Eclipsed Eclipse and other Astronomical Frustrations

Rec 03-mar-2007 23:30

Once again I was unlucky with astronomical phenomena. After several cloudless days and nights, tonight's total lunar eclipse was eclipsed by uncharacteristically thick clouds (but with no rain). The geometry of the event seemed reasonsably good and it was during moonrise, in the early hours of the night here, in the east horizon, making it ideal to be seen from the Boa Viagem beach shoreline.

Lunar eclipses are trivially easy to see. There's no need for binoculars or telescopes: the event is as obvious as the full moon itself. They're pretty and they're not scary. They can be a bit frustrating to photograph if you don't have the proper training in astrophotography.

May people just starting in astronomy seem to think that the full moon is the best time to watch it through binoculars or telescopes. It isn't, in fact: under any modest magnification, the Moon's glare will be too strong and the sun will be illuminating from above, so there will be too few shadows to provide contrast. It will look washed out and rather featureless. Try watching it near first or last quarter: the sun at an angle will make shadows that will provide excellent contrast; and it will not be too bright, so it won't hurt your eyes as much. You will see much finer features. The full moon is good for watching eclipses just because lunar eclipses only happen during full moon, but only about two full moons per year will be an eclipse.

Anyway, I had to content myself with simulating the event using my Stellarium 0.8.2 setup. But despite Stellarium's attempt at photorealism, it's not anywhere as pretty as the real thing. You can also simulate it with Celestia, although it looks nicer from space -- click here if you already have Celestia installed.

I've seen a few total lunar eclipses and one almost-total solar eclipse. But I haven't seen a total solar eclipse just yet. Everyone I know that has seen one says it's one of the most beautiful phenomena there are and that no picture does justice about how impressive it is. For the supertitious, it can be pretty scary -- for almost two minutes, the day turns to night (with stars and everything) and the sun's corona make it look like it's very angry.

Clouds near the horizon was also the reason that I missed Comet McNaught in January. Unlike eclipses, comets are very hard to see from urban centers because of light pollution.

There will be another total lunar eclipse on August 28, but Stellarium says the moon will have already set, so it won't be visible here.

On the other hand, the next one on Feb 21, 2008 looks very promising -- Recife is near the middle of the visibility range, so the moon will be near the zenith. If the weather cooperates, it will be almost a birthday gift.
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