The atmosphere of Pluto, which has grown for about 30 years, began to collapse in a surprising way, according to scientists’ recent observations. According to the data, the atmospheric pressure of Pluto has decreased by 20% since 2016.
It is not easy to observe the atmosphere of the old full planet Pluto, which is reclassified as a ‘dwarf planet’ revolving around the sun. Astronomers in our world wait for Pluto to pass in front of a distant star, so astronomers observe the influence of Pluto’s atmosphere on starlight. When this incident took place in 2016, a trend that astronomers have observed since 1988 was again confirmed and it was found that Pluto’s atmosphere was growing.
All this trend seems to be reversed now. Ko Arimatsu and colleagues from Kyoto University in Japan, who observed Pluto through a similar incident in July last year, revealed that the atmosphere of the dwarf planet collapsed. According to the data of astronomers, atmospheric pressure in Pluto has decreased by more than 20% since 2016.
What is known about Pluto’s atmosphere:
Astronomers knew for a long time that Pluto’s atmosphere expanded as it got closer to the Sun, and narrowed when it moved away from the Sun. When the sun heats the icy surface of Pluto, the surface sublimates and releases nitrogen, methane and carbon dioxide into the atmosphere. It is believed that when the sun goes away, the atmosphere freezes and falls down from the sky causing one of the most extraordinary storms in the Solar system. Pluto passed the closest part of its orbit to the Sun in 1989 and has been moving away from our star ever since. The atmosphere of the dwarf planet, however, continued to grow to a level of 1 in 100,000 of the Earth.
In 2015, the images of New Horizons, a spacecraft passing by Pluto, saw an ice-covered basin called Sputnik Planitia that stretched across the hemisphere. Planetary geologists think that this basin plays an important role in regulating Pluto’s atmosphere because this basin starts releasing gas into the atmosphere when it faces the Sun. This is why Pluto’s atmosphere is expanding despite the distance from the Sun, considering the simulations.
The same simulations show that Sputnik Planitia should have started to cool down since 2015, which must be one of the reasons for atmospheric pressure to drop. There is a small problem, however; According to the calculations of Japanese scientists, Pluto’s atmosphere should have shrunk by 1% during this time, but over 20% shrinkage was observed. This shows that there should be other factors than the known ones. It is pointed out that the telescope used by astronomers in observation is small and inadequate and larger telescopes are needed.