© Lloyd, Charles Chandler

 

MARS HEAT LOSS
"A cooling Martian magma ocean could have cooled through almost entirely to the solidus within thousands to several million years."13

MOON HEAT LOSS
"Heat loss from the Moon prior to formation of the conductive flotation lid is extremely rapid. Solidification of the first 80% by volume of the magma ocean... requires only on the order of 1000 years. As soon as a conductive lid is established on the body solidification slows greatly, and the remaining 20% by volume of the magma ocean requires about 10 million years to solidify in this reference model." "Thus, during the greatest majority of cooling, the Moon consists of a largely solid sphere with a solid conductive lid, and only a thin shell of liquid and crystals between."5

MORE EARTH HEAT LOSS
"The upper boundary layer of the mantle is fertile enough, hot enough, and variable enough to provide the observed range of temperatures and compositions of midplate magmas, plus it is conveniently located to easily supply these." "It is usually referred to as 'asthenosphere' and erroneously thought of as simply part of the well-mixed 'convecting mantle'." "Mantle potential temperature at depth under the central Pacific, and elsewhere, may be ~200 degrees C higher, without deep mantle plume input, than near spreading ridges."1

"Today there is an intrinsic temperature difference of 1000-2000 K across the D" layer separating the adiabatic portion of the lower mantle from the outer core." "The core now has a +1000 K of superheat (potential temperature relative to surface melting temperature), whereas the present day mantle has far less superheat. In other words, the present day thermal disequilibrium of the core and mantle is about as great as their chemical disequilibrium was during Earth formation, in spite of the fact that chemical diffusion is far slower than thermal diffusion. The present day superheat of the core could be a consequence of heat sources in the core. Possible heat sources for superheating the core after its formation include radioactive decay of 40K, ohmic and viscous heating. However, none of these is large enough to compensate for the secular cooling of the core over time. More plausibly, core superheat is a relic of the core formation process."10