brightness of the surface immediately before sunset compared to that at sunrise may
provide some additional constraints.
3.4.7 The Initial Gas Temperature
In a previous section, the porosity of the surface layer was discussed and the
influence of a desiccated, partially insulating, porous layer on the gas production
rate was calculated from the perspective of the thermal conductivity. The effect of
radiation and gas flow through the layer on the thermal conductivity of the layer was
also shown to be rather complex. However, the flow through a porous surface layer
can influence the gas properties in other ways.
Fig. 3.35 Image of 67P acquired on 29 June 2015 at 10:26:19. Notice at the edges of the shadows
(marked
by
arrows),
the
surface
is
relatively
bright.
(Image
number:
N20150629T102619565ID10F24)
3.4 Gas Expansion
243
provide some additional constraints.
3.4.7 The Initial Gas Temperature
In a previous section, the porosity of the surface layer was discussed and the
influence of a desiccated, partially insulating, porous layer on the gas production
rate was calculated from the perspective of the thermal conductivity. The effect of
radiation and gas flow through the layer on the thermal conductivity of the layer was
also shown to be rather complex. However, the flow through a porous surface layer
can influence the gas properties in other ways.
Fig. 3.35 Image of 67P acquired on 29 June 2015 at 10:26:19. Notice at the edges of the shadows
(marked
by
arrows),
the
surface
is
relatively
bright.
(Image
number:
N20150629T102619565ID10F24)
3.4 Gas Expansion
243