NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
The Formation of Charon's Red Poles from Seasonally Cold-Trapped VolatilesA unique feature of Plutos large satellite Charon is its dark red northern polar cap. Similar colours on Plutos surface have been attributed to tholin-like organic macromolecules produced by energetic radiation processing of hydrocarbons. The polar location on Charon implicates the temperature extremes that result from Charons high obliquity and long seasons in the production of this material. The escape of Pluto's atmosphere provides a potential feedstock for a complex chemistry. Gas from Pluto that is transiently cold-trapped and processed at Charon's winter pole was proposed as an explanation for the dark coloration on the basis of an image of Charon's northern hemisphere, but not modelled quantitatively. Here we report images of the southern hemisphere illuminated by Pluto-shine and also images taken during the approach phase that show the northern polar cap over a range of longitudes. We model the surface thermal environment on Charon and the supply and temporary cold-trapping of material escaping from Pluto, as well as the photolytic processing of this material into more complex and less volatile molecules while cold-trapped. The model results are consistent with the proposed mechanism for producing the observed colour pattern on Charon.
Document ID
20170003179
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Grundy, W. M. (Lowell Observatory Flagstaff, AZ, United States)
Cruikshank, D. P. (NASA Ames Research Center Moffett Field, CA United States)
Gladstone, D. R. (Southwest Research Inst. San Antonio, TX, United States)
Howett, C. J. A. (Southwest Research Inst. Boulder, CO, United States)
Lauer, T. R. (National Optical Astronomy Observatories Tucson, AZ, United States)
Spencer, J. R. (Southwest Research Inst. Boulder, CO, United States)
Summers, M. E. (George Mason Univ. Fairfax, VA, United States)
Buie, M. W. (Southwest Research Inst. Boulder, CO, United States)
Earle, A. M. (Massachusetts Inst. of Tech. Cambridge, MA, United States)
Ennico, K. (NASA Ames Research Center Moffett Field, CA United States)
Parker, J. Wm. (Southwest Research Inst. Boulder, CO, United States)
Porter, S. B. (Southwest Research Inst. Boulder, CO, United States)
Singer, K. N. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Stern, S. A. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Verbiscer, A. J. (Virginia Univ. Charlottesville, VA, United States)
Beyer, R. A. (Search for Extraterrestrial Intelligence Inst. Moffett Field, CA, United States)
Binzel, R. P. (Massachusetts Inst. of Tech. Cambridge, MA, United States)
Buratti, B. J. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Cook, J. C. (Southwest Research Inst. Boulder, CO, United States)
Ore, C. M. Dalle (Search for Extraterrestrial Intelligence Inst. Moffett Field, CA, United States)
Olkin, C. B. (Search for Extraterrestrial Intelligence Inst. Moffett Field, CA, United States)
Parker, A. H. (Search for Extraterrestrial Intelligence Inst. Moffett Field, CA, United States)
Protopapa, S. (Maryland Univ. College Park, MD, United States)
Quirico, E. (Universite Grenoble Alpes Saint Martin d'Heres, France)
Moore, J. M. (NASA Ames Research Center Moffett Field, CA, United States)
Reuter, D. C. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Date Acquired
April 7, 2017
Publication Date
September 14, 2016
Publication Information
Publication: Nature
Volume: 539
Issue: 7627
ISSN: 0028-0836
Subject Category
Lunar and Planetary Science and Exploration
Report/Patent Number
GSFC-E-DAA-TN40508
Distribution Limits
Public
Copyright
Other