An image of two bright blue “blobs” photographed from space was recently shared by NASA. But it captures a strange though relatively normal weather event.
According to Newsweek, the mesmerizing photo was taken by an astronaut aboard the International Space Station over Southeast Asia. While the two blue blobs in the photo look relatively similar, they’re actually the result of two completely different phenomena.
Per the outlet, the first is the result of a lightning storm over the Gulf of Thailand. Lightning storms typically aren’t viewable from space. But the blue-white scene captured from outer space, by chance, resulted from a “gap” in the clouds. Tero Mielonen, a senior scientist at the Atmospheric Research Centre of Eastern Finland of the Finnish Meteorological Institute, offered further insight into the unique sighting.
“In [the case of the photo] you could see the lightning,” which therefore created the blue light, “because there was a gap in the cloud top,” he explained. He continued, “In addition to the regular cloud-to-ground lightning, there are also lightning [strikes] which don’t reach the ground.”
Per his statement, these instead remain within the cloud. They occasionally “have visible channels that extend out into the air around” and above the cloud. This, therefore, causes the blue light sensation seen from space.
One Blue Blob Shares Similar Traits to that of Earth’s Sky
Now that we know the origins of the blue blob in the photo seen hovering over the Gulf of Thailand, let’s take a look at the second one.
The second blob just barely appears in the photo taken from the ISS. It hovers just on the edge of the frame and, according to the outlet, was actually seen over the South China Sea. This strange event, however, was caused by the light of the moon.
The photo shows the light of the moon being viewed through Earth’s atmosphere. The color originates from the atmosphere’s scattering effect, which also accounts for the reason that our sky appears blue. Essentially, that scattering effect then caused the moonlight captured in the photo to appear the same blue as the lightning storm blob seen over the Gulf of Thailand. Mielonen offered further insight into the unique colors that occasionally appear in our planet’s atmosphere.
Exploring Earth’s ‘Transient Luminous Events’
According to Mielonen, there are a multitude of storm-related events that light up our atmosphere in unique colors. Speaking further about the blue light sensations we saw in the new photo, he explained that there are occasionally other colors that light up our atmosphere known as “transient luminous events.”
“The most common ones are sprites,” he explained. These “appear directly above active thunderstorms, and they tend to happen at the same time as cloud-to-ground lightning.” While they are faint, they also produce blue “jets” which emerge from the top of the cloud, sending out cones of light.
“Then there are elves,” he continued. Per his account, these expand rapidly and also glow, sending light much farther out. However, they only last “a thousandth of a second.”
The final light phenomenon is known as a red sprite which is a rare form of red lightning.