Development of celestial models if Earth orbited gas giant?

[Adam Reynolds]

I was just contemplating this idea after landing on Laythe in Kerbal. How would the model of the solar system change if humanity had evolved Earthlike world that orbited a much larger celestial body? I mean that in the context of whether people would realize that we orbited something else earlier. That could eventually lead to a heliocentric model coming into wide acceptance sooner than occurred historically.

Another interesting possibility is that it could lead to religions assuming that the larger body was in some way equivalent to heaven or the pantheon.

Though I wonder if complex intelligent life would even evolve on a world like that.

[SpottedKitty]

Though I wonder if complex intelligent life would even evolve on a world like that.

The most obvious showstopper would probably be the local radiation environment. Taking Jupiter as an example, there's a massively powerful radiation belt that covers at least a couple of the Galilean satellites. I think Saturn has a less intense, but still dangerous, belt. Any otherwise habitable planet that happens to be in a belt like that might not be capable of supporting the evolution of complex life on a long-term basis.

[Eternal_Freedom]

Ignoring the radiation belt issue for the moment, I doubt this Earthlike planet orbiting a gas giant would create an earlier heliocentric model. It would probably start with a geocentric model, dominated by the fuckoff-huge gas giant in the sky. Then as astronomy improved, it would switch to a gas-giant-centric model as an intermediary step. This would also depend on whether the planet is tidally locked tot he gas giant (as is the case for Io and Europa around Jupiter for instance).

For example, in the far-future epilogue to 2010 Odyssey Two, Clarke describes the Europans as believing Jupiter/Lucifer to be the dominant object in the universe, while Sol (the "Cold Sun") is thought to be Lucifer's exiled brother who marches across the skies on the dark side for ever for some past crime.

[jwl]

One question is whether there would be as much interest in stellar astronomy in that world to start with. I mean, interest in astronomy was kicked off at first by astrology, but might astrology be more focussed on the behaviour of the gas giant than the stars in such a world? Also, might the brightness of the gas giant in the sky make naked eye astronomy more difficult?

[SpottedKitty]

Also, might the brightness of the gas giant in the sky make naked eye astronomy more difficult?

That's a good point; but remember, pretty much anything in orbit round a gas giant is going to end up tidally locked, so at the least you're going to have a dark(ish) sky hemisphere and a great-huge-bright-thing-staring-back-at-me hemisphere. Add in the slow "days" from the sun going down once every revolution around the giant, and skies dark enough for astronomy are perfectly feasible.

[FireNexus]

Would earth's magnetic field be sufficient to block jupiter's radiation belt? Or would the tidal locking stop the dynamo that powers it in the first place?

[Zixinus]

They would think that the other planet was the home of the Gods and Heaven. At best, the idea that the planet we are on is the centre of the universe will be not as obvious. They'd still need to make the conclusion that the Heaven-planet is orbiting the Sun and not the other way around.

But it wouldn't matter that much in the long term. Switching to heliocentric worldview is significant in scientific history but came relatively easily if you think about it. A few people's observation and data was enough to convince everyone once the idea got around.

[SpottedKitty]

Would earth's magnetic field be sufficient to block jupiter's radiation belt? Or would the tidal locking stop the dynamo that powers it in the first place?

The field wouldn't completely vanish, because even a tidally locked Earth would still be rotating — once for each turn around Jupiter. Field strength would go way down, though, and I'd rather not be on Earth if you're going to test that it would hold against the radiation belts.

That brings up an interesting thought, though. If the rotation rate (and power of the core dynamo) is so low, would that affect other things that might or might not be important to Life As We Know It? Things like core heat, how much heat gets up to the mantle and crust, how much (or even if there will be) continental drift and surface recycling.