TOTAL LUNAR ECLIPSE
FEBRUARY 20-21, 2008

On February 21, 2008 (starting February 20 in the Americas), the full Moon passed through the Earth's shadow, producing a total lunar eclipse for skywatchers throughout Europe, Africa and the Americas. At 01:43 UT the Moon begans its entry into the innermost shadow zone. For more than an hour a circular shadow creeped across the Moon's face. At 03:01 UT, the Moon was completely within Earth's dark shadow. It then took on an eerie coppery tint that could be compared with the colour of blood. Totality ended at 03:51 UT, when the Moon's leading edge exitted Earth's shadow. The moon leaved the dark shadow completely at 05:09 UT.

In The Netherlands, Belgium, Germany and Spain Astronet, Kennislink, Astroforum, Sterrenkids, Dutch Copernicus Public Observatory, Belgian Mira Public Observatory, Spanish Serviastro, Associación Argentina "Amigos de la Astronomía" in Argentina and Hochschule Offenburg in Germany organized live webcasts of the event. Most webcast were clouded out or had a partrial view of the eclipse. Only in argentina Luis Manzerola and his team of the Asociación Argentina "Amigos de la Astronomía" viewed a complete eclipse:


THE ECLIPSE OBSERVED FROM THE NETHERLANDS


In the Netherlands Bas and Brechje van Beek of Skyglory captured the eclipse through a 101mm F5.4 Genesis Tele Vue telescope using a Canon 350DH camera, sensitized for H-alpha, at 200 ASA.

Norbert Schmidt (pictured below left behind the computer) webcasted the eclipse from Copernicus Public Observatory. He took this shot of totality at 03:04 UT.

In the Netherlands many observers gathered at Copernicus Public Observatory. At times they experienced fog, but in general the eclipse could be followed untill mid-totality.

Carl Koppeschaar observing at Copernicus Public Observatory.


A VERY SUCCESSFUL WEBCAST FROM ARGENTINA


Copyright: Asociación Argentina "Amigos de la Astronomía"


Photo Galleries:

Other webcasts:

Radio and TV:


THE ECLIPSE


Copper Moon

On February 21, 2008 (starting February 20 in the Americas), the full Moon will pass through the Earth's shadow, producing a total lunar eclipse for skywatchers throughout Europe, Africa and the Americas.

A lunar eclipse occurs when the Full Moon passes through the Earth's shadow.

The Moon encounters the penumbra, the Earth's outermost shadow zone, at 00:35 Universal Time (UT). About thirty minutes later a slight dusky shading can be noticed on the leading edge of the Moon.

At 01:43 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 03:01 UT, the Moon is completely within Earth's dark shadow. It then takes on an eerie coppery tint that can be compared with the colour of 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.

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 ends at 03:51 UT, when the moon's leading edge exits the umbra. The moon leaves the umbra completely at 05:09 UT, and the eclipse ends at 06:17 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 February 20-21, 2008. Times in UT (= GMT).

Courtesy: Science@NASA/Larry Koehn. More animations at Shadow & Substance.

Request of observations

Dr. Richard Keen (Program for Atmospheric and Oceanic Sciences (PAOS), University of Colorado) is interested in brightness estimates (total visual magnitude and Danjon L values) of the moon during totality. His plan is to summarize the results from the 2003-2004 series of lunar eclipses in the Smithsonian Volcano Bulletin after this eclipse of October.

Richard Keen communicates:

Dear observer,

This is a mass mailing to all of you who have observed lunar eclipses in the past and/or have an interest in these events. Last week I gave a presentation at a climate conference which included some results of your observations, and a copy of the presentation is attached to this message.

Once again, I would be interested in hearing of your observations of this week's eclipse (Wednesday evening, February 20. on the west side of the Atlantic and Thursday morning for those on the east side of the Atlantic). Some of you may make "reverse binocular" magnitude estimates, or Danjon "L" estimates, or both. Below are some web links with information about the eclipse and about observing methods, along with links to presentations at the climate conference your observations were presented at. In summary, the recent eclipses show that the atmosphere has been clear of volcani aerosols since about 1995, and that this has contributed about 0.2 degrees to the recent warming.

Enjoy clear skies for the eclipse!
Dr. Richard Keen




Last year's total lunar eclipse (March 3-4, 2007), observed at Copernicus Public Observatory (Overveen, The Netherlands) at mid-totality. On the Danjon scale this eclipse scored between L=3 and L=4.
Photograph: Carl Koppeschaar, Nikon D200 f2.8/55mm 13 sec exposure at ISO 400.

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 (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.

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:

Crater timings

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 2% larger than warranted by geometric considerations. Although the effect is clearly related to Earth's atmosphere, it's 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 minute. The basic idea is to 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, it's recommended that you 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.

Here are predictions for the immersions and emersions of craters and mountains on the Moon:

Immersion and Emersion Times (UT) for the Total Lunar Eclipse of February 21, 2008


Immersion	Crater/mountain     Emersion

01.46 		Riccioli  	    04.06
01.48 		Grimaldi    	    04.05
01.49 		Aristarchus	    04.22
01.53           Kepler		    04.19
01.55		Billy		    04.06
01.56		Harpalus	    04.35
01.57		Bianchini	    04.36
02.00 		Pytheas   	    04.30
02.01		Copernicus	    04.27
02.03 		Timocharis	    04.36
02.05		Pico		    04.43
02.05		Plato		    04.44
02.08		Piton		    04.44
02.10		Autolyticus	    04.43
02.11		Campanus 	    04.08
02.14		Aristoteles	    04.52
02.15		Eudoxus		    04.51
02.16 		Manilius	    04.42
02.19		Menelaus	    04.46
02.23		Dionysius	    04.42
02.24		Plinius		    04.49
02.24		Endymion	    05.02
02.27		Vitruvius	    04.53
02.27 		Tycho		    04.07
02.33		Censorinus	    04.47
02.34		Proclus		    04.59
02.37		Taruntius	    04.55
02.40		Messier		    04.52
02.42		Goclenius	    04.47
02.47		Langrenus	    04.53

Regulus and Saturn

During the eclipse the bright star Regulus (Alpha Leonis) will be near the northern limb of the moon. In fact, just before the eclipse, an occultation of the star can be observed from the southern part of South-America and the southern Atlantic Ocean. Bright planet Saturn can be found to the southeast of the eclipsed moon.

Next lunar eclipse

This year will see a partial lunar eclipse on August 16. The next total lunar eclipse will occur on December 21, 1010. That eclipse will be visible from eastern Asia, Australia, the Pacific, the Americas and Europe.

Organization

Webpage and live webcasts are organized by


Carl Koppeschaar
 
 

Norbert Schmidt
 
 

Arnold Tukkers
 
 

Philippe Mollet
 
 

Eduard Masana (left),
Victor Gómez,
Salvador Ribas (right)

Hochschule Offenburg
 
 

Luis Manterola
 
 


FURTHER INFORMATION


February 21, 2008 total lunar eclipse:


General information:

Previous webcasts organized by Astronet: