The recent Quadrantid meteor shower in early January was something of a bust for most people; while it did produce shooting stars, it was not quite up to the rate predicted (absolute max of 100/hour, though for most people about half that). I hope to eventually see a paper saying why that might be.
But some folks got a good view of the shower. Amazingly, it wasn’t from someone who looked up to see the meteors burning up in our atmosphere. It was from someone who had to look down.
International Space Station astronaut Christina Koch tweeted this shot a couple of days after the Quadrantid peak:
WHOA. Look to the left: You can see several trails from bits of asteroid 2003 EH as they hypersonically plow through our upper atmosphere, about 100 km off the ground. At the time, the space station was 320 km higher yet.
When I first saw the photo I was alarmed, but Koch's caption eased my mind: She notes explicitly that this is a composite of several photos. Ah, that makes sense! A photo like this has a short exposure time, and the odds of catching a meteor at all are low, let alone 3, which is why my skeptical alarm bells were ringing.
I’m not sure how the photo was composited, though. Curious, I went to the Gateway to Astronaut Photography of Earth, a fabulous website that has a vast number of astronaut photos online. Better yet, they’re searchable! Knowing the peak of the shower was on 4 January, I limited my search to that date (click here, then click the "Uncataloged Image Search" button, then enter 4 January 2020 for both the start and end dates) and was able to quickly find the series of photos used for the composite.
If you do this, you can see the city — which I suspect is Edmonton, Alberta, given the ISS was southwest of it at the time — featured so prominently in the photo in many of the shots, moving to the lower left as the ISS moved around the Earth (the photos are displayed in reverse chronological order). There are several dozen shots, but it wasn’t hard to find a couple with meteor streaks in them:
The second shot was taken 31 seconds after the first; you can see the city lights have moved. The cloud cover has changed a bit, too, most likely due to the changing perspective of the station as it swept over the region at 8 kilometers per second. I tried to move the two images to make them overlay and it doesn’t work well due to the perspective change; when I shifted them so the city is in the same place the other bright spots didn’t match up correctly.
I suspect then that whoever made the composite cut out the meteor trails and pasted them into a different image — I'm sure I could find that master image if I poked through the archive a bit more. Feel free if you want to.
So that’s pretty cool! The photo is real, if composited (which I'm fine with — some hoaxers or content stealing accounts like to grab something like this and pass it off as a single shot, which is grossly misleading at best), and it shows something completely amazing: What a meteor shower looks like from space.
You may be wondering how dangerous it is to be in the space station during a meteor shower. The answer is: Not much. There's a risk, certainly, but it’s small.
Back in 2011, my friend and astronaut Ron Garan took an iconic photo of a Perseid meteor from the ISS. I wrote about it at the time (this was back when I was with Discover Magazine) and did a little bit of math to figure out just how risky it is. The number I got is that, on average, the ISS would get hit by a Perseid once every 8,000 years. Even adding up all showers, it's unlikely the station would get hit during any given astronaut’s stay. Over enough time, yeah, it will inevitably get hit by one, but we’re talking a timescale of centuries. So it's not a huge day-to-day concern.
I'll note they do have emergency patches on the ISS in case of a hole. Given that a typical meteor shower meteoroid is smaller than a grain of sand and moving at roughly 40–80 kilometers per second, it will leave a teeny tiny hole, punching right through the station wall as if it weren’t there. As long as it doesn't hit something vital, like a computer, an air tank, or, say, an astronaut, they'll have plenty of time to find the hole and fix it. The air would leak out very slowly.
The bottom line is the space station is small relative to the Earth, space is bigger yet, and the odds of it getting hit are low… but we keep putting more and more hardware into space. At least one if not two satellites have been hit in the past, causing them to lose control and forcing them to be shut down. The more we launch into the space, the more often this will happen, and it's something engineers need to be aware of.
One more thing: From the ground, we see meteors appear to come from a point in the sky called the radiant; it's a perspective effect. From space, the meteor trails should look parallel. But they don’t in the photo! I think again this is due to the motion of the station orbiting the Earth, but I'm not sure. The geometry here is a little tricky. If you have ideas, feel free to leave a comment below! I’m curious to know if anyone out there who has experience interpreting ISS photos of Earth has anything to say about that.