Sometimes the universe went easy on them. A comet, visiting from the edges of the solar system, showed up a week after Pettit reached orbit. Tafreshi observed the bright object in Puerto Rico, but Pettit “had the best view,” without Earth’s hazy atmosphere, with its pesky clouds, in the way. Not long after that, a major aurora storm appeared in the skies over Tafreshi’s house—how convenient!—and the photographers captured the event within hours of each other, their best timing of the entire endeavor. When it comes to the rippling, mystical green lights, two views are better than one. “If you look at the same ripple from orbit, you might find that it’s actually an oval,” Pettit said. It’s as if they had surrounded the shimmering phenomenon, revealing its true nature.
While Pettit was spared the difficulties that can ruin a photographer’s day on the ground—rainy weather, for example—his cameras would occasionally malfunction because of the constant, invisible barrage of cosmic radiation, and now and again artifacts of astronaut life sneaked into his shots. Once, Tafreshi was scanning Pettit’s images of the Maldives, in the Indian Ocean, when he noticed an intriguing patch of green in the water—an algal bloom? “I was so excited until I got the next few shots and I realized, This patch is moving very fast,” Tafreshi said. It turned out to be a weight-lifting machine, reflected in the space station’s windows. “Every crew member works out on this machine for an hour and a half a day,” Pettit said. He would occasionally ask his colleagues if they wouldn’t mind turning off the lights and working out in the dark, just for a few minutes. Not everyone obliged.