"Before Old Mars was terraformed during the First Commonality, archaeologists posit a 'prehistoric age of space' - before the Autumn Civilisations, the Fall of Man, and the Great Glaciation - when humankind first realised it was not alone in the cosmos. What must it have been like for those early humans, who looked up into the skies at that dim red dot with their primitive remotes, and saw there flowing water - and life?"
- Professor Mens Tertius Saganis, Inaugural Palaeogenology Lecture, Syrtis University Nepenthes Campus, 194 NCE http://io9.com/are-these-pictures-of-water-flowing-on-mars-right-now-1520115138?utm_campaign=socialflow_io9_facebook&utm_source=io9_facebook&utm_medium=socialflow
The Mindjammer setting is founded on the principle that life is an emergent property of the universe - that, given enough time and adequate chemical complexity, self-replicating systems will arise that we can recognise as life. Aqueous planets are just a subset of this - but one which we as humans find most palatable and comprehensible.
The terraforming of Old Mars was an incredible feat of geoengineering during the First Age of Space, involving the installation of gravity engines, a tidal orbital, and the genurgic development of a hybridised biosphere developed from remnant Martian life and fossil record. There's a theory that the discovery of life on Mars early in human prehistory was one of the spurs which coaxed the fledgling stellar civilisation of humankind to the stars.
I wonder if that's somewhere about now?