Thursday, August 25, 2011

Novel Replicator Chemistry on Super Earths

An Earth and Planetary Astrophysics paper discusses the possibility of plate tectonics and atmospheres on super-Earths (terrestrial planets bigger than Earth).

Artist's rendering of GJ1214b. The Hubble found signs of wator vapor during a transit. From

If we assume that other complex Earth-like life (based on chemical replicators that operate in aqueous solution) is likely to evolve on terrestrial planets, it seems that the more volume that planet offers for chemistry, the more likely life is to originate from there; a given super-Earth with liquid water is therefore more likely to develop complex life than a smaller terrestrial planet, and therefore assuming that complex life can expand from its world of origin, super-Earths' progeny will be disproportionately represented. If this reasoning is correct then we would do well to focus exoplanet observations seeking life signatures on super-Earths in habitable zones.

It's worth stating that truly novel replicators - i.e. ones not originating through panspermia - would be far more valuable to our understanding of evolution in the abstract, and of the behavior of complex systems - than those seeded by a common stellar cloud of expanding material of otherwise inert nucleobases.

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