Share with friends and circles of friends with wechat scanning QR code < / P > < p > news on July 6. In recent days, the number of noctilucent clouds in high-altitude clouds has reached the highest level since 2007, and rocket launch activities may be one of the main reasons

noctilucent clouds are the rarest and highest clouds on earth. Recently, scientists have recorded more noctilucent clouds than at any time in the past 15 years. They look a bit like waves on the ocean in Impressionist paintings

in summer months, when water molecules freeze around dust particles in the atmosphere, noctilucent clouds will form in the upper air, creating an intoxicating artistic landscape over land. They often fluctuate, looking like waves in the ocean

most noctilucent clouds form in the mesosphere, which is about 31 to 53 miles (50 to 85 kilometers) from the ground. There is little dust floating in the middle layer, which can help water vapor condense and freeze. Most of the material formed by noctilucent clouds comes from meteor smoke. These meteors will burn and leave residues when passing through the upper atmosphere

however, other factors may also have contributed to the recent sharp increase in these clouds. For example, NASA has a spacecraft called aim (high altitude ice detection in the middle atmosphere), which is helping to study all the fascinating phenomena that occur in the upper sky

Cora Randall, a scientist and professor at the University of Colorado at Boulder, is responsible for processing the data of aim. She is one of the first people to confirm the sharp increase in the number of noctilucent clouds. Professor Randall said: "in the past few days, we have seen a surge in the number of noctilucent clouds."

at the end of June this year, the frequency of noctilucent clouds surged, far exceeding the peak in 2007. One possible reason is that SpaceX and other companies' rocket launch activities have increased significantly. Randall added, "we speculate that this peak may be caused by the delivery of additional water vapor to higher latitudes by rocket launch."

astronomer Tony Phillips once wrote that the water vapor emitted by many rocket engines takes about 10 days to float to the middle layer. This means that the surge of noctilucent clouds in late June may be related to the SpaceX launch on June 19

Randall warned that more analysis was needed to confirm whether SpaceX really played a role in creating more rare noctilucent clouds. SpaceX did not immediately respond to a request for comment

research also shows that noctilucent clouds are very sensitive to climate change, and their increased visibility may also be a by-product of global warming. (small)