Heat and gas is transported within the nucleus of comets according to the so called diffusion equation. Although no gas diffusion is believed to be present below the surfaces of asteroids, the basic physical processes are very similar to those of comets.
The goal of the project is to develop a general purpose method for solving the heat and gas diffusion equation in 3-dimensional geometries, using finite element methods. The technique will be useful both for the study of the thermal physics of asteroids and the thermo chemical evolution of comets. By using finite elements methods it will be possible to study the effects of small scale surface roughness and highly irregular asteroids and cometary nuclei, without neglecting the 3-D flows of heat and gas.
A small section of the surface a rotating asteroid. To the left is the reflected solar radiation, and to the right the resulting temperature on and below the surface. Temperatures are indicated by colors from black (cold) to yellow (warm). Shadows and multiple scattering processes are considered on the rough surface, as the Sun and the thermal IR emission is heating and re-heating the surface. The volume is divided into 2058 volume elements, and the diurnal heat flow is followed for the 512 grid points within the volume.
The Uppsala planetary system group
Johan Lagerros