I remember reading this before and thinking, if this is so obvious how come life doesn't exist on any other planets we know of?
The criteria in the article were input energy and a "bath" into which that energy can be dissipated. Perhaps there is a minimum potential difference before structures will self-organize--or perhaps the probability of self-organization is proportional to the difference.
Speculating along this line of reasoning: On Mercury, you have plenty of input energy, but few options for dissipating it. On Europa, you may have the reverse problem.
For all we know, however, Europa may actually have life. Our sample set is too small.
They are stable, emit heat and replicate ...
http://en.wikipedia.org/wiki/Sara_Seager#Seager_equation
http://en.wikipedia.org/wiki/Drake_equationPerhaps the Earth biosphere is the only "open" system in the Universe that keeps its entropy low by increasing the entropy of its surroundings, i.e. the rest of the Universe.