Astronauts aboard the ISS take amazing snaps of Comet A3

Astronauts onboard the International Space Station often get a front-row seat to the most beautiful astronomical events. Most recently, two ISS crew members captured stunning photos of the passing Comet C/2023 A3 also known as Comet Tsuchinshan-ATLAS.

As it streaked across space, astronauts Matthew Dominick and Don Pettit tracked and photographed Comet A3. This was no easy feat as the icy object is barely visible to the naked eye even when viewed from the space station. The ISS crew members used some nifty math and orbital geometry to locate A3 in space.

"Wow, comet C/2023-A3 (Tsuchinshan-ATLAS) is growing a long tail! Canadarm is shown for scale.."

Source: Don Pettit @ Twitter

Dominick also shared that they had some help from an amateur astronomer and software on the ISS to approximate the comet’s position. According to him, A3 was roughly 20 degrees ahead of the Sun when viewed from the ISS.

"Still camera use is primarily Z9. Some D5s still in operation for specific tasks. This was taken with a Z9 with a NIKKOR Z mount 50mm, f1.2 lens"

Source: Matthew Dominick @ Twitter

The astronauts used a Nikon Z9 with Nikkor 200mm F/2 and 50mm F/1.2 lenses to capture images of Comet A3. Nikon’s flagship mirrorless camera is well-regarded in the photography community for its outstanding low-light performance. The Japanese camera maker sent a batch of unmodified Z9s to the ISS to help astronauts in astrophotography. The company will also be providing cameras to the Artemis III mission which will be used by the crew returning to the surface of the moon.

Comet A3 is currently moving towards the Sun and will not be visible until October 12 when it makes its closest approach to Earth. The comet will be approximately 44 million miles from Earth when it passes by.