April 30, 2024

Scientists Identify a Possible Source for Red Cap on Pluto’s Largest Moon Charon

Charon is the biggest of Plutos moons. At half the size of Pluto, it is the largest known satellite relative to its parent body. Charon orbits Pluto every 6.4 Earth days. James Christy and Robert Harrington discovered Charon in 1978 at the U.S. Naval Observatory in Flagstaff, Arizona.

Southwest Research Institute researchers combined data from NASAs New Horizons objective with unique lab experiments and exospheric modeling to expose the likely structure of the red cap on Plutos moon Charon and how it might have formed. New findings recommend extreme seasonal surges in Charons thin atmosphere integrated with light breaking down the condensing methane frost may be essential to understanding the origins of Charons red polar zones. Charon is the biggest of Plutos moons. Soon after the 2015 encounter, New Horizons scientists proposed that a reddish “tholin-like” material at Charons pole could be synthesized by ultraviolet light breaking down methane particles. “Ethane is less volatile than methane and stays frozen to Charons surface long after spring dawn.

” Prior to New Horizons, the best Hubble images of Pluto exposed only a fuzzy blob of reflected light,” stated SwRIs Randy Gladstone, a member of the New Horizons science group. “In addition to all the interesting features discovered on Plutos surface, the flyby exposed an uncommon feature on Charon, an unexpected red cap fixated its north pole.”
Soon after the 2015 encounter, New Horizons researchers proposed that a reddish “tholin-like” material at Charons pole might be synthesized by ultraviolet light breaking down methane particles. These are captured after getting away from Pluto and after that frozen onto the moons polar areas throughout their long winter season nights. Tholins are sticky organic residues formed by chain reactions powered by light, in this case the Lyman-alpha ultraviolet radiance scattered by interplanetary hydrogen atoms.
” Our findings suggest that extreme seasonal rises in Charons thin environment as well as light breaking down the condensing methane frost are essential to comprehending the origins of Charons red polar zone,” stated SwRIs Dr. Ujjwal Raut, lead author of a paper entitled “Charons Refractory Factory” in the journal Science Advances. “This is one of the most illustrative and plain examples of surface-atmospheric interactions so far observed at a planetary body.”
The team reasonably duplicated Charon surface area conditions at SwRIs new Center for Laboratory Astrophysics and Space Science Experiments (CLASSE) to determine the structure and color of hydrocarbons produced on Charons winter hemisphere as methane freezes below the Lyman-alpha glow. The team fed the measurements into a brand-new atmospheric model of Charon to show methane breaking down into residue on Charons north polar spot.
” Our teams novel vibrant photolysis experiments supplied brand-new limitations on the contribution of interplanetary Lyman-alpha to the synthesis of Charons red product,” Raut said. “Our experiment condensed methane in an ultra-high vacuum chamber under exposure to Lyman-alpha photons to reproduce with high fidelity the conditions at Charons poles.”
SwRI researchers also developed a new computer system simulation to design Charons thin methane atmosphere..
” The design points to explosive seasonal pulsations in Charons environment due to severe shifts in conditions over Plutos long journey around the Sun,” stated Dr. Ben Teolis, lead author of a related paper entitled “Extreme Exospheric Dynamics at Charon: Implications for the Red Spot” in Geophysical Research Letters.
The team input the arise from SwRIs ultra-realistic experiments into the climatic design to estimate the distribution of intricate hydrocarbons emerging from methane decay under the impact of ultraviolet light. The model has polar zones mainly creating ethane, a colorless material that does not add to a reddish color.
” We believe ionizing radiation from the solar wind disintegrates the Lyman-alpha-cooked polar frost to manufacture significantly intricate, redder materials accountable for the special albedo on this enigmatic moon,” Raut stated. “Ethane is less volatile than methane and remains adhered Charons surface area long after spring daybreak. Exposure to the solar wind might convert ethane into relentless reddish surface deposits adding to Charons red cap.”.
” The group is set to investigate the role of solar wind in the development of the red pole,” stated SwRIs Dr. Josh Kammer, who protected continued support from NASAs New Frontier Data Analysis Program.
Recommendation: “Extreme Exospheric Dynamics at Charon: Implications for the Red Spot” by Ben Teolis, Ujjwal Raut, Joshua A. Kammer, Caleb J. Gimar, Carly J. A. Howett, G. Randall Gladstone and Kurt D. Retherford, 15 April 2022, Geophysical Research Letters.DOI: 10.1029/ 2021GL097580.

Southwest Research Institute scientists integrated data from NASAs New Horizons objective with unique laboratory experiments and exospheric modeling to reveal the likely structure of the red cap on Plutos moon Charon and how it might have formed. New findings suggest extreme seasonal rises in Charons thin environment combined with light breaking down the condensing methane frost might be crucial to understanding the origins of Charons red polar zones. Credit: Courtesy NASA/ Johns Hopkins APL/ SwRI
Research study combined spacecraft data with brand-new laboratory experiments, models of Plutos biggest moon.
Southwest Research Institute scientists integrated information from NASAs New Horizons mission with novel lab experiments and exospheric modeling to expose the most likely structure of the red cap on Plutos moon Charon and how it may have formed. This first-ever description of Charons vibrant methane environment using brand-new speculative information supplies an interesting peek into the origins of this moons red spot as explained in two recent papers.