Strange clouds that glow in the night sky are getting easier to see — and it could be because of all the methane we’re pumping into the atmosphere, a new study says.
The bad news is that methane is a greenhouse gas that’s contributing to global warming. But the good news is that more methane means that more of us might get a chance to see these stunning, night-shining — or noctilucent — clouds, according to the study, which was published this week in the journal Geophysical Research Letters.
Noctilucent clouds form around the poles in the summer months, when ice crystallizes around shards of disintegrating meteoroids, volcanic dust, and even rocket plumes 50 miles above the surface, according to NASA. Here on the ground, we can see these clouds when the sun dips below the horizon and illuminates them. The first time people reported noticing noctilucent clouds was in 1880s after the massive eruption of Krakatau, a volcano in Indonesia. Back then, noctilucent clouds were spotted maybe a handful of times a century; now, it’s possible to see one or more noctilucent clouds every season, the study says.
That’s likely because they’re getting brighter. And new computer simulations suggest that’s because of rising levels of the greenhouse gas methane. Over time, methane in the atmosphere breaks down into carbon dioxide and water. That water vapor is responsible for the brightening noctilucent clouds, the new study says. More water vapor fuels more ice crystal growth, which means shinier clouds.
As far as consolation prizes go for the snowballing nightmare of climate change, these clouds are pretty stunning.
And of course, NASA’s taken some shots from space.
The most delightful roundup of noctilucent clouds, though, is this 2007 NASA montage set to an acapella song about them:
If you want to get a good shot of your own, all the standbys of nighttime photography apply, says Verge photographer Amelia Krales. First off, you have to get to the right place: you have the best chance of spotting noctilucent clouds with the naked eye at latitudes from 55 degrees north to 61 degrees north, the study says. That’s roughly from the bottom tip of Alaska to Anchorage, or from Glasgow, Scotland to the Shetland Islands.
Then, set the aperture on the lens nice and wide — an F-stop of about 1.4 — to let more light hit the camera’s sensor. And slow down the shutter speed, which is measured in fractions of seconds. “When you want to get in as much light as possible you may have a shutter speed of under 1/30, which is where the tripod comes in,” Krales says. Otherwise, a shaky grip on the camera could mean a blurry exposure. You can also raise the ISO — which increases the sensor’s sensitivity to light. And it’s best to shoot raw files rather than compressed formats like Jpeg, because raw files store the most digital information and retain nuances of tone and color.
“Technology has allowed us to take night pictures in a way we really couldn’t even 20 years ago,” Krales says. But, you’re on your own for the acapella accompaniment.