The latest observations from NASA's James Webb Space Telescope (JWST) have unveiled intriguing phenomena on Pluto's surface, including seasonal cycles of volatile ice redistribution and material transfer from its atmosphere to its moon Charon, a unique interaction not seen elsewhere in our solar system.

These extraordinary findings are outlined in a recent series of studies published by an international team of scientists. A key study, published in Nature Astronomy on June 2, validates hypotheses put forth by UC Santa Cruz's Xi Zhang concerning Pluto's atmosphere, following the historic flyby of NASA's New Horizons spacecraft in 2015.

Pluto, once considered a planet but later reclassified as a dwarf planet, has been the subject of much scientific interest. Zhang's groundbreaking 2017 paper proposed that Pluto's atmosphere is primarily composed of haze particles, a feature distinct from other planetary atmospheres. According to Zhang, these haze particles play a crucial role in regulating the energy balance in Pluto's atmosphere by heating and cooling.

Following the launch of JWST in 2021, Zhang's hypothesis was put to the test. The recent JWST study, motivated by Zhang's earlier work, confirmed the presence of strong mid-infrared radiation emitted by Pluto, supporting the notion that the haze is responsible for cooling the dwarf planet.

The observations made during the Pluto flyby in 2015 revealed a diverse landscape with complex features and a chemically rich atmosphere. Charon, Pluto's moon, was found to lack an atmosphere and displayed a surface dominated by water ice mixed with ammonia-based compounds.

The JWST data, collected in May 2023, provided unprecedented insights into the Pluto-Charon system. By analyzing the mid-infrared thermal emission from both bodies, researchers gained a better understanding of the atmospheric processes and the origin of Pluto's ices.

The JWST light curves also offered valuable information on the thermal properties of Pluto and Charon, shedding light on the global ice distribution on Pluto and the movement of atmospheric molecules to Charon. These findings have implications for our understanding of planetary atmospheres and the behavior of haze particles in extreme environments.

By studying Pluto's haze and chemistry, scientists hope to gain insights into the conditions that may have made early Earth habitable. The research team, led by scientists from the Paris Observatory and the University of Reims Champagne-Ardenne, contributed theoretical models to interpret the JWST data and analyze Pluto's atmospheric cooling rates.