[Reading Science] The Increasingly Intense 'Yagwangun' Phenomenon... A Sign of Earth's Doom?

Observed in the Arctic Late Last Month, Unusually Early
Observation Range and Intensity Increasing
Water Vapor Crystals Formed at Altitude 70-80km
Atmospheric Pollution Including Methane Gas Increase Suspected Cause

Clouds usually cannot be seen at night. However, recently in the Earth's Northern Hemisphere, the phenomenon of noctilucent clouds, which glow and brighten the night sky, has been intensifying. As a result of air pollution, some have raised concerns that this might be a 'sign of Earth's destruction.'

Nightglow phenomenon. Photo by NASA website

First, the timing of their appearance is getting earlier. On the 5th (local time), the US space weather specialized media 'SpaceWeather.com' reported that noctilucent clouds were observed for the first time this year in Denmark the previous night. Considering that noctilucent clouds usually appear between late June and late July in midsummer, this observation was unusually early by nearly a month. Earlier, on the 26th of last month, a week prior, the NOAA-21 satellite belonging to the US National Oceanic and Atmospheric Administration (NOAA) also observed noctilucent clouds in the Arctic region.

The intensity is also increasing, and the observable area is expanding. Last summer, the intensity of noctilucent clouds was the strongest in the past 15 years. Previously, they could only be seen around the Arctic Circle, but nowadays they have moved southward enough to be observed not only in northern Canada but also in states like Utah and Nebraska. In mid-latitude regions, they can be observed around twilight when the sun lingers near the horizon.

Noctilucent clouds observed in the night sky are composed of faint blue, silver, and golden stripes, making them endlessly beautiful. Generally, clouds form at an altitude of about 10 km, but noctilucent clouds are created at a much higher altitude of 76 to 80 km, above the stratosphere, and are sometimes called 'Space clouds.' This is because they are generated and observed at an incredible height slightly below about 100 km, where Earth's atmosphere ends and outer space begins.

Phosphorescent clouds photographed at the International Space Station. Photo by NASA website

However, it is difficult to simply enjoy watching the beautiful night sky with curiosity. Noctilucent clouds form when water vapor attaches to dust and particles at high altitudes, freezes, and then reflects sunlight. They can also be caused by meteors burning up in the atmosphere. The problem is that they can also be generated by air pollutants. In fact, noctilucent clouds were first historically observed in 1885, two years after the Krakatau volcano eruption in Indonesia. Experts believe that volcanic ash and methane gas produced by the eruption rose to high altitudes, where water vapor attached to them and reflected light, forming noctilucent clouds. In particular, the US National Oceanic and Atmospheric Administration (NOAA) states on its website that "no observations were made before 1885" and that this phenomenon is considered a sign of climate change caused by increased methane gas in the atmosphere.

Some experts analyze that the increased frequency of noctilucent cloud appearances is due to the New Space era, with more frequent space rocket launches. Private space companies like SpaceX are launching many more rockets than before. As rockets reach high altitudes and release exhaust gases and water vapor, noctilucent clouds are becoming more frequent and intense. Especially last year, on January 15, the underwater volcano in Tonga in the South Pacific erupted with record intensity, injecting a massive amount of water vapor and volcanic ash into high altitudes. It was also a year with a record number of space rocket launches, with 186 launch attempts and 180 successes.