Astroverein-Halle.de: The Total Lunar Eclipse of November 8/9, 2003


	The Total Lunar Eclipse of November 8/9, 2003
	Red Moon in cloudless skies

An account by Marc Weihrauch, Halle (Saale) / Germany All times given in CET=UT+1 23.15: For hours the skies have been clear; hopefully they will stay so! The moon is shining full and bright. Its glaring light is dominating the heavens and allows only the brightest stars to be seen. In fact it is bright enough to read a book! But now Luna reaches the penumbral shadow of the Earth - the eclipse begins. However, the entrance into the penumbra is not noticeable. A while ago I have set up the 8-inch Schmidt-Cassegrain telescope that Prof. Grau of the Department of Physics at the University of Halle (Saale) kindly lent me. I have installed an old SLR-camera to shoot a couple of photos during the eclipse using ISO200 color slide film.
23.56: According to estimates by Fred Espenak the penumbral eclipse should become visible around midnight. Indeed I can perceive a distinct change now. The moon is not as glaringly bright as it was before. Especially striking is the difference in brightness between two opposite parts of the lunar limb: The vicinity around Sinus Roris with the adjacent Mare Imbrium and Oceanus Procellarum ("upper left") appears noticeably darkened as compared to the Maria Crisium, Tranquilitatis and Fecunditatis ("lower right"). Why, actually, does the old fairy tale that one cannot observe a penumbral eclipse still last?
00.32: Now the moon is gliding into the dark umbral shadow of the Earth. Until now one had to watch attentively to notice the darkening. From now on it strikes everybody that something is going on. It seems as if a larger and larger piece of the moon was bitten out.
	00.46: Noone is eating the moon. The missing piece is simply darkened by the shadow of the Earth. With progressing eclipse the blinding by the uneclipsed part of Luna is subsiding. Now it is possible to see the darkened part feebly again. A short-exposed photo shows the uneclipsed part only. At a longer exposure the dark part can be seen, but then the uneclipsed side is totally over-exposed.
01.00: I place myself behind the planetarium, so that its roof covers exactly the uneclipsed part of the moon. Without the glare from the bright side I cannot only see dark side more clearly but even recognize its red color. The hue reminds me of smoldering charcoal.
01.12: The red of the dark side can now be seen without such tricks.
01.23: With the unaided eye I can recognize structures on the eclipsed part again: The maria, the great dark areas, are clearly visible.
	01.37: The more the eclipse progresses, the more the moonlight loses strength. Who said during there were no changes in the skies and in the ambient light levels during a lunar eclipse?! The moonlight shadows are almost gone, and the sky has turned much darker. More and more stars come out. The pleiades and hyades in Taurus can now easily be seen - two hours ago they could only be guessed.
01.45: So little moon left, and still so much time! Only a thin stripe remains of the moon. It is hard to believe that it is still 20 minutes to totality. But the partial eclipse is especially long this time because the moon moves along the edge of the shadow of the Earth and not right across. It has almost reached its "pseudo-Mars-stadium": The red color of the eclipsed part reminds of the Red Planet, the maria remind of the dark areas on the surface of Mars and the uneclipsed part of the polar cap. Ten minutes before totality a colleague from the planetarium appears, only to ask some organizational question regarding the usual public lectures. She is the third person this night to disturb in such a way. I would happily answer eclipse-related questions even now, but such trifles will have to wait. (Being disturbed just before totality appears to be my fate - it was a drunk in Zambia 2001.) As if that was not enough some bored dude starts playing some rather bad music. There is but a very limited choice of music suitable for the sublime occasion of an eclipse, and the latest radio hits croaking from a mobile phone definitely do not belong to it. If I ever join a public eclipse observation again I will spread a number of warning signs all around myself, saying "Eclipse in Progress - Beware of Umbraphile!"
	02.06: Totality. The moon is completely inside the umbra now and does not receive any direct sunlight anymore. Only the atmosphere of Earth directs a part of the sunlight into the shadow like a giant lens - without this effect the moon would be completely invisible. At the same time the atmosphere filters the light, preferably it lets the long-wave part pass. Long-wave light appears red to us - hence the red color! Of course the outskirts of the umbra are brighter than its central part. Because the moon moves along the inner edge of the shadow it has a bright rim all the time. Some guests get confused by that and believes the eclipse was not total at all. But the eclipse should look exactly like that! Everybody expected that bright rim. Actually the eclipse is rather bright. The moon appears copper-red. On one side it is darker, the red much deeper. In contrast, on the other side ("lower left") it is rather bright. It looks gray there, almost with a yellowish touch. All over the moon the remaining light is sufficient to recognize structures. The maria, the great dark areas making up the "face" of the moon, are cleary visible even at mid-eclipse. On the Danjon-scale reaching from 0 (very dark eclipse, moon almost invisible) to 4 I estimate the Red Moon of this night a 3. In the meantime it has become almost as dark as a new-moon night. Our moonlight shadows have vanished completely, the stars are clearly visible. Not only these: Two or three times we see a meteor dash past the eclipsed moon. By the way the photo shows a starlet above the northern lunar limb, that was eclipsed itself later.
	02.18: Mid-eclipse. Luna will not penetrate any deeper into the shadow of the Earth. The tiny star has drawn much nearer to the lunar limb. No, wrong! Of course it is the moon itself that has moved on in its orbit and altered its position relative to the star.
	02.30: After only 24 minutes totality is approaching its end. For a lunar eclipse this is rather short. The bright rim has moved a bit to the "upper left" in the meantime and is becoming increasingly brighter. Soon a white stripe appears - this part of the moon has already left the umbra. By the way, this stripe is much brighter than the rim that was visible during totality. The star from a while ago is not visible anymore. It has been obscured by the totally eclipsed moon!
	03.00: The moon is receding more and more from the umbra. Most guests and even the members of our society set out. I take down the telescope but stay at the observation site. That's a matter of honor! The photo on the left was taken a little earlier, just a few minutes after 2.30 a.m.
04.04: Luna has completely left the umbra and is only inside the feeble penumbra of Earth. The moonlight is almost as bright as in any full-moon night again, the stars have faded, and the eclipse is over even for me. I hammer a short report of success to the eclipse-mailinglist into the keyboard, then start home - looking forward to the next time.