The first solar eclipse Fred Espenak saw was electrifying. It was March 7, 1970, and Espenak, who had just earned his driver’s license, drove his family’s car from Staten Island down to North Carolina. “I thought I was really prepared for the eclipse. And then the moon shadow swept over us, and we were plunged into totality,” he said, referring the zone of complete darkness that occurs when the moon passes between the earth and the sun and fully blocks the star.