# Presentation: 573879

## Total Eclipse of the Sun

*2008 August 01 *

- Fred Espenak
*NASA’s Goddard Space Flight Center*

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## Solar Eclipse Geometry 4

**Earth**

*New*
*Moon*

- Earth and Moon: Solar Eclipse Path

- Path of Totality

**Moon**

- During a total solar eclipse
-      the Moon’s two shadows sweep across Earth.

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## Partial Phases of a Total Solar Eclipse

- Every total eclipse begins with a series of partial phases which may last an hour or more. However, the total phase or “totality” never lasts more than 7.5 minutes.
- This time series photo shows an entire total solar eclipse, from start to finish over a period of over two hours.

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## Eclipse Shadows

- Astronomy Picture of the Day - August 13, 1999

*Credit:  E. Israel *

- 	When sunlight passes through gaps between leaves of a tree, the shadows on the ground show little images of the eclipse happening in the sky above. This is the same principle as the pinhole camera.

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**Notes:**
Near the shadow of the moon under a shady tree, dozens of images of a 1994 solar eclipse in progress are visible in this striking picture from the campus of Northwestern University in Evanston, Illinois. What creates the multiple images? Any small gap between leaves can act like a pin-hole camera, projecting a discernible image of the crescent sun onto the shaded sidewalk below. This tree's height and multitude of leaves combine dramatically to produce the large size and number of images. On August 11, many throughout Europe and Asia had the chance to enjoy similar views of the last total solar eclipse of the millennium as the moon's shadow raced across densely populated regions of the globe. 
(APOD: August 13, 1999 - Eclipse In The Shade )

## Eerie Twilight During a Total Solar Eclipse

- During “totality” the landscape is bathed in an eerie twilight. Bright stars and planets are visible.

- Astronomy Picture of the Day - 2003 January 08

*Credit: Olivier Staiger*

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**Notes:**
Sometimes, during a total eclipse of the Sun, a strange shadow of darkness can be seen stretching off into the distance. Called a shadow cone, they are visible because the Earth's atmosphere is not completely transparent, scattering sunlight and hence appearing blue during the day. Shadow cones are particularly dramatic for eclipses near the horizon, as geometry creates a long corridor of sun-blocked air. Visible above is a shadow cone caught during a total solar eclipse visible last month from South Australia. The eclipsed Sun itself still appears bright because of light from the surrounding corona. The digital camera on the left is zoomed in to show a better image of the actual eclipse. 
(APOD: 2003 January 6 - Shadow Cone of a Total Solar Eclipse )

## “Diamond Ring” Effect Before Totality Begins

- 	In the last seconds before totality begins, the remaining bit of Sun resembles a dazzling jewel as the ring-like corona appears.

- Astronomy Picture of the Day - June 21, 2001

*Credit: Fred Espenak*

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**Notes:**
Today, earthbound skygazers can celebrate a solstice, a new Moon, the closest approach of planet Mars since 1988 ... oh yes, and a total eclipse of the Sun, the first total solar eclipse of the third millennium. Of course for some, today's most spectacular celestial views will be of the eclipsed Sun from along the path of totality as the new Moon's shadow tracks across southern Africa and Madagascar. This picture from the August 1999 total solar eclipse captures the shimmering solar corona just as that eclipse's total phase ended, as seen from eastern Turkey. The first rays of bright sunlight shinning through edge-on lunar mountains and valleys create the fleeting appearance of glistening diamonds set in a ring around the Moon's silhouette. Do you want to see today's solar eclipse? Eclipse expeditions are offering live webcasts. 
(APOD: 2001 June 21 - Diamond Ring in the Sun )

## Glorious Solar Corona

- 	The sun’s glorious corona is composed of hot, rarified plasma with a temperature of 1 to 2 million degrees Centigrade. It is only visible during a total eclipse when the Moon hides the Sun’s brilliant disk.

- Astronomy Picture of the Day - Sept. 15, 1999

*Credit: Fred Espenak*

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**Notes:**
Most photographs don't adequately portray the magnificence of the Sun's corona. Seeing the corona first-hand during a total solar eclipse is best. The human eye can adapt to see features and extent that photographic film usually cannot. Welcome, however, to the digital age. The above picture is a combination of twenty-two photographs that were digitally processed to highlight faint features. The outer pictures of the Sun's corona were digitally altered to enhance dim, outlying waves and filaments. The inner pictures of the usually dark Moon were enhanced to bring out its faint glow from doubly reflected sunlight. Shadow seekers need not fret, though, since as yet there is no way that digital image processing can mimic the fun involved in experiencing a total solar eclipse. 
(APOD: September 15, 1999 - The Big Corona )

## Partial Solar Eclipse

- 	Partial eclipses are visible over a much larger part of Earth than total eclipses.  So they are seen by many more people.

- Partial Eclipse of Oct. 14, 2004 (Hawaii)

*Credit: Fred Espenak*

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## Annular Solar Eclipse

- Annular Solar Eclipse of May 10, 1994  (Toledo, Ohio)

- 	The solar corona is NOT visible during an annular eclipse. The remaining ring of sunlight hides the corona in its glare.

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**Notes:**
Total Solar Eclipse showing the corona and a few prominences off the limb (in red). When the moon blocks the light from the bright solar photosphere, we can see the much dimmer, more subtle evidence of the corona.

## Frequency of Solar Eclipse Types

- Fred Espenak, NASA’s GSFC

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## Total Solar Eclipse of August 01, 2008

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## Total Solar Eclipse – 2008 Aug 01

- Canada

- Greenland

- Russia

- Mongolia

- China

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## Total Solar Eclipse – 2008 Aug 01

- Nunavut

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## Total Solar Eclipse – 2008 Aug 01

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## Total Solar Eclipse – 2008 Aug 01

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## Total Solar Eclipse – 2008 Aug 01

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## Total Solar Eclipse – 2008 Aug 01

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## Total Solar Eclipse – 2008 Aug 01

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## NASA Solar Eclipse Bulletins

- Bulletin Prepared for Major Solar Eclipses
- All Total & Some Annular
- IAU Working Group For Eclipses
- Published 12-24 months before eclipse
- Hard Copy Available
- Contact: fred.espenak@nasa.gov
- Electronic Version on Web
- eclipse.gsfc.nasa.gov/SEpubs/bulletin.html

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