Next live webcast: Total Lunar Eclipse of February 20-21, 2008

TOTAL LUNAR ECLIPSE
OCTOBER 27-28, 2004

Weather conditions

Photo by Peter Lawrence from England and Peter Cleary from Canada

The spectacular photograph above shows superimposed shots of the eclipsed moon taken at the same time to show the moon's parallax against the background of the fixed stars. "Both alignment images were taken at precisely 03:30 UT," explains Lawrence. "These shots were over-exposed to pick out background stars. Moments later, two 'beauty' shots were taken and pasted over the alignment shots. The result illustrates that the moon is much closer than the background stars."

Photo by Felipe Florianópolis, SC, Brazil

Photo by Sakari Ekko, Finland

Lunar Eclipse Gallery, October 27-28 2004

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ARCHIVE IMAGES OF LIVE WEBCASTS

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02:10 UT

02:44 UT

03:45 UT

03:50 UT

04:07 UT

Archive images by ASTRONOMY.no door Carsten Arnholm, Oslo, Noorwegen

Archive image by Saros Group Scientific Expeditions and AstroEduca.com from Melia Tamarindos Observatory (San Agustín - Gran Canaria - Canary Islands)

Archive image by Unione Astrofili Italiani Rocca di Papa Roma, Italia

Archive image by Unione Astrofili Italiani Oss. Astronomico Fuligni Associazone Tuscolana, Italia

Copper Moon

The Moon encounters the penumbra, the Earth's outermost shadow zone, at 17:51 Universal Time (UT). About thirty minutes later a slight dusky shading can be noticed on the leading edge of the Moon.

At 01:15 UT the Moon begins its entry into the innermost shadow zone, or umbra. For more than an hour a circular shadow creeps across the Moon's face. At 02:23 UT, the Moon will lie completely within Earth's dark shadow. It will then take on an eerie coppery tint that has often been compared with blood.

During a total eclipse the Moon shines with a orange reddish glow Photograph: Robert Smallegange (Leeuwarden, The Netherlands)

Without Earth's atmosphere, the Moon would disappear completely once immersed in the umbra. Longer wavelengths of light penetrate Earth's atmosphere better than shorter wavelengths, which is why the rising or setting sun looks reddish. In essence, the ruddy tint of a totally eclipsed moon comes from the ring of atmosphere around Earth's limb that scatters a sunset-like glow into the umbra.

During totality a ring of reddish sunlight surrounds the Earth Courtesy: Francis Reddy.

The hue actually changes from one eclipse to another, ranging from a bright coppery orange to brownish. The Moon may darken so much that it becomes all but invisible to the unaided eye. These very dark lunar eclipses often occur after exceptional volcanic eruptions.

Totality will end at 03:44 UT, when the moon's leading edge exits the umbra. The moon will leave the umbra completely at 04:53 UT, and the eclipse will end at 06:03 UT when the moon makes its last contact with the penumbra.

Path of the Moon through Earth's umbral and penumbral shadows during the total lunar eclipse of October 27-28, 2004. P1=00:06, U1=01:14, U2=02:23, U3=03:45, U4=04:54, P4=06:03 (UT). Courtesy: Fred Espenak

Crater timings

Below can be found predictions for the immersions and emersions of craters and mountains Moon. All times are in Universal Time (UT).

Immersions and emersions of craters and mountains during the eclipse

Immersion    Crater/Mountain	Emersion
    
01:15	     Riccioli		03:53
01:16        Grimaldi   	03:54
01:20 	     Billy	    	03:01
01:27        Kepler	   	03:58
01:28 	     Aristarchus	03:52
01:29	     Campanus		04:13	             
01:35	     Copernicus		04:06
01:38        Tycho		04:23
01:38 	     Pytheas		04:02
01:44 	     Timocharis		04:03
01:45 	     Harpalus		03:49
01:45 	     Bianchini		03:51
01:52 	     Manilius		04:18
01:52	     Autolyticus	04:08
01:53	     Pico		03:59
01:54 	     Piton		04:04
01:55	     Dionysius		04:26
01:55	     Plato		03:57
01:56	     Menelaus		04:21
02:00	     Plinius		04:25
02:02	     Censorinus		04:35
02:03	     Eudoxus		04:08
02:04	     Aristoteles	04:06
02:05	     Vitruvius		04:27
02:06	     Goclenius		04:42
02:09	     Messier		04:41
02:10	     Taruntius		04:38
02:12	     Proclus		04:34
02:13	     Langrenus		04:47
02:17	     Endymion		04:13

Request of observations

Richard Keen communicates:

Dear Friends -

I am writing to request observations of the brightness of the moon during the total lunar eclipse. The brightness of the moon during a total lunar eclipse is extremely sensitive to the presence of volcanic dust in the earth's atmosphere. As part of a continuing research project, I have used observed lunar eclipse brightnesses to calculate a history of optical thicknesses of volcanic dust layers (R. Keen, "Volcanic Aerosols and Lunar Eclipses", Science, 222, pages 1011-1013, 1983; Sky & Telescope, June 1984, page 512). The resulting optical thicknesses are useful to climatologists (for volcano-climate studies) and to volcanologists (for estimating total amount of material ejected by an eruption). While this total lunar eclipse is visible from Colorado, it will be rather low in the evening sky. Besides, there's no guarantee of clear skies! So, I am requesting your help.

Here's a brief description of one way to measure the brightness of a lunar eclipse:

The totally eclipsed moon is usually brighter than most comparison stars (I expect about magnitude -3 at second and third contacts, and -1.4 at mid-totality, assuming no volcanic dust present), and its brightness needs to be reduced before a direct comparison can be made. An easy way to do this is to view the moon through reversed binoculars with one eye, comparing the reduced lunar image with stars seen directly with the other eye. The estimated magnitude of the reduced moon can be adjusted by a factor depending on the magnification of the binoculars, yielding the actual magnitude of the moon. For example, reversed 10x50 binoculars will reduce the apparent diameter of the moon by a factor of 10, or its brightness by a factor of 100, or 5 magnitudes. If the reduced moon appears like a magnitude 3 star, the actual moon is 5 magnitudes brighter, or -2. The corrections for 8x, 7x, and 6x binoculars are 4.5, 4.2, and 3.9 magnitudes, respectively. These correction factors assume the stated magnification of the binoculars is correct, and neglects light loss in the optics. More accurate correction factors can be empirically derived from observations of Venus, Jupiter, or Sirius.

Observations made from the beginning to end of totality will reveal the darkening of the moon as it slips deeper into the umbra, but the most useful observations (for measuring volcanic dust) are those taken near mid-totality.

I am also interested in any and all brightness observations of past or future lunar eclipses. Any reports of Danjon L-scale values will help me compute brightnesses of older eclipses for which only L-values are available. Reports should include time(s) of observation, size of binoculars (or other method) used, and identity of comparison stars or planets.

Articles about how volcanoes can affect the brightness of a lunar eclipse:
Dull Grey or Copper-Orange: What Will 2004's Lunar Eclipses Look Like?
Report on volcanic aerosols since 1960.

Richard Keen

Next lunar eclipses

Carl Koppeschaar

Other live webcasts:

October 27-28, 2004 total lunar eclipse:

General information:

Previous webcasts organized by Astronet:

Mercury transit, May 7, 2003

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