Saturday, August 1, 2009

The Eclipse As Viewed from Enewetak

by Beverly Lynn-Wilson
Member of the Friends of the Institute for Astronomy

The diamond ring flashed, and in an instant the Moon covered the Sun entirely and extinguished the light. After waiting for well over an hour for an imperceptibly slow moving Moon to eat away the Sun, darkness came so quickly that my brain barely had time to register what I had seen: tiny blips of light called Bailey’s Beads forming a very narrow band encircling the Sun, and then on the right side of the Sun, near the top, a last handful of bright light glowing like a diamond.

The diamond ring effect, also visible as the Sun returns (photo by Dr. Isabelle Scholl).

Darkness descended at 3:28 p.m. The temperature dropped. For five minutes and 40 seconds, it was not daytime, but neither did it look entirely like night. A yellow-white Venus shimmered low in the western sky and a few stars appeared, much as you see after sunset as twilight deepens, but during totality the sky was not quite the right shade of blue. This sky had more royal mixed in with the indigo, making it a little brighter. Under the blue, along the western horizon, the sky was lighter, an orangey-yellow tone. The ocean I was looking over, on the other hand, changed from royal blue to the indigo of the usual twilight, as if somehow the darkening of the Sun had turned the world upside down.

The corona visible during totality.

In contrast to the soft colors and the sharp shadows around me, the Sun looked starkly black with the bright silvery white lion’s mane of the corona now visible. The body of the Sun is so bright that you can see the corona, the Sun’s atmosphere, only during an eclipse. These are the photos of eclipses you typically see, but they don’t begin to capture the dramatic contrast with your surroundings or the shimmer and dance of the corona’s lines.

As suddenly as totality began, a tiny globule of Sun reappeared, as if someone had flipped on a switch, and the light returned. During an eclipse there is almost no perceptible dimming or lightening. As long as the minutest particle of the Sun remains visible, it’s light. When the Moon covers the Sun, it’s dark.

The crescent Sun, as it looks before and after totality.

The globule grew to a thin crescent and then a fat crescent, looking like phases of the Moon. In an hour and 20 minutes the entire Sun was back. This was the first total eclipse I have witnessed, after two failed attempts due to bad weather. I’m hooked!

Stay tuned for further adventures of the UH Institute for Astronomy eclipse team, whose research was funded by NASA and the National Science Foundation.