The granddaddy of modern space art has to be Chelsey Bonestell. Throughout the first half of the 20th century Bonestell created stunning works of art grounded in scientific realism, yet still so fantastically awe inspiring.
The primary modern aesthetic inspired by Bonestell is called "Descriptive Realism". The fundamental guiding principle behind this kind of space art is that the majority of detail needs to have a grounding in scientific fact. For example, what color would the sky look like like if I was standing on a certain exoplanet?
This kind of "science meets art" realism has exploded in recent years as astronomical discoveries have increased. As we learn more and more about the universe we inhabit, a whole new generation of space art has arrived, guided by science and inspired by fantasy.