Total Solar Eclipse Notes

March 29, Side Turkey


I will be the host for a webcast of the Total Solar Eclipse by the Exploratorium in collaboration with NASA. Isabel Hawkins of will be my Co-host from NASA's the Sun-Earth Connection Education Forum.

Before we departed for the Eclipse site we did several rehearsals at the Exploratorium Webcast theater. Then it was time for the real thing!

Here are my thoughts day by day as we prepare for the eclipse:

March 25, 2006, Rendezvous

An Exploratorium crew flew almost half way around the world to rendezvous with a total solar eclipse on the coast of the Mediterranean Sea in Side, Turkey. We traveled by jet aircraft moving at more than 700 km/hr (500 mph) just a bit slower than the speed of sound. With one long layover our trip took 24 hours. During that time, the surface of the earth had rotated once around on its axis, the moon had raced 1/30 the of the way around in its tilted monthly orbit, and the earth had completed 1/365 the of its orbit around the sun. All of these motions will come together and result in us standing in the shadow of the moon on March 29, 2006 at 1:54:59 PM for 4 minutes.

March 26, Eclipse by car headlight

The last leg of our trip was by bus, late at night. As we drove along the coast a wispy miasma of fog danced across the road. Oncoming car headlights illuminated the fog from behind while bare trees in the median of the highway cast three dimensional shadows through the mist. We drove through these shadows. It was an awe inspiring sight.

Imagine a young solar system still full of dust with a planet like the earth and its moon. Sunlight scatters off the dust-laced vacuum of this system making space glow with light, (in our present solar system the nearly empty vacuum of space scatters no light and is invisible.) In this hypothetical dusty space the dark umbral shadow of the moon would be visible as a three dimensional cone with its base at the moon tapering to a narrow point at the distance of the moon from the earth. From any point within this cone a viewer would not see any part of the sun. Looking more carefully, a viewer would see a dimmer gray frustum of a cone spreading out from its narrow end near the moon and its wide end pointing away from the sun. Within the gray penumbral region a viewer would see only a part of the sun. They would see a partial solar eclipse.

A large fraction of the earth will enter the penumbral eclipse zone where viewers will see a partial solar eclipse, while a narrow band of the earth, a mere 100 miles wide and a few thousand miles long will encounter the umbral shadow. People inside this shadow zone will see the amazing spectacle of a total solar eclipse.

March 27, The Amphitheater

In Side Turkey will will do our webcast from the stage of a two-thousand-year-old Greco-Roman amphitheater. The theater originally seated 15,000 people and has been restored so that it is still in use today for concerts and eclipse webcasts.

The Exploratorium is doing an experiment during this webcast, we are broadcasting the eclipse program in a massive multiplayer game on the web named Second Life. One of the great builders in that game, Aimee Weber, recreated a 3-D model of the amphitheater that is amazingly close to the original in its appearance. Our webcast will be played on a giant screen in this virtual amphitheater.

Next to the amphitheater, Aimee built a modern Planetarium. Inside a huge steel sphere, inside a glass walled building, Aimee created a 3-D model of the Sun, the Earth and the moon showing how the moon will move and the earth will rotate during the eclipse to create a shadow that sweeps across the face of the earth producing the path of totality. The planetarium also contains exhibits that would be difficult to build in the real world, a scale model of the earth and the moon, with a 1 meter diameter earth, and a 25 cm diameter moon 30 meters apart, a model showing the conical umbral and penumbral shadows, and a model showing the five degree inclination of the moon's orbit. It will be interesting to hear how people react to our experiment in creating new ways to learn.




Scientific Explorations with Paul Doherty

© 2006

25 March 2006