dipper@utastro.UUCP (Debbie Byrd) (12/08/85)
If you've got a clear sky at sunset, you can see the shadow of the Earth. We'll tell you how -- right after this. December 8 The Shadow of the Earth Like everything that has sunlight shining on it, the planet Earth casts a shadow. You can see Earth's shadow without traveling into space -- but first imagine how it would look if you were in space. All the space inside our solar system is lighted by the sun. The only dark places are in the shadows of obscuring objects -- such as planets or moons. Like people sitting around a campfire, each object in the sun's family has one lighted side and one dark side -- and long shadows extend out opposite the source of light. We call Earth's lighted side its "day side." As the planet rotates, the day side continually moves around it. The trick to seeing Earth's shadow is to be standing outdoors just when the day side is moving away -- in other words, at sunset. You need a couple of other things for this observation including a cloud-free horizon and a clear view of the east. If conditions are good, you can look opposite the direction of the sunset to see a curved line of darkness moving up from the eastern horizon. You've probably seen this ascending darkness many times and imagined that it was haze or clouds. What you're really seeing, though, is the shadow of the Earth. The shadow is curved because Earth is round -- and you can see it because its deep blue color contrasts with the pink and pale blue of the twilight sky. Watch for it -- the shadow of the Earth -- after sunset some evening soon. Script by Deborah Byrd. (c) Copyright 1984, 1985 McDonald Observatory, University of Texas at Austin
ajs@hpfcla.UUCP (12/09/85)
> One of my most vivid memories of the February 26, 1979 total eclipse > of the sun was watching the shadow of the moon racing toward me over land. Yes, I had the good fortune to see the same eclipse (from Lewiston, Montana) and experienced the same thing. Lots of reading, etc., had prepared me for what the sun would look like. Of course actually SEEING it in crystal white, with red flecks, surrounding an utter black circle, was still wondrous. What was even more amazing, and totally unexpected, was the complete environment of the eclipse, of which the sun up in the sky was but a small part. 10-15 minutes before totality, the western sky looked like it might just before an hellacious thunderstorm. Then, during totality, there was a fantastic "ring of fire", the color of sunset, around the entire horizon. Very high, thin cirrus clouds glowed white with a trace of light, against a black sky, due to the low sun angle (only about 30 degrees). The shadow washes over you like an enormous, slow breaker, crushing you against the sand (or in this case, snow). If you've ever snorkeled under a BIG wave and looked up as it went by, you know the feeling. I'd go way out of my way to see another total solar eclipse, some day. Until then, if you want to see the shadow of the Earth, I recommend Maricopa Point on the South Rim of the Grand Canyon, on a clear evening at sunset, looking east-northeast across the canyon. Alan Silverstein
karn@petrus.UUCP (Phil R. Karn) (12/09/85)
One of my most vivid memories of the February 26, 1979 total eclipse of the sun was watching the shadow of the moon racing toward me over land. It was an eerie feeling; it seemed like a big black curtain was being swept by and I almost felt the instinctive urge to duck. Phil