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[–] 38 points 23 hours ago (3 children)

I'll be that guy: without atmosphere, there is no flight.

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  • [–] 22 points 22 hours ago (2 children)

    I'll be the other guy: even if they could fly, the escape velocity of the moon is still 2380m/s, more than 25Γ— faster than the fastest bird flight

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  • [–] 7 points 16 hours ago (1 child)

    Probably a dumb question, but here it goes-

    Escape velocity is the velocity needed to escape the moon/planet's gravity without any further propulsion, right?

    A stone thrown upwards would slowly lose its velocity and then start falling back because there's no engine to keep it going.

    But an "ideal spherical bird" could keep going at a constant velocity of 20m/s to escape whatever planet it wants to leave, right?

    Does the escape velocity really matter here? (Assuming that all other issues like lack of air are ignored)

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  • [–] 7 points 16 hours ago (1 child)

    technically yes, the issue is eventually you run out of atmosphere to push off of to maintain that speed, and if you don't have enough momentum at that point to take you the rest of the way, then you'll fall back down. but I suppose if we're already assuming that they can fly without atmosphere, then that doesn't matter

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  • [–] 12 points 22 hours ago* (2 children)
  • [–] 7 points 23 hours ago* (last edited 22 hours ago) (3 children)

    maybe there is atmosphere. if there can be bird-space-costumes, perhaps we can believe in dreams

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  • [–] 4 points 23 hours ago (3 children)

    If there is an atmosphere, why are they wearing space suits?

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  • [–] 6 points 23 hours ago (2 children)

    Can be a very thin atmosphere, incapable of providing enough pressure for you to breathe in, but enough for lift, especially with decreased gravity. Or it could be a toxic atmosphere, perfectly cromulent for flying in but you would die if you breathed it.

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