to lunar eclipses is best done with the naked eye, binoculars, or a small telescope near the time of mid-totality. It’s also useful to examine the Moon’s appearance just after the beginning and just before the end of totality. The Moon is then near the edge of the shadow, providing an opportunity to assign an L value to the outer umbra. In making any evaluations, the instrumentation used and the time should both be recorded. Also note any variations in colour and brightness in different parts of the umbra, as well as the apparent sharpness of the shadow’s edge. Pay attention to the visibility of lunar features within the umbra. Notes and sketches made during the eclipse are often invaluable in recalling important details, events, and impressions.
Crater Timings During Lunar Eclipses
In 1702, Pierre de La Hire made a curious observation about Earth’s umbra. In order to accurately predict the duration of a lunar eclipse, he found it necessary to increase the radius of the shadow about 1% more than is warranted by geometric considerations. Although the effect is clearly related to Earth’s atmosphere, it is not completely understood, since the shadow enlargement seems to vary from one eclipse to the next. The enlargement can be measured through careful timings of lunar craters as they enter and exit the umbra.
Such observations are best made using a low-power telescope and a clock or watch synchronized with radio time signals. Timings should be made to a precision of 0.1 min. Record the instant when the most abrupt gradient at the umbra’s edge crosses the apparent centre of the crater. In the case of large craters like Tycho and Copernicus, record the times when the shadow touches the two opposite edges of the crater. The average of these times is equal to the instant of crater bisection.
As a planning guide, Tables 3 and 6 list 20 well-defined craters with predicted umbral immersion and emersion times during the two lunar eclipses of 2008. You should be thoroughly familiar with these features before viewing an eclipse in order to prevent confusion and misidentification. The four umbral contacts with the Moon’s limb can also be used in determining the shadow’s enlargement. However, these events are less distinct and therefore difficult to time accurately. Observers are encouraged to make crater timings and to send their results to Sky & Telescope (Sky & Telescope, 90 Sherman Street, Cambridge MA 02140-3264, USA) for analysis.
Note that all predictions presented here use Danjon's rule of shadow enlargement (see: Shadow Diameters and Lunar Eclipses). In particular, the diameter of the umbral shadow has been calculated assuming an enlargement of Earth's radius of 1/85 to account for the opacity of the terrestrial atmosphere. The effects of Earth’s oblateness have also been included.
Eclipse Altitudes and Azimuths
The altitude a and azimuth A of the Sun or Moon during an eclipse depend on the time and the observer's geographic coordinates. They are calculated as follows:
h = 15 (GST + UT - α ) + λ
a = arcsin [sin δ sin φ + cos δ cos h cos φ]
A = arctan [-(cos δ sin h)/(sin δ cos φ - cos δ cos h sin φ)]
where
h = hour angle of Sun or Moon
a = altitude
A = azimuth
GST = Greenwich Sidereal Time at 0:00 UT
UT = Universal Time
α = right ascension of Sun or Moon
δ = declination of Sun or Moon
λ = observer's longitude (east +, west -)
φ = observer's latitude (north +, south -)
During the eclipses of 2008, the values for GST and the geocentric Right Ascension and Declination of the Sun or the Moon (at greatest eclipse) are as follows:
Eclipse Date GST α δ
Annular Solar 2008 Feb 07 9.111 21.346 -15.516
Total Lunar 2008 Feb 21 10.029 10.247 10.469
Total Solar 2008 Aug 01 20.693 8.798 17.866
Partial Lunar 2008 Aug 16 21.708 21.762 -12.925
Two web based tools that can also be used to calculate the local circumstances for all solar and lunar eclipses visible from any location. They are the Javascript Solar Eclipse Explorer and the Javascript Lunar Eclipse Explorer. The URLs for these tools are:
http://sunearth.gsfc.nasa.gov/eclipse/J
http://sunearth.gsfc.nasa.gov/eclipse/J
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2008-02-20 09:30 pm (UTC)