New findings suggest drastic seasonal surges in Charon’s thin atmosphere combined with light breaking down the condensing methane frost may be key to understanding the origins of Charon’s red polar zones.

This first-ever description of Charon’s dynamic methane atmosphere using new experimental data provides a fascinating glimpse into the origins of this moon’s red spot as described in two recent papers.

“In addition to all the fascinating features discovered on Pluto’s surface, the flyby revealed an unusual feature on Charon, a surprising red cap centered on its north pole.”.

Soon after the 2015 encounter, New Horizons scientists proposed that a reddish “tholin-like” material at Charon’s pole could be synthesized by ultraviolet light breaking down methane molecules.

“Our findings indicate that drastic seasonal surges in Charon’s thin atmosphere, as well as light breaking down the condensing methane frost, are key to understanding the origins of Charon’s red polar zone,” said SwRI’s Dr.

The team realistically replicated Charon surface conditions at SwRI’s new Center for Laboratory Astrophysics and Space Science Experiments (CLASSE) to measure the composition and color of hydrocarbons produced on Charon’s winter hemisphere as methane freezes beneath the Lyman-alpha glow.

The team fed the measurements into a new atmospheric model of Charon to show methane breaking down into residue on Charon’s north polar spot.

SwRI scientists also developed a new computer simulation to model Charon’s thin methane atmosphere. .

“The model points to ‘explosive’ seasonal pulsations in Charon’s atmosphere due to extreme shifts in conditions over Pluto’s long journey around the Sun,” said Dr.

The model has polar zones primarily generating ethane, a colorless material that does not contribute to a reddish color.

“Ethane is less volatile than methane and stays frozen to Charon’s surface long after spring sunrise.

June 19, 2022

June 18, 2022

June 18, 2022