Over on io9 (yes, it’s one of my favourite sites), there’s an article about a triple-star system that might have as many as four planets in the habitable zone, where water and potentially complex and stable atmospheres can exist. Gliese 667C is only 22 light years away. Only. Come on, what happened to that warp drive they were talking about last year?
Anyway, what caught my eye (other than “habitable planets”) was a description of what standing on a planet in a three-star system might be like.
From the perspective of one of its several planets, the two other stars (both of which are K-dwarfs) would look like a pair of very bright stars visible in the daytime and night. They would likely provide as much illumination as the full Moon.
It doesn’t sound like much light…until you consider that the full moon occurs only three days per month on Earth and on those nights, it can be incredibly bright. In comparison to most other nights, anyway.
So let’s think about night on one of these planets orbiting Gliese 667C, assuming the other stars are visible. Every night, barring cloud-cover, would still have a significant amount of light. How would creatures’ vision have adapted? Would there be some predators more attuned to the darkest nights, perhaps deadlier then? Would they use camouflage differently? If there were intelligent creatures on the planet, would they be more afraid of the dark, since it would be so rare, or less so?
At times like this, I wish I had degrees in all the things so I could imagine a world like this a little better.