Ongoing Resurfacing of KBO Eris by Volatile Transport in Local, Collisional, Sublimation Atmosphere Regime

Abstract

Kuiper belt object (KBO) Eris is exceptionally bright with a greater visible geometric albedo than any other known KBO. Its infrared reflectance spectrum is dominated by methane, which should form tholins that darken the surface on timescales much shorter than the age of the Solar System. Thus one or more ongoing processes probably maintain its brightness. Eris is predicted to have a primarily nitrogen atmosphere that is in vapor pressure equilibrium with nitrogen-ice and is collisional (not ballistic). Eris's eccentric orbit is expected to result in two atmospheric regimes: (1) a period near perihelion when the atmosphere is global (analogous to the atmospheres of Mars, Triton, and Pluto) and (2) a period near aphelion when only a local atmosphere exists near the warmest region (analogous to the atmosphere of Io). A numerical model developed to simulate Eris's thermal and volatile evolution in the local atmosphere regime is presented. The model conserves energy, mass, and momentum while maintaining vapor pressure equilibrium. It is adaptable to other local, collisional, sublimation atmospheres, which in addition to Io and Eris, may occur on several volatile-bearing KBOs. The model was applied for a limiting case where Eris is fixed at aphelion and has an initial nitrogen-ice mass everywhere equal to the precipitable column of nitrogen in Pluto's atmosphere during the New Horizons encounter (the resultant mass if the Pluto atmosphere collapsed uniformly onto the surface). The model results indicate that (1) transport of nitrogen in the local, collisional, sublimation atmosphere regime is significant, (2) changes of Eris's albedo or color from nitrogen transport may be observable, and (3) uniform collapse of a global, nitrogen atmosphere likely cannot explain Eris's anomalous albedo in the present epoch. Seasonal volatile transport remains a plausible hypothesis to explain...

arXiv commentAccepted for publication in Icarus

References in corpus (13)

• The Pluto system: Initial results from its exploration by New Horizons
• The Geology of Pluto and Charon Through the Eyes of New Horizons
• Discovery of a planetary-sized object in the scattered Kuiper belt
• Convection in a volatile nitrogen-ice-rich layer drives Pluto's geological vigor
• Structure and Composition of Pluto's atmosphere from the New Horizons Solar Ultraviolet Occultation
• Global Albedos of Pluto and Charon from LORRI New Horizons Observations
• Pluto's Seasons: New Predictions for New Horizons
• Physical Properties of Kuiper Belt and Centaur Objects: Constraints from Spitzer Space Telescope
• Methane and Nitrogen Abundances On Pluto and Eris
• Light Curves of Dwarf Plutonian Planets and other Large Kuiper Belt Objects: Their Rotations, Phase Functions and Absolute Magnitudes
• Time series photometry of the dwarf planet ERIS (2003 UB313)
• Tentative Detection of the Rotation of Eris
• A Search for Temporal Changes on Pluto and Charon

Cited by in corpus (7)

• Moderate D/H Ratios in Methane Ice on Eris and Makemake as Evidence of Hydrothermal or Metamorphic Processes in Their Interiors: Geochemical Analysis
• Photometry of Kuiper Belt Object (486958) Arrokoth from New Horizons LORRI
• Volatile evolution and atmospheres of Trans-Neptunian Objects
• Hypotheses for Triton's Plumes: New Analyses and Future Remote Sensing Tests
• Solar system Deep Time-Surveys of atmospheres, surfaces, and rings
• Thermal-orbital evolution of Eris
• Trans-Neptunian Space and the Post-Pluto Paradigm