Educator Features

Sun-Earth Day: A Spring Tradition
03.23.06
Lines on Earth showing the path of the eclipse beginning in Brazil and extending across the Atlantic Ocean, northern Africa, central Asia and ending in western Mongolia
It's an annual event. NASA celebrates Sun-Earth Day each spring so everyone can better understand how the sun, Earth and other planets in the solar system interact. Each year, SED presents a special focus on some issue pertaining to that special connection. In 2005 the emphasis was on ancient observatories. This year the theme is Eclipse: In a Different Light -- and for a good reason. March 29, 2006, presents an opportunity for everyone to view an eclipse by webcast.

Image to left: People who are not in the path of the eclipse can watch it on the Web. Credit: NASA

An eclipse takes place when one celestial body -- in this case, the sun -- is blocked from view by another celestial body. On March 29, the moon will pass between the Earth and the sun, causing a total solar eclipse.

Eclipses have fascinated humans for centuries. Early records of eclipses go back as far as China in 2134 B.C. and Greece in 762 B.C. Clay tablets found in Sumaria referred to eclipses. In more recent years, Einstein proposed testing his theory of general relativity by observing how light from distant stars follows curved paths as it passes close to the sun. This could be seen only during a total solar eclipse.

Solar eclipse
Image to right: The corona is the sun's outer atmosphere. During a total solar eclipse, we can see the sun's corona. Credit: NASA

NASA's Sun-Earth Connection and Live@Exploratorium will offer a webcast to view this remarkable natural phenomenon. When the moon moves directly between the Earth and the sun, the moon's shadow will first be seen in Brazil and extend across the Atlantic Ocean, northern Africa, and central Asia where it ends at sunset in western Mongolia. To view a total solar eclipse, however, you have to be somewhere along the narrow path of totality, where the moon's shadow falls onto the Earth's surface.

The eclipse won't be visible in North America, but thanks to technology, that won't stop anyone from seeing it this year.

Weather permitting, the Exploratorium webcast will begin in Turkey at 10 a.m. Universal Time -- 5 a.m. EST. Experts from NASA and the Exploratorium will provide commentary and instructions on what to look for. There will also be a telescope-only feed at 9:30 a.m. UT (4:30 a.m. EST). This stream is for people who want to see the eclipse without any audio accompaniment. The video is a mix of four different telescope feeds. To find out more about either broadcast, go to http://www.exploratorium.edu/eclipse/2006/index.html.

Watching the eclipse through the webcast adds an element of safety to the experience. After all, no one should view an eclipse without taking special precautions. The most popular, safe way of viewing an eclipse is with a pinhole camera, which provides a projected image of the sun onto a paper screen. Since North Americans won't be able to view the March 29 eclipse without the aid of the webcast, protecting eyes from solar intensity is not a worry this time.

NASA wants to gather resources and experiences of eclipses. If you have witnessed an eclipse, e-mail NASA with a short story of your account. Selected "E-Clips" accounts will be featured on NASA's Web site.

NASA has created a selection of eclipse-related educational materials, including a special episode of NASA CONNECT™. In "Path of Totality: Measuring Angular Size and Distance," students learn about the natural phenomena that create a total eclipse. Students also explore the history, mythology, science and mathematics that relate to these amazing events. A selection of educational resources is listed in the links below.

Related Resources
Webcast Information -- The Path of Totality and Times for Viewing the Eclipse in Different Time Zones
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2006 Sun-Earth Day Web site
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2006 Sun-Earth Day Kit With Download and/or Ordering Information
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NASA CONNECT™ Shows That Relate to Sun-Earth Day Topics
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Enjoy Our New Series of Sun-Earth Day Podcasts
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A Variety of Eclipse-Related Animations and Videos
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Eclipse Image Gallery
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Share Your Eclipse Story at E-Clips
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Local Events of Solar Importance, Listed by State
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NASA's Solar Eclipse Page Offers a Calendar of All Eclipses Until 2010
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Learn More About the Relationship Between Einstein and Eclipses
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Maggie Griffin/NASA Educational Technology Services