It's been quite a ride for wacky science teacher Ms. Frizzle and her students, who have been enthusiastic passengers on the soaring Magic School Bus for two decades. Launched in 1986, this spirited science series by Joanna Cole and Bruce Degen encompasses 131 titles over a variety of formats and has sold more than 58 million copies.

In 1994, the Magic School Bus crew made their debut in an animated TV series produced by Scholastic Media with support from the National Science Foundation. Starring Lily Tomlin as the voice of Ms. Frizzle, the series has received multiple awards, including a Daytime Emmy. Warner Home Video's seven Magic School Bus DVDs have sold more than five million units.

And, as it prepares to celebrate the series's 20th anniversary, Scholastic will release The Magic School Bus and the Science Fair Expedition, the 11th picture book in the series and the first in seven years. A 50,000-copy first printing is on order for this September title.

On Friday, September 15th, Scholastic has arranged for NASDAQ to dedicate its opening to the Magic School Bus's anniversary. Deborah Forte, president of Scholastic Media, will make an introductory speech and lead the countdown to open the market that day. Author Cole and illustrator Degen will be on hand, as will a costumed Ms. Frizzle. These three will also be the guests of honor at several bookstore events over that weekend. Fans visiting the Scholastic Store on Manhattan's Mercer Street, where the trio will appear on Saturday, September 16, will have the chance to climb aboard the brightly decorated Magic School Bus parked outside and experience interactive games and exhibits based on various science topics. The publisher has also created a 20th-anniversary poster featuring science activities on the back. And, to mark this milestone, Scholastic has repackaged the paperback editions of the 10 original picture books in the series.

Discussing the genesis of the Magic School Bus series, Craig Walker, v-p and senior editorial director at Scholastic, recalls, "In the 1980s, during the great era for picture book sales, we kept getting requests from teachers who were interested in seeing more books in the science category. So we had the breakthrough idea of putting curriculum science inside a story. I remembered as a child loving to go on field trips. So I thought about doing books about kids going on field trips to places they really couldn't: through a water system, to the bottom of the ocean, inside the earth. And I remembered an eccentric second-grade teacher in my school who everyone thought was the best. She brought everything imaginable into her classroom—even a teepee—and had every corner, ledge and windowsill filled with things. So that is where Ms. Frizzle came from."

And since Walker knew that Cole wrote both humor and science, and he was familiar with Degen's artwork, he asked them if they were interested in taking on the project. He was thrilled when they both agreed. "They got on so well from the start and respected each other enormously," he notes. "Bruce was very interested in the science aspect and Joanna is very art-oriented, so they clicked and were able to add to each other's ideas. To me that is 70 percent of the series's success. And putting nonfiction inside a fictional story really appealed to teachers, whose support has been largely responsible for making the series so popular."

In order to incorporate breaking science news into their backlist titles, Cole and Degen, with the help of experts in specific fields, update the content and look of each Magic School Bus picture book every few years. The author reports that even after 20 years, she and Degen have no trouble coming up with new science ideas for their books. "There are so many ideas, and so little time to write them all," she says. "We try to choose subjects that fascinate us and that we hope will fascinate readers."

One of the biggest challenges in making learning exciting for young readers, Cole says, is simplifying complex material. "We have to make it simple enough for kids to understand, but not so simple that the meaning goes out of it." From Degen's perspective, key challenges are "keeping a good sense of humor, sifting through tons of information and keeping focus on the basic questions of the subject."

Based on the positive response of parents, teachers and kids, the series's creators are meeting these challenges quite impressively indeed.