ANDOVER — Only 10 years old, Madelyn Reppucci never imagined she would travel to the center of the Earth.

But Madelyn and her classmates got the chance yesterday when they stepped inside a 20-foot-high inflatable globe sitting in the middle of the South Elementary School gymnasium.

"It was my favorite part going inside the globe," the fourth-grader said. "I have this new picture in my head of what the Earth looks like inside."

More than 100 children got the chance to sit inside the "Earth balloon," thanks to the school's parent-teacher organization and a grant from the Andover Fund for Education. Once inside, they received a geography and science lesson they will not soon forget.

They found out that the Pacific Ocean is much larger than a textbook map would have you believe, and how when it's Wednesday in the United States, it is Thursday in New Zealand.

"This brings it to life for them. It gets the kids thinking," said parent Andrea Monderer, who helped organize the event. "They talk about time differences, rain forests, volcanoes, global warming. ... It surprises you how much they already know at this age."

The gigantic globe comes via Earth Adventure, a Minnesota-based nonprofit organization that travels to schools across the country teaching children of all ages about their planet. The balloon is made of hundreds of satellite photographs, minus the cloud cover that usually blocks some of the view.

Cidalia Pina, a program facilitator with the organization, said the program makes news events become real for students.

Students gave a "wow" as she pointed out where a tsunami hit in the Indian Ocean in 2004, wiping out the part of the Indonesian coast. She used her laser pointer to show students how far away places like Iraq and Afghanistan are from Andover.

"Teachers have to teach to standards. Things like geography and Earth science are often left behind in the classroom," Pina said. "This helps finish off the curriculum. ... Kids usually see the world as a flat surface in a textbook. With this they get a good idea of scope and perspective."

Monderer hopes to bring the program back to South Elementary School next year, expanding it to other grades. John Kelly, 10, said he wouldn't mind another trip around the world.

"The best? Watching it inflate," John said.