Astrophotographer snaps moment the ISS transits a crescent moon at more than 17,000mph

The moment when the International Space Station (ISS) travels more than 17,000 miles per hour across a crescent moon was captured in a stunning image by a backyard astrophotographer.

Andrew McCarthy, who takes great photos of the cosmos, recently shared a photo showing the huge, 100-meter-long orbiting lab as a shiny speck against the backdrop of a massive crater moon.

McCarthy said he drove to a remote location in the Sonoran Desert and set up his gear among cacti in the 105°F heat, hoping to capture details of the station that are rarely visible in photographs.

“This transit occurred at 4:50 p.m., so the sun was still out,” he said.

‘That made the moon much less contrasty and difficult to focus with my equipment. Fortunately, the ISS still shines bright enough to capture in conditions like this.”

The ISS is 254 miles above the Earth’s surface and 238,900 miles from the Moon.

The massive craft moves five miles per second and completes a full lunar transit in about half a second.

McCarthy placed two telescopes in the desert in case one failed during the mission, which he said had happened in the past.

“I use two telescopes for several reasons,” McCarthy shared in a press release.

“Right now, I miss about two-thirds of the shots I try because of equipment failure or the weather.

‘The second telescope helps to eliminate variables.

“It also allows me to use color and black and white cameras at different strengths. This image was shot with both, so I could combine the final images.’

However, McCarthy only had a moment to capture the ISS transit over the moon – a quarter of a second, really.

“Precision during the catch was paramount,” he said.

“Because of the focal lengths used, the camera would have missed the transit altogether if my position on Earth was even slightly off.”

The ISS moves at a whopping 17,500 miles per hour, so the camera’s exposure had to be very short to avoid motion blur.

“I was shooting at exposures of 0.2 ms (1/5000 s), but even with such short exposures the station moved about 2 meters within each shot!”

McCarthy hopes to inspire a new generation of space explorers.

“Images like this really turn me on,” McCarthy said.

“It’s a juxtaposition of the past, present and future of space exploration. I call this “New Frontiers” because it makes me think about the Lunar Gateway and the future of the Artemis mission.

“Perhaps the first person to set foot on Mars will see it and feel inspired!”