The report asks two key questions:
What are absolute requirements for life? The executive summary suggests - in decreasing certainty - four principles necessary for life to develop:
- thermodynamic disequilibrium
- an environment capable of maintaining covalent bonds between carbon, hydrodgen and other atoms
- a liquid environment
- a molecular system that can support Darwinian evolution
It also appears to hedge on the third and fourth items, which leads to second question: would we - how would we - recognize such exotic life if we encountered it?