Eclipse Over Big Sky Country

The eclipse plunged the snow-covered prairies in Central Montana into darkness for slightly more than two minutes. More than 500 astronomers and other eclipse enthusiasts riding in 15 buses selected a remote vantage point at the last moment, parking by the side of a country road near an abandoned farmhouse. The group's organizers, including two meteorologists, a former astronaut and a network of ham radio stations, coordinated information to guide viewers away from approaching storms and overcast skies....

The bus caravan, which carried the largest single group of watchers, was organized by Dr. Philip Sigler, a professor of sociology at the City University of New York, with his wife and brother-in-law, Theodore Pedas, planetarium director at Youngstown State University in Ohio. The Siglers have organized eclipse expeditions on ships and land since 1972, all of which have successfully evaded bad weather and other obstacles to convey large numbers of enthusiasts and professional astronomers to the best vantage points…

Experts on today's expedition included Dr. John A. Eddy, solar astronomer at the High Altitude Observatory in Boulder Colo.; Dr. Mark R. Chartrand 3d, chairman of New York City's Hayden Planetarium, and Dr. Frank D. Drake, director of the National Astronomy and Ionosphere Center at Arecibo, P.R.

Dr. Edward M. Brooks,professor of geophysics at Boston College, maneuvered the convoy of buses through the snow-covered mountain passes and range land of western Montana near Yellowstone National Park, plotting tactics against the weather like a general up against a wily and unpredictable enemy. …

With much of the North American continent under overcast, the task of finding a hole in the clouds large enough to look at the sun for two minutes proved a formidable task. For days in advance, Dr. Brooks, the meteorology guide on previous eclipse expeditions the group has made, plotted weather data and made dummy eclipse-chasing runs.

Dr. Brooks led the 15-bus convoy, escorted by sheriff's cars, from a radio-equipped jeep in continuous touch with weather stations in various parts of the country and with several aircraft in flight including one in which the former astronaut M. Scott Carpenter was sending direct weather reconnaissance.

Eclipses are not particularly rare. In the average century there are 237 solar eclipses, which includes 66 total solar eclipses, and 154 lunar eclipses, including 71 total lunar eclipses. But most of these are in out-or-the-way places, and many people pass their lives without seeing one.

Allowing for the fact that in a total eclipse the path of totality is about 100 miles wide, a total eclipse of the sun is visible from the same spot on earth only once every 360 years.

During the last century or so, astronomers have been able to go to remote eclipses intentionally, rather than having to wait for each one. Shipborne astronomy added many more eclipses to those to which land-based observers had been limited, and the airplane and space vehicles have still further expanded access to eclipses.

Consequently, there has been an explosion of knowledge about eclipses and the sun in recent years.