CARBONDALE, Ill. – It won’t be just another mid-summer day in this southern Illinois college community Monday at 1:20 p.m. CDT.

That’s when the moon is expected to totally block the sun for 2 minutes and 40 seconds, longer than any other time during the epic journey of the solar eclipse diagonally across the country from Oregon to South Carolina.

Grant City State Park just south of Carbondale, a city of 25,000, is the solar eclipse crossroads of the 70-mile wide path of totality. Public safety officials are bracing for 200,000 or more people for the astronomical opportunity of a lifetime.

Several million people live within a day’s drive of Carbondale, which could create massive traffic jams by visitors and eclipse chasers. Southern Illinois University has arranged to park cars on the campus and open its football stadium as a viewing site.

Sky gazers positioned at the crossroads of the total eclipse will first notice the moon’s shadow speeding at 1,600 miles across the land shortly before noon.

In the seconds before total darkness, astronomers said, they will see thin bands of light and shadow. Once the moon covers the sun, they will observe the outer atmosphere of the sun called the corona. It is an expanse of super-hot gas held in place by the sun’s magnetic field.

Mike Kentrianakis, head of the American Astronomical Society’s Solar Eclipse Task Force, reports the corona is usually invisible because the sun is so bright. Seeing it during an eclipse, he added, “boggles my mind. It’s always there, but you can only see it during totality.”

Experts say several things can happen during the total eclipse. The temperature drops, animals think it is night, dogs act strange, birds stop signing, crickets stop chippering, bats fly about.

The buildup to the event is also a time for free market capitalism to flourish.

Hotels and homes renting rooms in southern Illinois have been sold out for days. A four-bedroom home in Salem, Illinois, 70 miles north of the crossroads viewing area, offered sleeping quarters for $1,200 a night per person between Sunday and Tuesday.

Mistie Urdaneta, who owns the home, said she made the offer at the urging of a friend, noting accommodations, some at $2,000 a night, were booked solid more than 100 miles away in St. Louis.

She described the eclipse a way “to make some quick money.”

The closer you get to the crossroads, the steeper the prices. One listing in the path of totality offered a home with six beds for $5,600 a night – and the bonus of eclipse viewing glasses for each guest.

No small gift when you consider Wal-Mart, Kmart, Lowe’s and other stores selling the glasses sold out of them weeks ago.

The Business and Professional Women’s Club in nearby Mount Vernon sold the eclipse glasses as a fundraiser for $3 each. Proceeds went to the group’s community service projects and education scholarships.

“We decided way back in May to sell them, and had no problem finding the certified glasses,” said club president Amanda Burk.

Contributing to this story were the Effingham, Illinois, Daily News, and the Mt. Vernon, Illinois, Register-News.