Planetary Parameters

Brian Aldiss wrote somewhere that an sf writer works hard for his living. A contemporary novelist writes about the interactions between a cast of characters. An sf novelist - at least sometimes - devises the parameters of an extra-solar planetary system, then places a cast of characters in that environment.

Poul Anderson outlines this in his AFTERWORD to The Man Who Counts:

the mass, age and chemistry of a star

its consequent luminosity

the length of the year of a planet in a given orbit

the quantity of radiation received by that planet

surface features

the kind of life on the planet

the evolution of that life

these parameters affecting others

the odour of a flower

what it is like to be an inhabitant of that planet

This is what CS Lewis called the Engineer's Story. Not everyone who can write fiction knows enough science which is why there is some "soft" sf by Lewis, Bradbury and Simak. (Bradbury's Mars, cold by night but hot (!) by day, is an abomination.)