A sudden increase in the number of silvery clouds has been recorded, the most significant in the last 15 years

Something unusual has just happened in the mesosphere. At the end of June, NASA's AIM spacecraft recorded a sharp increase in the frequency of noctilucent clouds (NLC), the largest in the last 15 years.

"In the last couple of days, we've seen a huge surge of silvery clouds," says Cora Randall, a professor at the University of Colorado at Boulder. Randall is working with AIM data, and she has prepared the graph shown above.

NLC is the highest clouds on Earth. Seeded by meteoroids, they hover at the edge of space at an altitude of more than 80 km above the earth. NLCs are formed when summer clouds of water vapor rise into the mesosphere, allowing water to crystallize around meteorite smoke particles.

Oliver Schwenn observed this outbreak on June 30 from Aarhus, Denmark:

"I photographed this phenomenon shortly before midnight," says Schwenn. "The clouds shone brightly in the night sky."

What is the reason for this? Maybe it's SpaceX.

"We assume that the surge may be caused by additional water vapor carried to higher latitudes when launching rockets," says Randall. "But in order to confirm this or not, much more quantitative analysis will be needed."

Time makes sense. Water vapor from rocket engines takes about 10 days to rise into the mesosphere. This brings us back to the launch of the Globalstar satellite by SpaceX on June 19, which caused a number of amazing phenomena in the sky due to the additional burning time of the second-stage engine.Gorenje. Night clouds may be another byproduct of this unusual launch.

Night clouds are usually a polar phenomenon. However, after the outbreak began, we received reports of night clouds from southern Washington and Oregon. Look for clouds, pock-marked and electric blue, just after sunset.