The center's Dome Theater was geared for NASA's simulcast and pre-eclipse program that was to run from noon to 4 p.m.
In addition to the simulcast, the center offered two alternative means of seeing the eclipse: special glasses, of which 1,000 had been distributed, and instruction on how to make a pin-hole that acted like a lens to project a small image of the eclipse onto any handy flat surface.
Joe Yachanin, a spokesman for the center, said it was a sell-out crowd which is unusual for a weekday.
The throng included U.S. Sen. Rob Portman (R-Ohio), who arrived just as the eclipse was beginning, watching from the lawn on top of the garage for about 35 minutes.
Some of the NASA simulcast originated from Jefferson City, Missouri, that state's capital and a place thought to give one of the best views of the eclipse. The video team there was joined by Dante Centuori, the science center's scientist-in-residence.
Jeff City, as natives call it, was also chosen because Janet Kavandi, NASA Glenn's director is from that state.
The Cleveland Metropolitan School District sent its mobile Fab Lab to give visitors a chance to use advance technology including 3D printing and a computer-guided laser-cutting machine than can make intricate form out of a single piece of wood as thick as a half inch, according to the lab's Sarah Wallace.
One project that people tried Thursday was to cut out frames that were to hold solar-filter film so people could safely view the eclipse.
But she said the film has been sold out for weeks across the nation because of the eclipse.
Robyn Kaltenbach, the center's public-programs manager, said the eclipse was great for the center because "we rarely have the opportunity to do something of this magnitude."
She said it was also an important teaching moment for the center "because most of the guests here today were not even alive for the last major eclipse," which was in 1979.
Among the guests were Kris Hill of North Ridgeville and her sons Caden, Liam and Paxton.
She said they hoped for different perspectives because they would see the eclipse in Cleveland and "Grandpa in Greenville South Caroline will get the total view there and might send along some video."
By 3:15 when the final third of the eclipse was still visible, most of the crowd had already gone.
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