Scott Kelly holds the American record for the most consecutive days in space, spending 340 of them in orbit aboard the International Space Station before returning to Earth in March 2016.
Kelly took hundreds of photographs while he was in space, many of which he shares in his new book "Infinite Wonder: An Astronaut's Photographs from a Year in Space."
"Photography is a big part of the job, we get a lot of training in it," Kelly tells Here & Now's Jeremy Hobson. "But it really wasn't until I was living on the space station for long periods of time that I developed not only a little bit of a skill for it, but also a love for taking pictures — particularly pictures that have some artistic value to them."
Speed was one challenge Kelly says he had to overcome to ensure Earth was ready for its close-up: The space station moves at around 17,500 miles per hour, or about 5 miles per second.
"It takes a while to develop a good technique — I think months, actually," he says. "Sometimes you get blurry pictures, but other times you get pictures ... that I think people find mesmerizing and interesting."