Sunday, November 28, 1993: Eclipse Time

by Wes Stone

I had been waiting for this eclipse throughout the year. The last two total lunar eclipses were hidden from my view behind blankets of clouds bearing rain and snow. If I did not have better luck this time, I would have to wait three more years. As the night approached, it was apparent that the weather would be a problem yet again. A week in advance, forecasters were predicting a stormy Sunday night.

The day dawned cloudy, and a moderate shower darkened the early afternoon skies. It would be cloudy for the eclipse, but how cloudy? During the summer, storms often arrive in cells, small pockets of cloudiness surrounded by clear sky. Winter patterns are much less predictable, and the sky in early evening was solid gray. Occasionally, the full and as yet un-eclipsed Moon would shine through the multiple cloud layers, serving notice that there was still hope. The TV weathercasters were less optimistic, predicting freezing rain and up to three inches of snow before morning.

Thirty minutes before the beginning of the umbral eclipse, the Moon was not in sight. The next time I poked my head out, however, the Moon was there: full, shining through the clouds, with a telltale dimming on the eastern side where it met Earth's shadow. A glimpse through the telescope showed the smooth floor of the crater Grimaldi as it was swallowed by the brownish shadow. Most of the lunar features became invisible as they appeared to cross over to this surrogate dark side. As the Moon shrank to a half-lit crescent, it hid itself behind dense layers of clouds before re-appearing. A layer of high clouds kept the sky from becoming truly transparent. I saw the appearance of the great crater Tycho change as it lost its rays to the umbra. Tycho's walls became a black ring around a sunlit floor. The Straight Wall was a black pen-stroke across the surface.

I had hoped to follow the shadow's progress across Tycho, but clouds soon made telescopic viewing impossible. I trained the scope on the Orion Nebula, but the clouds cut me off as if they knew what I was doing. The Moon remained hidden. Totality approached, and the remnants of the lit portion were a vague shimmer behind a dark shroud of atmospheric moisture. Occasionally, clear patches formed elsewhere in the sky, showing how perfect the night could have been for observing. One of these patches was nearly overhead, allowing me to observe the galaxy M33. When I did turn my scope its way, the galaxy was more impressive than I had ever noticed with this small refractor. It had definition, elongation, and a peculiar misty sheen. The Andromeda Galaxy was impressive, as were its companions M32 and M110. At no other Full Moon would I enjoy even passable views of these faint and diffuse objects, but during a lunar eclipse they shone at their best.

Totality arrived with the Moon still obscured by clouds. The total eclipse would last for 48 minutes, ample time for the sky to clear. I was still anxious, as missing totality would effectively mean missing the eclipse. I had seen a partial eclipse a mere year and a half ago. Totality is when the Moon is completely within the umbra, the darkest portion of the Earth's shadow. It is then that the Moon appears not black, but blood red. From the Moon, the Earth occults the Sun, but the red portion of sunlight gets through the Earth's atmosphere and provides the Moon with some light.

About 15 minutes into totality, the Moon showed up, presenting a darkened disk with a black central area and a brighter southern edge. The other edges glowed red. The Moon vanished yet again, so I turned my attention to objects in the clear portions of the sky. I needed to gaze at M33 again. M35, a large open cluster in Gemini, was perfectly framed in my low-power eyepiece. A little over 10 degrees from the Moon sat the Crab Nebula, a faint but famous supernova remnant. The eclipsed Moon let this object show itself as a luminous blob. So, too, did the lack of fierce moonlight allow the three grand open clusters in Auriga to leave a lasting impression.

It was about this time that the clouds finally broke from around the Moon, allowing it to stand in bloody majesty between the Pleiades and the Hyades. The patch of brighter light had moved eastward along the southern edge, but something else was happening on the eastern edge. In my telescope at 79x, I saw a faint star perched just off the limb of the Moon, appearing to float above the ghostly lunar landscape. The clouds stayed away long enough for me to track the Moon as it neared the star. The tiny point of light merged with the lunar disk, and then suddenly disappeared, occulted by our eclipsed satellite.

I used the remaining minutes of totality to continue my exploration of winter deep-sky objects. M77, M78, NGC2392, and the Double Cluster all fell into view. I turned back to the Orion Nebula and saw its tendrils reach across my field, asymmetrically anchored in the central Trapezium.

The clouds had held off as long as they would. I saw the Moon again just as its southeastern edge left the umbra, and rediscovered Grimaldi hiding on the dark side. I missed the reappearance of Tycho, although I got in a couple of good views as the Moon was about 3/4 of the way out of the umbra. At the end of the eclipse the clouds were heavy and unbroken again, as if they had only grudgingly parted to allow a mortal to view the celestial spectacle above them.

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