Subsurface Energy Storage and Transport for Solar-Powered Geysers on Triton
Abstract
The location of active geyser-like eruptions and related features close to the current subsolar latitude on Triton suggests a solar energy source for these phenomena. Solid-state greenhouse calculations have shown that sunlight can generate substantially elevated subsurface temperatures. A variety of models for the storage of solar energy in a sub-greenhouse layer and for the supply of gas and energy to a geyser are examined. "Leaky greenhouse" models with only vertical gas transport are inconsistent with the observed upper limit on geyser radius of ~1.5 kilometers. However, lateral transport of energy by gas flow in a porous N_2 layer with a block size on the order of a meter can supply the required amount of gas to a source region ~1 kilometer in radius. The decline of gas output to steady state may occur over a period comparable with the inferred active geyser lifetime of five Earth years. The required subsurface permeability may be maintained by thermal fracturing of the residual N_2 polar cap. A lower limit on geyser source radius of ~50 to 100 meters predicted by a theory of negatively buoyant jets is not readily attained.
- Publication:
-
Science
- Pub Date:
- October 1990
- DOI:
- 10.1126/science.250.4979.424
- Bibcode:
- 1990Sci...250..424K
- Keywords:
-
- Atmospheric Models;
- Geysers;
- Insolation;
- Planetary Geology;
- Solar Planetary Interactions;
- Triton;
- Gas Transport;
- Greenhouse Effect;
- Planetary Meteorology;
- Satellite Atmospheres;
- Satellite Surfaces;
- Lunar and Planetary Exploration