Trans-Neptunian objects: More than meets the ice

Area of Science:

• Planetary Science
• Astronomy
• Dwarf Planet Research

Background:

• Eris (136199) is the second most massive known trans-Neptunian object.
• Understanding the thermal history and surface composition of trans-Neptunian objects is crucial for characterizing the outer solar system.
• Pluto, a well-studied dwarf planet, exhibits a different thermal and compositional profile.

Purpose of the Study:

• To investigate the early thermal evolution of Eris.
• To determine the nature of Eris's ice shell.
• To compare the internal processes of Eris and Pluto.

Main Methods:

• Analysis of observational data (e.g., thermal emission, albedo).
• Thermodynamic modeling of ice shell evolution.
• Comparative planetology with Pluto.

Main Results:

• Evidence suggests Eris experienced significant internal heating and melting early in its history.
• Eris maintains a warm, conductive ice shell, likely composed of materials facilitating heat transfer.
• The ice shell of Eris is distinct from the predominantly insulating ice shell inferred for Pluto.

Conclusions:

• Eris's early melting and warm ice shell indicate unique internal heat sources or different formation conditions compared to Pluto.
• The conductive nature of Eris's ice shell may influence its surface activity and interaction with the space environment.
• Comparative studies of Eris and Pluto provide key insights into the diversity of dwarf planets.