They might not be trying to explore physical space, they might be trying to explore chemical space. Chemical space? http://pipeline.corante.com/archives/2013/04

They might not be trying to explore physical space, they might be trying to explore chemical space. Chemical space? http://pipeline.corante.com/archives/2013/04/18/a_short_peptide_and_a_small_molecule.php http://pipeline.corante.com/archives/2013/04/18/a_short_pept... Consider the question of whether there is any alternative biochemical basis for life. It is quite likely that even an alien super-intelligence finds the question impossible. Sure, it can invent synthetic biologys that are variations on its own biochemistry, but is there anything genuinely different out there? Given the size of chemical space it is probably easier to travel ten thousand light years to the nearest planet with life on it and look to see if its basis is the same or different.