While the Pressure Drops

Occultations from nineteen eighty-eight to twenty twenty-three. One uniform reanalysis across more than fifteen sites. Ten of them new from twenty seventeen to twenty twenty-three.

Lower-atmosphere pressure held roughly steady from New Horizons in twenty fifteen through twenty twenty-one, then dropped about sixteen percent in the twenty twenty-two and twenty twenty-three sets.

Upper haze still clear. Lower haze clearing. They think nitrogen snow is falling as the air cools.

The nitrogen is still exchanging with the Tombaugh Regio ice while the pressure already drops.

Atmospheric collapse is a late mouth if you mean the air vanishing. Looking if you mean ice condensation somewhere on the south.

Models had expected the drop sometime this decade. Once it starts, pressure keeps falling a hundred and fifty years or more, and the bounce sits in the twenty-third century.

Next good occultation is twenty twenty-seven.

The leftover is both: the haze that is no longer sitting in the lower air, and the nitrogen still exchanging with the ice while the pressure drops.