WHEN Christopher Columbus used the stars to navigate his way to the New World 500 years ago, he probably didn't think about the stars themselves as new worlds to explore.
After a year of quincentenary commemorations of Columbus's famous voyages, "Where Next, Columbus?" - a new exhibition at the Smithsonian Institution's National Air and Space Museum here - takes visitors ahead into the next 500 years, coaxing them to think like explorers.
"We broke [museum tradition] to look ahead," says Martin Harwit, director of Washington's most visited museum, which houses the actual airplanes and spacecraft that have made aeronautical history.
"The only literature children have that guides them to the future is science fiction," Mr. Harwit says. "The only problem with that is [understanding] what is reality and what is story line.
"We hope to inspire our visitors to begin thinking about ways of building spacecraft to travel faster, farther, and more economically," he adds. "We also want them to examine the contributions of past and present robotic probes and consider the potential of robots as alternatives to human explorers."
In a sort of introduction to space-age vocational training - which 60 corporate and industrial vice presidents of research helped museum curators develop - museumgoers are taken beyond mere science-fiction fantasy.
Visitors are led through multimedia devices and simulated settings in outer space to contemplate the parallels in thinking between explorers like Columbus and today's astronauts - and even possible extraterrestrial explorers. Politics, technology, economics, and pure curiosity were all behind Columbus's adventures, and they are also the primary motives for today's space exploration.
To the children of people who were children themselves when they watched men walk on the moon, National Aeronautics and Space Administration (NASA) space-shuttle launches may seem as common as television re-runs. But even for them, a few moments in the simulated infinity of the exhibit's Stellarium can inspire the peaceful, but gripping, awe of the universe that opens thought to the kind of imagination necessary to get full benefit from the rest of the exhibit.
The Stellarium is a three-dimensional scale model of the Milky Way galaxy, whose actual diameter is 100,000 light- years. Picture yourself in a pitch-black room, with 700 pinpoints of light scattered like a crystal-clear night sky surrounding you. (The points of light are actually the lighted tips of fiber-optic strands.) Time spent here brings home a sense of vast possibility.
One such possibility is intelligent life somewhere other than Earth. Astronomer Frank Drake guides visitors through an interactive logic game on video to estimate the probability of advanced civilizations existing in our galaxy.
How many stars are there? And for each star how many planets could there be? And of these planets, how many are likely to be able to support life? And what is the likelihood that that some form of life is there today? The visitor gives an answer for each part of the equation in order to come up with his or her own answer to the question: "Are we alone?"
While a historic time line puts space exploration into its context in humanity's historic proclivity to roam, the exhibit's strongest parts are those that draw visitors into "participating" in possible future scenarios.
The "Exploring New Worlds" section of the gallery is a 3,000-square-foot Martian landscape with authentic-looking boulders, steep canyon walls, and a vista across a Mars valley. The realistic scene was designed by using satellite data to determine the size, shape, color, and texture of the rocks in the landscape. With special lighting, the effect is the actual look and feel of the Kasei Valles formation on Mars.
Among the boulders are set interactive videos in which visitors can join a human mission to Mars or plan a robotic mission to the planet. Satellite data - such as temperatures, soil types, and land formations - are offered as options for choosing a base site on Mars.
Another program allows the visitor to design the features best suited for a robot to be sent to the Mars site. As a budget gauge along the side of the screen ticks off the millions of dollars being spent on each decision, the participant must go through the costly process of picking the best features to include in a robot configuration - such as legs or wheels, or both.
"We're only tentatively spacefarers - since 1972 no one has visited the moon in person. We've proven we can explore worlds beyond our own, but we're not sure it's something we want to do. We haven't yet decided what our spacefaring future is," observes Valerie Neal, the curator of the exhibit.
"This exhibit should raise questions about the prospects for future exploration," she says.
It will also add several interesting hours onto visits to the Air and Space Museum, which already can hold the attention of children and adults alike for a full day of discovery.