Figuring

by Maria Popova

Carl Sagan made one other monumental contribution to our civilizational canon in the course of the Voyager mission, the primary purpose of which had been not as poetic vehicle for the Golden Record but as scientific probe to explore and document the outermost planets of the solar system. Among the 105 kilograms of scientific instruments aboard these twin poems of aluminum and electricity was a camera, bound for interstellar space less than a century and a half after Talbot’s crude attempts to capture light and shadow. As the Voyagers sailed away from Earth at 35,000 miles an hour, they took spectacular technicolor images of the outer planets—the first-ever complete portrait of our cosmic neighborhood. They saw for the first time, in rapturous detail, the Jovian moons Galileo had glimpsed as faint spots and named after Roman deities nearly four centuries earlier. They saw Uranus, the color of Margaret Fuller’s eyes, its aquamarine so arresting and thoroughly unexpected that it extracted audible gasps from the imaging team on the ground. They saw what no human imagination had fathomed before: Navigation engineer Linda Morabito, glancing back over the shoulder of the spacecraft to take one final photograph of Jupiter, was stunned by the sight of an enormous umbrella-shaped plume emerging from behind its moon Io. In an instant, she was seized by the certainty that she was seeing the first known evidence of active volcanism on a world other than Earth—a Vesuvius four hundred mi...