American Scientist

Seven years ago, on a trip to a part of Montana that was once Blackfeet territory, astronomer Judith Young saw a ring of stones that pointed the way to north, east, south and west. This prehistoric structure, called a sunwheel, was one of thousands of similar astronomical markers erected throughout the world in ancient times—including the famous site of Stonehenge in England. Young, who teaches astronomy at the University of Massachusetts in Amherst, began to wonder whether she could build a megalith for modern times, as a way of reconnecting ordinary people with the skies. Now, on the University of Massachusetts campus, Young's vision is about to become a reality.

Today we think of astronomy as hard science, carried out with gigantic telescopes on faraway mountain peaks. But it really began with people watching the sun. They watched for many reasons—for example, to tell which way was north (by observing the direction that shadows point at midday), or to mark the beginning of a new season (by observing when the sun sets at its northernmost or southernmost point). That's exactly what Young thinks is missing from astronomy today—the sense that it's something anyone can do.

Physicist, astronomer and writer Philip Morrison of the Massachusetts Institute of Technology agrees with her. In interviews with schoolchildren, he found that they don't think of the planets as something they can see in the sky. They experience the planets only through television, movies and the World Wide Web. As a result, astronomy seems removed from everyday life—as he says, "book-ified."

Young's goal for the Sunwheel project is to bring astronomy down to earth… more precisely, to a vacant lot near the football stadium and soccer fields on the UMass campus. In 1995, she won unanimous approval for the project from a campus committee. Getting money for it was a little harder. As she puts it, "The artists say it's not art, and the scientists say it's not science." A lot of the early funds came from sales of T-shirts and donations from individuals who visited the site, which at first consisted of nothing but wooden markers. In 1997, as more money came in, Young was able to replace the markers with two- to four-foot-tall stones. Finally, this year, she got the biggest prize of all—a $50,000 grant from the National Science Foundation that will allow her to build the full-scale version. She says, though, that the time spent selling T-shirts was well worth it. "I had to put out a tremendous effort to get the word out to schools and the community," she says. "[The grant] came when I was ready for it, after two seasons of letting the public know the Sunwheel is here."

When complete, the Sunwheel will be 60 feet in radius, with standing stones 8 feet tall marking the sunrise and sunset at the solstices. as well as the four compass points—the arrangement she found in Montana, but on a larger scale. Placards will explain what to look for, and suggest experiments that visitors can do themselves. For example, visitors can determine the angle of elevation of the sun by observing the length of a stone's shadow. If they are dedicated enough to come back at the equinox and on the summer and winter solstices, they can use the angle of elevation on those days to figure out that the earth's axis is tilted by 23.5 degrees.

Unlike the builders of Stonehenge, Young is taking full advantage of modern construction equipment, hauling the stones from a local quarry in trucks. According to Morrison, who has observed the progress of the project, there was no need to duplicate the methods or the appearance of Stonehenge: "It's not faithful to any particular site. What it's faithful to is the sky."

The full-scale Sunwheel was scheduled to be built in October 1999. Unfortunately, the astronomer's oldest enemy got in the way. "Between August and today we haven't had three dry days in a row," said Young on a rainy day in October. Because of the heavy rains, the field (which is on the site of a glacial lake bed) became too waterlogged for heavy trucks to drive across, and construction had to be postponed until next summer.

Young is unfazed by the delay. ("You sound more disappointed than I am," she tells me.) Instead, she is heartened by the positive response that the smaller-scale Sunwheel has already drawn in two years. It has become a popular field trip for school groups as well as a meeting spot for the community. A group of modern-day Druids has even put her on their e-mail list. Most encouraging of all are the letters she gets from visitors to the site. "At least three young girls have written to me and said they wanted to be astronomers," she says, "because it looks like fun."—Dana Mackenzie