planetary-surface reaction layers

A useful counterpoint to organism-centricity, and in particular to the media's xenophobic focus on "aliens" from outer space, may be the idea that life (like that on earth) is to first order a fascinating steady-state reaction-layer between a planetary surface and the high-energy photon bath provided to that surface by the nearest star. Moving of that reaction off planet e.g. to a neighboring planet, to space habitats, or even to a star system elsewhere may, in that context, be much easier said than done.

The possibilities are of course certainly worth exploring. If taking care of our own planet is a leap for us, terraforming a nearby one is a bigger leap (that we may never manage unless we recognize the challenge), and the energy requirements of travel between star systems (even though relativity helps with time-elapsed for the traveler) make it hardly cost-effective for transferring organisms like us. Transfer of molecular and/or idea codes, on the other hand, e.g. over 10⁵ year time scales via radiation-pressure ejected nanoparticles or over 10 to 1000 year time scales by electromagnetic communication, may be another story.