Backyard astrophotographer Andrew McCarthy has captured a stunning shot of the International Space Station (ISS) crossing a crescent moon.
What is unusual about McCarthy’s latest effort is the fact that it’s illuminated rather than silhouetted, allowing the viewers to see some of the space station’s features owing to shooting during Earth’s daylight.
The shot took a lot of preparation, involving McCarthy driving out to a remote part of the Sonoran Desert in Arizona to set up his elaborate gear in 105 degrees Fahrenheit heat.
“This transit happened at 16:50, so the Sun was still out,” he says. “That made the Moon much lower contrast and difficult to focus on using my equipment. Thankfully, the ISS still shines brightly enough to capture in conditions like this.”
McCarthy used two telescopes to capture the ISS which had 11 people onboard at the time.
“I use two telescopes for multiple reasons,” he explains. “Right now I miss about two-thirds of these shots I attempt, due to either equipment failure or weather.
“The second telescope helps eliminate variables. It also allows me to use both color and monochrome cameras, which have different strengths. This image was captured using both, so I was able to combine the final images.”
The ISS only appeared in the photographer’s frame for roughly a quarter of a second, which meant McCarthy has to be extremely precise.
“Due to the focal lengths used, if my position on Earth was off even slightly, the camera would have missed the transit entirely,” he adds.
The ISS flies at an incredible speed of 17,500 miles per hour (28,000 kilometers per hour) so McCarthy had to use n extremely fast shutter speed (1/5000 of a second).
“I was facing 15 miles per hour wind gusts the moment of the transit, usually that causes the atmosphere to distort the image, so I’m very thankful it came in clear. I felt a huge wave of relief seeing the station so clearly in my RAW images,” he says.
“There were 11 people on board at the time so it’s kind of cool to think I was taking a photo of them from the desert in Arizona, as they whizzed past at 17,500mph.”
“The detail I got on the ISS itself in this shot was incredible. Not quite enough to see any of them waving out the window though, I might need to upgrade my equipment for that,” he adds.
Image credits: All photos by Andrew McCarthy.