LAWRENCE — An experiment that sent three caterpillars to space where the bugs changed into monarch butterflies and lived for a week has been deemed a success.
The butterflies aboard the International Space Station fluttered around in a small container, as hundreds of students across the country watched and conducted their own experiments. The last of the butterflies died late Friday.
Not bad, said Chip Taylor, director of the Monarch Watch program and professor of ecology and evolutionary biology at the University of Kansas.
"They survived and did remarkably well, considering the disadvantages they were having up there in space," he said of the insects, whose normal adult life span is two to four weeks in the spring and summer.
Students watching at their schools during the four-week experiment saw the butterflies overcome several challenges.
For example, they saw all three butterflies emerge from a chrysalis that was floating in midair after it detached from the sides of the habitat.
The experiment helped introduce children across the country to the difficulties of life in space, Taylor said, and produced information about the monarchs' reaction to zero gravity.
"It does appear that monarchs have a gravitational sense," Taylor said. "The question is where is it and how does it work?"
For caterpillars that naturally want to move upward, an environment that presented no clear "upward" direction was confusing, Taylor said. A lack of gravity also contributed to the insects' struggle to naturally expand their wings.
About 600 individuals and schools watched the caterpillars develop as they orbited in the space station, about 220 miles outside the earth's atmosphere. The schools received caterpillars in a small rearing station similar to that in the space station, and compared their caterpillars' progress to those in space.
A specially designed artificial diet used in the space proved effective. Taylor said that may allow the Monarch Watch program to expand into inner-city schools, many of which can't find milkweed, the only naturally occurring food that monarch caterpillars will eat.