I’ve heard people trying to tell me that a day on the moon Pandora would be like an average day like ours. But since it’s a moon around a planet with size comparison to Saturn, wouldn’t it have an irregular day compared to ours?

  • What would a day be like on Pandora when it’s orbiting around an actual planetary body?

Moon Pandora next to its planet

  • 4
    This seems like it's better suited for Space Exploration or Physics using an actual moon of Saturn has the basis instead of pandora.
    – Edlothiad
    May 23, 2018 at 19:50
  • @Edlothiad so if I copyed and pasted it into that one do you think I’d get labeled as “duplicating”? I also thought that it’s a mythical planet/ moon not a real one so within the SF realm about planet/ moon not a real one. This is about a planet within a movie not a documentary or based off of an actual planet. I hope that explains my thinking to you about how this question fits within this particular sci-fi site.
    – K.Lanie
    May 23, 2018 at 20:08
  • You could also try World Building - worldbuilding.stackexchange.com/questions/98909/…
    – Jontia
    May 23, 2018 at 20:09
  • @K.Lanie You can copy and paste a question between sites, provided you delete it on the original site. It's usually far better to tailor your question to the site where it's asked - e.g. ask about information available in sci-fi canon for Science Fiction & Fantasy, but talk more about the physical properties of the astronomical bodies for Astronomy or Worldbuilding. For the record, I think this question could be on-topic here if you edit it to be more like "what IS a day like on Pandora?" (sci-fi info) rather than "what WOULD a day be like on [a moon like] Pandora?" (astronomy info).
    – Rand al'Thor
    May 23, 2018 at 20:36

1 Answer 1


The Avatar: The Game included significant detail about Pandora and the Alpha Centauri system that wasn't included in the film, notably that the 'day-night cycle' is highly variable and that nighttime on Pandora can be almost (10%) as bright as daytime depending on its orbital position.

The absence of discussion of Pandora's actual day/night length tends to suggest that it's about the same as Earth (i.e. approximately 12 hours of day and 12 hours of night, depending on the season).

Pandora receives significant light from Alpha Centauri B (ACB). Because of this, for half the Polyphemian year its nights are never dark, but instead are more like Earthly dusk. At the closest point in its orbit, ACB is about 2,300 times as bright as Earth's full moon; at its farthest, it is still one hundred and seventy times as bright. During the other half of the year, when ACB is in the daytime sky, many Pandoran nights are illuminated both by Polyphemus's huge disk and reflected light from other nearby moons. Truly dark nights are uncommon. Polyphemus occasionally eclipses ACB at night for about one hundred minutes, but the light reflected by the planet still keeps the night from being dark. When ACB shares the daytime sky with ACA, at its closest it adds about half a percent to the total illumination. When the 2 stars are close together in the sky, the effect of ACB's more orange light is unnoticeable, but as they separate over the years, an orange tint may be seen in areas shadowed from ACA's direct illumination. At its most distant, ACB is about 2,700 times dimmer than ACA and does not produce noticeable lighting effects. However, it still appears as a blindingly-bright tiny orange disk in the sky.

Because of its high axial tilt (29 degrees), Pandora exhibits considerable annual variation in the day-to-night ratio. In addition, its elliptical orbit produces seasonal temperature variations and a range in daytime illumination of about ten percent.

  • I appreciate you answering this my friend. I also pressed up for you as well as accepting your answer
    – K.Lanie
    May 23, 2018 at 20:57

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