Africa 2001
Zambia: Eclipse!
|
Zambia
Shauna Kelly Designed for Internet Explorer, v.5.0 or higher and screen resolution of 800 x 600. All images in this website are copyright Shauna Kelly. No use without written permission is authorized. But links to any of these pages is appreciated. |
For purists, astronomers, amateur enthusiasts and serious eclipse watchers, the interesting part of an eclipse is totality. But I found myself as interested in the partial phases before and after the eclipse as the few minutes of totality. It is not safe to look at the sun except during totality. Nor can you take a photo of the sun without appropriate protection for you and your camera lens. Everyone at the camp had eclipse glasses that make it safe to view the sun, and cameras, binoculars and telescopes were fitted with solar filters. The photo below, and those that follow, were taken using a solar filter. Before I left home, I had constructed the filter of Baader Solar Filter material, cardboard and sticky-tape so it fitted snugly on the front of the camera lens. It blocks out almost all the light, which enables you to look at the sun, and to photograph it. This is why the sky appears black on a day of a brilliant, cloudless, blue sky. At 1.40pm local time, the sun looked like the sun looks any old day.
A moment later, looking through eclipse glasses, I could see a nibble, a tiny nibble on the lower left edge of the sun. The moon had grazed the edge of the sun. All I could think of was: "it's really going to happen", as if there had been some doubt in the matter!
Quite rapidly, the nibble grew. Yet it took about an hour and a half from that first nibble until the sun was entirely engulfed by the moon. With our eclipse glasses, we could see three or four sunspots on the sun.
Suddenly, we could see the corona around the sun. It's always there, but we can't see it because of the glare of the sun. You can only see the sun's corona during a total eclipse.
During totality, people don't need eclipse glasses and camera lenses don't need solar filters. So these photos of the sun during totality are taken without the solar filter. Here, the sky looks black because it was black! It was light enough to see, and recognize, the people standing beside me. But it was dark enough that I could not distinguish the controls on my camera. With longer and longer exposure times, it is possible to capture more of the corona at the expense of losing detail around the sun. The following pictures were taken with shutter speeds of about 4 seconds and 8 seconds.
Totality lasted about 3½ minutes. Before the eclipse, experienced eclipse watchers said "it will be the shortest 3½ minutes of your life." They were right. So much happens, so extraordinary is the scene, that it all happens very quickly. As suddenly as totality came, it went. And it went with a remarkable display. It's called the diamond ring effect. It is seen at both ends of totality: just before the moon completely hides the sun, and just as the sun begins to emerge from behind the moon. This photo was taken just as totality ended. Sunlight was beginning to return. The edge of the moon isn't smooth: it has mountains and valleys. So as the sun slips away from the moon, a tiny bit of light will slide through a valley on the moon, creating the diamond ring. The little sparkle of light near 9 o'clock is a prominence. To the naked eye it looked bright red. Prominences are huge eruptions of gas from the surface of the sun. That tiny speck is big enough to engulf the earth.
The Diamond Ring lasts only a few seconds. In moments, the sun began to return. It was another hour and half before the sun had completely cleared the moon. By then it was nearly 4.30pm, so the heat of the day didn't return. That night was the coldest of my whole holiday. There was ice on the tents next morning. I haven't been able to find out if this was a coincidence, or was an effect of the eclipse.
|
