One of the world's largest general astronomical groups will meet in Casper the week before the total eclipse of the sun next year, its spokesman said Monday.

"At the pace we're going at right now, I would be surprised if we were any less than 400 to 500 people," said Carroll Iorg, the immediate past president of the Astronomical League.

The 60-year-old League is a worldwide federation of more than 280 general astronomical societies. The Astronomical League has never conducted its national convention, ASTROCON, in conjunction with a total solar eclipse, Iorg said.

The scientific conference is among the events up to and including the total solar eclipse at 11:42 a.m., Monday, Aug. 21, 2017, during the local celebration dubbed EclipseFest. Local governments, the Casper Area Convention and Visitors Bureau, and other groups are coordinating the logistics of EclipseFest.

Iorg has been to a lot of total solar eclipses in remote areas, and they attract thousands of scientists and spectators, he said.

"It's taken a while for the general public to really wrap themselves around the fact that that's what happens," Iorg said. "When people go to these out-of-the-way places around the world, oh, yeah, it's a very big deal. And a lot of people show up for it."

Casper is on the center line of the total solar eclipse that will reach the mainland United States at 10:16 a.m. PDT that day. The shadow will cross Salem, Ore., Boise, Idaho, Grand Island, Neb., Kansas City, Mo., Nashville, Tenn., and move into the Atlantic Ocean near Charleston, S.C., at 2:49 p.m. EDT.

The Astronomical League had considered other places along that path, but the totality at Casper, coupled with central Wyoming's high altitude and high probability of clear weather cinched its decision, he said.

ASTROCON will feature major speakers on eclipses and general astronomy during its Aug. 16-19 convention at the Parkway Plaza, Iorg said.

The top speaker will be Fred Espenak, the National Aeronautics and Space Administration's expert on eclipses, Iorg said.

Espenak is a scientist emeritus at Goddard Space Flight Center and maintains NASA's official eclipse web site and has a personal website on eclipse photography.