But Liebenberg isn’t traveling for the August 21 eclipse. This time, his home in Salem, South Carolina, is smack-dab in the path of totality, a 70-mile-wide stretch of land that will experience the fullest effects of the eclipse, like a sash of darkness draped across the country. Liebenberg will set up his instruments in his driveway and watch with his family. After all these years, he hasn’t tired of nature’s wondrous performance.
“The onset of the darkness provides a somewhat eerie feeling, and then the shadow sweeps over. It’s an awesome sight,” Liebenberg, 85, said. “I appreciate the fact that people have spent lives and time and effort to make calculations so that I am in the right place and here is, in fact, a total eclipse.”
In his early eclipse-chasing days, Liebenberg would go to the library and check out catalogs that listed upcoming eclipses; despite its rarity in any one place, a total solar eclipse is visible from somewhere on Earth every year and a half, and math-savvy people can predict them thousands of years into the future. His trips were often funded through laboratories or other scientific institutions, like Los Alamos Scientific Laboratory in New Mexico, where he worked for many years. Sometimes he had to pay his own way. Eclipse chasing, he said, has never been “what pays the bills.”
Some eclipses have been better than others. For Liebenberg and other eclipse watchers, clouds are the biggest enemy. In 2013, Liebenberg flew to Uganda to catch an eclipse that would produce just 20 seconds of totality. His viewing spot was moved at the last minute because the Ugandan president would be there, and his tour leader thought it best to avoid the crowds and security measures that would accompany the high-level visit. The original spot saw clear skies, while the new site greeted Liebenberg with a big cloud, blocking his view of the eclipse entirely.
The trick to dodging cloud cover is to fly. Liebenberg has witnessed several solar eclipses from inside a Boeing NC-135 plane as it wound its way through the narrow ribbon of the moon’s shadow—a complicated operation, particularly in the days before GPS. “You have to be overtaken by it and push yourself along the path,” Liebenberg said. “And it’s easy, at 500 miles per hour, to slip out of the bend of totality.” The pilots maneuvered to stay inside the path of totality as long as possible, allowing passengers to experience the darkness for longer than they could if they were watching from the ground below—and giving the term “eclipse chasing” a whole new meaning.
That’s how Liebenberg spent 74 minutes in totality in 1973—far longer than possible while on the ground, where totality usually lasts for only a few minutes. Liebenberg and other researchers observed a solar eclipse that year over Africa from the perch of a Concorde, a supersonic aircraft built jointly by the British and French. Liebenberg wore a fire-resistant U.S. Air Force flight suit. When the moon overtook the sun, turning the sky a deep purple, the Concorde was hurtling at Mach 2.08, riding the path of totality across the continent at more than twice the speed of sound.