By The European Times | Created at 2026-08-10 06:56:55 | Updated at 2026-08-10 08:37:50
2 hours ago
Pluto is moving away from the Sun for the first time since 1930. Its atmosphere may have frozen: the pressure has dropped by 16% in two years. These are the first signs of collapse, according to astronomers.
Pluto’s Collapse
Pluto is a dwarf planet with an elongated orbit. It successively approaches the Sun and then moves away at enormous distances. Currently, Pluto is in a phase of outward movement, which is the first time the planet has made this movement since its discovery in 1930. Calculations show that in 2114 Pluto will reach its maximum distance and then turn around. But before that, it will have a long journey in cold and darkness, where sunlight is getting weaker and weaker. And its atmosphere will cool along with it.
Pluto’s atmosphere is a thin shell of nitrogen mixed with methane and carbon monoxide. It’s so thin that it’s only a few millionths as thick as Earth’s. But even that can freeze and settle on the surface as frost if it gets too cold.
A team of researchers led by Amanda Sikafus of the Planetary Science Institute in the United States tracked changes in Pluto’s atmosphere from 2017 to 2023 using a rare astronomical phenomenon called a total eclipse. Total eclipses occur when Pluto passes directly in front of a distant star. As the starlight passes through the dwarf planet’s atmosphere, scientists can measure how much it is attenuated. This attenuation can be used to determine the density and pressure of the atmosphere.
The team has observed 10 such total eclipses since 2017, but only in four cases has the event been recorded simultaneously from multiple locations on Earth. Measurements show that from the New Horizons flyby in 2015 until mid-2021, Pluto’s atmospheric pressure has remained roughly constant. But then, between mid-2021 and July 2023, something unexpected happens: the pressure drops by 16%.
This is the first direct evidence that Pluto’s atmosphere may be starting to shrink. As the surface cools as it moves away from the Sun, the nitrogen that evaporates from the surface and sustains the atmosphere stops flowing—it simply freezes back into ice.
“Our observations show that the atmosphere has recently started to lose pressure. I hope that in the coming years and decades we will be able to get more data to definitively confirm or refute this trend,” says Amanda Sikafus.
Pluto’s atmospheric haze, made up of complex organic compounds, should also change: as the pressure decreases, it will settle to lower altitudes and become less dense. The exact physics of these processes, however, are not yet fully understood – they are closely related to the behavior of ices on the surface.
Pluto offers scientists a rare opportunity to observe how its atmosphere changes over the course of a single season (which lasts about 250 Earth years on Pluto). And now, for the first time in recorded history, they are seeing it in a phase of cooling and possibly freezing. In 2114, Pluto will begin its return to the Sun, and its atmosphere will likely recover.
“But to see this, we will have to wait almost a century. In the meantime, we are witnessing the slow fading of the atmosphere of the most distant planet ever studied,” says the scientist who led the study.
The study was published in the scientific journal The Planetary Science Journal.
Meanwhile, it became clear that astronomers from France and the United States have discovered with the help of the James Webb Space Telescope that the fog in the upper layers of Pluto’s atmosphere is a major factor in the dwarf planet’s climate. The discovery may provide clues to the ancient climate of Earth, writes “Live Science”.
Pluto’s fog is composed of complex organic molecules formed as a result of reactions of methane and nitrogen under the influence of sunlight. The idea that it could control Pluto’s climate was first proposed in 2017.
Computer models have shown that these particles absorb sunlight during the day and radiate it back into space as infrared energy at night, cooling the atmosphere much more effectively than gases alone. This could also explain why Pluto’s upper atmosphere is about minus 203 degrees Celsius, or 30 degrees colder than expected.
Illustrative photo: pexels-frank-cone-140140-4233216
