ONE ASTRONAUT, MANY CAMERAS

220 DAYS OF AMAZING IMAGES FROM SPACE

- STORY: KENNETH CHANG / NYT

Don Pettit, Nasa’s oldest active astronaut, returned to Earth on April 20, the day he turned 70 years old. That concluded his fourth trip to space — a busy 220 days at the International Space Station.

Like other crew members on the space station, Pettit conducted experiments, talked with students and exercised for hours to maintain his health and to stave off loss of bone density. But the most eye-catching work he performed in orbit was his photography.

Most people will never get a chance to go to space.

"I could try to give them a glimpse through my imagery," Pettit said during a news conference a couple weeks after his return.

Pettit noted that hard-core photographers always want to have a camera in hand.

"I could look out the window and just enjoy the view," he said. "But when I'm looking out the window, just enjoying the view, it's like, 'Oh, wow, a meteor. Oh, wow. Look at that. Man, there's a flash there. What's that?! And, 'Oh, look at that, a volcano going off! It's like, 'OK, where's my camera? I got to record that."

Sometimes he set up five cameras at once in the space station's cupola module, where seven windows provide panoramic views of space and Earth.

Space photography is often much like night photography. Stars are dim, and exposures lasting seconds or minutes are needed to gather enough photons. But in orbit, nothing is sitting still. The space station is zooming around Earth at 7.66km per second, and Earth is also rotating.