See the eclipse on the Web

Ninety years ago, a total solar eclipse provided the first solid confirmation that Albert Einstein was right about a little thing called general relativity. Today, eclipses may not be as much of a draw for astronomers as they were in the days before sun-observing satellites, but they still serve an important scientific purpose. Looking beyond the science, there's something elemental, even spiritual, about experiencing totality.

Nothing can take the place of seeing today's Asian eclipse in person, but if you can't be in Shanghai or Bhopal, scientists are still willing to bring you a taste of totality via the Internet. Here's a mini-guide to the Webcams, plus some pointers to the science behind the spectacle:

• Live-Eclipse.org: The Japan-based "Live! Universe" team has been doing eclipse Webcasts for years, and it sounds as if they have a great show in store this year. Viewing positions have been set up in the Chinese city of Jiaxing, southwest of Shanghai, at two locations in Japan (Nakanoshima and Amami City) and on Marakei Atoll in the Pacific. The broadcast, streamed using Flash and Silverlight, is due to be on the Web from 8 p.m. ET to midnight.
• University of North Dakota SEMS: Scientists from North Dakota are set up for observations in Wuhan, west of Shanghai on China's Yangtze River. Their servers will be dishing up video for Windows Media Player as well as for the VLC video plug-in. Coverage begins at 8:14 p.m. ET, with maximum totality due at 9:26 p.m. There's also a blog and a Java-based chat room.
• Saros Group: This expedition has also set up for observations in Wuhan, but there's not much advance information about how the Webcast will play out. You can assume that the choicest time frame will be similar to the University of North Dakota's sweet spot, in the 8:45 to 10 p.m. ET time frame.
• Taiwan Webcast Group: Observers have scheduled their Webcast from China from 8:20 p.m. to 11 p.m. ET. You need to run the Windows Media Player browser plug-in to see the show.
• Chinese Astronomical Society: A network of observation stations have been set up in the Yangtze River region, and the project's organizers will select the best views for airing on the Webcast. Seeing the video requires a browser plug-in, and it's hard to predict in advance how the system will perform. Peak viewing should be in the 8:45 to 10 p.m. ET time frame.
• Eclipse-TV.com: Here's something different .... Germany-based AstroNative Technologies and Eclipse-City offer an HD video stream of the eclipse from Yangshan Island, south of Shanghai. The coverage begins with the partial phase at 8:24 p.m. ET, goes all the way through the total phase (starting at 9:37 p.m. ET) and ends when the sun's disk is fully uncovered again at 11:03 p.m. ET. The catch is that you have to buy a virtual "ticket" to watch, at a cost of 9.95 euros (roughly $14). Check the International Year of Astronomy's Web site for free information.

After the event, you can expect at least some of these Web sites to offer archived clips of eclipse highlights. If any video clips come to our attention, we'll link to them here, and you can always check our main story about the event as well. It's also a safe bet that SpaceWeather.com will have plenty of eclipse pics on display.

As for the science behind eclipse observations, Williams College astronomer Jay Pasachoff has long contended that sun-observing spacecraft can never totally take the place of total-eclipse observations on Earth. He argued his case in detail last month in the journal Nature.

"Instruments on spacecraft are carefully made for specific purposes, and are locked into their configurations many years in advance of their use," he wrote. "In contrast, eclipse expeditions have the flexibility to use the latest equipment and to take advantage of new theoretical ideas to frame observations."

Today Pasachoff and his team have set up their equipment on a mountain outside Hangzhou, China, to focus on the detailed, close-in structure of the corona - the sun's outer atmosphere, which is visible from Earth only during a total eclipse. Studies like Pasachoff's could shed light (so to speak) on the reasons why the corona is so much hotter than the sun's surface.

Pasachoff has been blogging about his expedition at The New York Times' TierneyLab blog, and he reports that "the weather continues to be a worry" at his observation site.

Will Pasachoff's scientific expedition end in a "wow!" or a washout? Will all these Webcam spread across China, Japan and the Pacific see anything at all? Stay tuned ... and don't be afraid to hop from one Web site to another.

Update for 8:45 p.m. ET: So far the performance has been disappointing, as far as I can tell. The sites listed above either are not yet offering video, or are not accessible, or are in pay-per-view mode. We're keeping our eyes out for other sources of eclipse video.

Update for 8:48 p.m. ET: It looks as if the streams are operating at Live-Eclipse.org, but it also looks pretty cloudy out there.

Update for 8:54 p.m. ET: Totality in India! We'll have video posted within the hour.

Update for 9 p.m. ET:Live Indian coverage here.

Update for 9:15 p.m. ET: Live coverage via msnbc.com. Prospects uncertain. (Link removed because video is no longer streaming.)

Update for 9:58 p.m. ET:Here's the video showing the total eclipse as seen a little more than an hour ago in India.

Update for 10:27 p.m. ET:"We saw it!" Williams College's Jay Pasachoff says. But it sounds as if it was a close thing. I have to say the absolute best streaming-video coverage was on NDTV's Web site, which I hadn't thought to include in my original roundup. That's a good lesson for the next total eclipse, which will be visible from the South Pacific and parts of Chile and Argentina on July 11, 2010.

More on eclipses:

• Eight memorable solar eclipses
• What causes a solar eclipse?
• Test your knowledge of eclipse lore
• Greatest hits for eclipse fans

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