Astronaut photographs strange iridescent clouds at the edge of space

Astronaut Matthew Dominick was flying about 17,000 miles per hour above Earth when he looked out the window and saw this remarkable view.

Dominick, who was sent to the space station in March as commander of the International Space Station, NASA‘S SpaceX Crew-8 mission, grabbed its camera and snapped the above photo. Taken on July 4, the image is as stunning as any fireworks display back home.

Under a thin curl of the moon is a high bed of so-called noctilucent clouds, floating in the calm before the stormy sunrise. These strange high flying clouds on the edge of room — which mesmerized scientists just two decades ago — are easily observed from the space station’s orbit, about 400 kilometers above Earth.

“We have had so many beautiful sunrises lately with amazing night clouds,” Dominick said on Xformerly Twitter. “I’ve probably taken about 1,000 pictures of it in the last week.”

Tweet may have been deleted

Since the 19th century, astronomers have been looking to the sky and wondering what these clouds, the highest in Earth’s atmosphere, have to offer. Rain clouds typically don’t form higher than 10 miles, but noctilucent clouds float about 50 miles above the planet’s surface in a layer of the atmosphere known as the mesosphere.

From the ground, people have often called them “night-shining clouds” because their height allows them to continue reflecting sunlight well after sunset. In the summer, these iridescent clouds shine at sunset and sunrise near the North and South Poles.

How they formed remained a mystery until NASA Aeronomy of ice in the mesosphere (AIM) mission in 2007. Scientists knew that noctilucent clouds could vary with latitude and solar activity, but did not understand why.

Using a spacecraft orbiting 560 kilometers above Earth, researchers discovered that the clouds form when ice crystals condense on meteor smoke, tiny particles of falling stars that burn up in the atmosphere. Perhaps even more surprising was that the ice in the mesosphere forms in a single continuous layer.

NASA’s AIM mission captured the first global image of iridescent polar clouds in June 2007.
Source: NASA

In its first year, the mission documented the “life cycle” of noctilucent clouds in the Northern Hemisphere, which began in late May and continued through August. The satellite, which was only planned for a two-year study, provided 16 years of data before the battery is empty last year.

The observations led to many discoveries, including how events closer to the ground could cause changes in the clouds, and how the icy layer in the upper atmosphere could create eerie radar echoes in the atmosphere in the summer. Scientists credit the spacecraft for its success, especially given the obstacles it faced early in its mission: A faulty receiver forced NASA’s team to figure out how to reprogram it to communicate in Morse code.

One of the mission’s most recent findings is how humans are affecting cloud formation. Study 2022 published in the magazine Earth and space sciences found that morning rocket launches could create noctilucent clouds even further from the poles, over southern Alaska, central Canada, northern Europe, southern Scandinavia and south-central Russia.

The crew of the International Space Station sees noctilucent clouds over the southernmost tip of South Korea late in the evening of July 1.
Photo: Matthew Dominick / Earth Science and Remote Sensing Unit / NASA Johnson Space Center

Researchers compared the spacecraft observations with the timing of launches south of 60 degrees north latitude. What they found was a strong correlation between morning launches and nighttime clouds at the relatively lower latitudes.

Despite the end of the AIM mission, Cora Randall, deputy principal investigator, said in a statement that scientists will continue to make new discoveries based on the data.

“There are still gigabytes and gigabytes of AIM data that need to be studied,” she said.