Image above: The sun's corona, or outer atmosphere, is visible during totality - when the sun is totally obscured by the moon's shadow. Credit: NASA TV
NASA gave people a front row seat to today's total solar eclipse, thanks to a partnership with the University of California at Berkeley and the Exploratorium. A streaming webcast brought the eclipse - visible along a path from South America to Africa to Asia - to schools and museums and computer desktops worldwide.
Highlights (28 seconds): + Windows | + Real
Multiple cameras and filters (5:22): + Windows | + Real
The eclipse coverage was part of Sun-Earth Day, celebrated every year to help everyone better understand how our sun interacts with the Earth and other planets in the solar system. This year's theme, "Eclipse: In a Different Light" shows how eclipses have inspired people to observe and understand the Sun-Earth-Moon system.
Image above: Left: The sun creates a "diamond ring" effect as it emerges after totality. Right: Prominences which are dense clouds of material suspended above the surface of the Sun by loops of magnetic field are visible at the edge of the moon's shadow. Credit: NASA TV
NASA and Libyan scientists also conducted joint scientific activities in Libya to observe and study the event.
+ Gallery: The View From Libya
For astronaut Jeff Williams, set to launch to the International Space Station tonight, the eclipse is "an example of what has fascinated people throughout history and has inspired people for discovery and exploration, to understand why things like that happen."
A total solar eclipse is very rare because all parts of this puzzle must line up correctly in order for it to occur. The moon must be in its new phase for a solar eclipse to take place. The moon's shadow has two parts-a central region called the umbra and an outer region called the penumbra. The part of the moon's shadow which passes over you determines what kind of eclipse you will see.
Image above: Left: The moon's shadow falls on Earth, as seen from the International Space Station 230 miles above. Expedition 13, the next space station crew, launches from Kazakhstan tonight
(+ Space Station Section). Photo Credit: NASA.
+ More images from ISS
+ Feature story about the eclipse from ISS
This eclipse's path begins in Brazil and extends across the Atlantic Ocean, Northern Africa, and Central Asia where it ends at sunset in Northern Mongolia. A partial eclipse path, within the much broader path of the moon's penumbral shadow, includes the northern two thirds of Africa, Europe, and Central Asia.
In a total eclipse like this one, the entire central portion of the Sun is blocked out. The sky darkens as though it is nighttime and - for the only time - you can see the Sun's corona, or outer atmosphere. Total solar eclipses are of special interest to astronomers because it's the only time they can study the corona. Scientists still don't understand why the corona is so hot. Its temperature is 1 to 2 million degrees Fahrenheit while the Sun's bright surface is only 10,000° F. Careful measurements and experiments made during a total eclipse can help to unravel this enigma.
Image above: A merger of a space image from the NASA/ESA SOHO spacecraft and an image taken from Kastellorizo, Greece, by the Williams College Eclipse Expedition (from Williamstown, Massachusetts). Though SOHO can observe the solar corona on the face of the Sun and can observe the outer part of the solar corona, the "doughnut" between those images is not visible from Earth except during total solar eclipses. The Williams expedition is supported by grants from NSF, NASA, and National Geographic. The reddish image from SOHO shows the Sun's disk at temperatures around 60,000 - 80,000 K. The red image from SOHO shows gas at the millions of degrees typical of the sun's corona. Merging the eclipse image with the space image from SOHO allows astronomers to trace features in the corona from their bases on the Sun's surface up until the gas escapes into interplanetary space; some of this gas winds up hitting our Earth's upper atmosphere. The orientation of the eclipse image versus SOHO is an approximation. Credits: Jay Pasachoff, Bryce Babcock, Steven Souza, and Jesse Levitt, and the Williams College Eclipse Expedition.
This year's eclipse is also special because the total phase lasts over 4 minutes at the center of the path. This is quite long for a total solar eclipse since most last just a minute or two. The next total eclipse,on August 1, 2008, will be seen in northern Canada, Greenland, Siberia, Mongolia and northern China. It will last about 2 minutes. The next total eclipse visible from the United States won't happen until August 21, 2017.