Pluto's Atmosphere Thins as It Recedes, Hinting at Collapse
New Horizons data and Earth-based stellar occultations show Pluto’s atmospheric pressure rose from 1988 to 2015, stayed roughly constant until about 2021, and then declined by as much as 16% by 2022 as the dwarf planet moved farther from the Sun, potentially signaling the first signs of atmospheric collapse that had been anticipated for decades; continued observations over the coming years will be needed to confirm the trend, with Pluto not returning closer to the Sun until 2114.