Astronauts Don Pettit and Matthew Dominick Joyfully Nerd Out Over Astrophotography
NASA hosted its first-ever Twitch livestream from the International Space Station (ISS) this week. Astronaut Don Pettit, who is on the ISS now, chatted with fellow astronaut Matthew Dominick, who returned to Earth last October.
Pettit, 69, the current oldest astronaut, is aboard the ISS for his fourth mission. He arrived at the ISS in September, so he and Dominick, 43, had time to work together in space. They are both extremely talented photographers, so it is no surprise they spent time shooting together in space. In fact, they did a livestream from the ISS together last October and spent a lot of time then chatting about photography.
In a goofy moment during the livestream this week, Pettit impersonated Dominick by playing out one of their “conversations” about selecting the best ISO setting for astrophotography.
“Matthew would say, ‘Don, what’s the native ISO that you want to run on your camera?'” Pettit impersonates, with his baseball cap on backward.
“Well, I think we should keep it around 6400,” Pettit replies.
In the playful back-and-forth with himself, Dominick argues for a lower ISO, and Pettit responds that the best ISO is the one that allows him to get the right shot.
Even in space, photography nerds geek out over optimal camera settings and image quality.
As Digital Trends jokes, “Watching the skit, some folks back may wonder if the microgravity conditions are starting to get to Pettit, but anyone who knows him, or has followed his social media posts, knows that he has a keen sense of humor. So we think he’s OK.”
Silly impersonations aside, Dominick and Pettit spent a lot of time during the live stream discussing photography projects aboard the ISS. Pettit explains the special kit he brought with him to the ISS this time, including specialized filters and a custom-built star tracking rig.
Pettit says he has been spending a lot of time photographing thunderstorms, sprites, and blue jets.
Star field from @Space_Station. Taken from the SpaceX Crew 9 Dragon vehicle showing the Southern Cross region using my homemade star tracker. Big thanks to @BabakTafreshi for doing the image processing I can’t do on orbit. pic.twitter.com/Tx4SmHXUXk
— Don Pettit (@astro_Pettit) February 12, 2025
“When you and I were on board, we were shooting thousands and thousands of images trying to capture red sprites,” Dominick replies. He then explains that Pettit had told him about a camera feature he didn’t realize could be helpful for shooting sprites: pre-release capture.
“That’s working out really well,” Pettit says of pre-release capture burst shooting. The ISS is armed with Nikon Z9 cameras, which allow astronauts like Pettit to capture photos before fully pressing the shutter, which is hugely beneficial when trying to photograph transient lighting events like red sprites.
“I’ve got it set for a half second pre-exposure, and I have it set on burst mode — this is the Nikon Z9 — and I’ve got the 200mm f/2 lens on, and I’m looking through the wharf window nadir straight down on thunderstorms,” Pettit explains.
“You can catch these storms, as soon as you see the flash, you mash the button, and it will have pre-recorded a half a second before you mashed the button so you can capture the whole thing.”
Pettit has been working with acclaimed photographer Babak Tafreshi on an amazing “From Above and Under” collaborative series showcasing thunderstorms from Earth, courtesy of Tafreshi, and as seen from space, thanks to Pettit.
Pettit has found it hard to capture red sprites from that perspective, even with pre-capture bursts, but he is photographing many blue jets.
“You’ll see the top of a thunderhead, and there’ll be a bright blue spot, it almost looks like a laser beam is coming out from somewhere in the thunderhead. It’s really interesting, and you might see that blue spot in one, maybe two sequential frames, and then it goes away. Sometimes it comes back maybe 30 or 40 frames later. To see these pink tendrils you typically think of as sprites, those I haven’t gotten a confirmed ‘This is a sprite,’ but the blue jets, it’s obvious when you see a blue jet.”
Although Dominick did not use pre-capture shooting when he was on the ISS, he did still get some amazing photographs of red sprites during thunderstorms.
The entire conversation is a treasure trove of fun facts for astrophotography enthusiasts. Don Pettit most recently recreated his famous 2012 photo, Lightning Bugs, from aboard the ISS. Pettit is scheduled to return to Earth in April, so he has plenty more time to capture fantastic photos and maybe even get that coveted red sprite shot.
