Finally, the aesthetic of space music tends to be dark yet warm, something like dark ambient music but without the sense of horror. A lot of space music suggests a feeling of flying through outer space with perfect freedom, somehow freed from all limitations, as if you were soaring between the stars. It's like the musical equivalent of science fiction, back when science fiction was still generally optimistic. I find it to be some of the most effective music to play during meditation, because it helps me block out external stimuli while slowly calming my heart-rate and breathing.
When I meditate while listening to space music, I usually find myself spontaneously visualizing stars and planets, galaxies, nebulae and black holes, all of which seem to flow by me as I watch them, entranced.
I was first introduced to space music through a public radio program called Hearts of Space, which now exists as an online radio station playing space music twenty-four hours a day. If you're curious about this sub-genre of New Age music, they have a sample show you can listen to for free.