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If the Moon were a bigger satellite how would this impact life on Earth?

For arguments sake, what would happen if the Moon and Saturn, suddenly switched places?
Could life exist with this now larger satellite?

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    $\begingroup$ That's not just "much" larger, that's a 38,200x larger moon. $\endgroup$
    – RonJohn
    May 12, 2017 at 23:20
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    $\begingroup$ You might want to consider something smaller then the third largest object in the solar system, counting the sun! $\endgroup$ May 12, 2017 at 23:25
  • $\begingroup$ @user2448131 care to elaborate? ;) $\endgroup$
    – Recelica
    May 12, 2017 at 23:29
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    $\begingroup$ Saturn is very large. Only Jupiter and the Sun are larger. Its presence in the Earth orbital location would probably disrupt the entire inner solar system, and likely destroy earth if it was the same distance as the moon is now. Ah, see answer below. $\endgroup$ May 12, 2017 at 23:33
  • $\begingroup$ The gravitational potential energy released by Saturn moving so much closer to the sun would most likely be dissipated as heat, frying the Earth. $\endgroup$
    – Mike Scott
    May 13, 2017 at 8:40

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If the moon were bigger it might not impact earth as much as you'd think. Life would probably find a way, as it historically does.

It is entirely possible a larger moon would actually give us a more stable tilt, the angle at which heat from the sun hits it, meaning less climate change and less chances of ice age.

A moon with more gravity would slow down the Earth's spin and cause longer days (this is already happening slightly with the current moon). Depending on the size of the moon, the inhabitants would need to live during many days of darkness at a time. In the arctic circle, things survive 6 months of darkness, so I'm sure humans would figure it out.

Pluto and Charon are close in size comparatively and they are tidal-locked to each other, meaning they are always facing each other at a single point like figure skaters holding hands. There may be a side of the Earth the Moonanites never see, like we don't see the "dark side" of the Moon.

source

Saturn as a "moon" would impact life on Earth by extinguishing all of it.

Check out this super old, but awesome video.

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Well, Saturn happens to be much larger than the Earth. So large that the Earth would then be the moon, not Saturn.

Luckily Saturn's Roche Limit is about 75,000km and the distance between the Moon and the Earth is about 380,000km. So the Earth would not be torn apart right away.

However, the tidal stresses will likely greatly increase earthquakes and vulcanism. The tides would get pretty ridiculous too.

I don't know enough orbital mechanics but I suspect that our geostationary satellites will have a hard time staying in place.

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    $\begingroup$ I don't know the numbers off hand but probably tidally locked. $\endgroup$ May 12, 2017 at 23:35
  • $\begingroup$ @user2448131, I thought so but I don't know enough to state it in my answer. $\endgroup$
    – ShadoCat
    May 13, 2017 at 0:47
  • $\begingroup$ @user2448131 Don't guess, calculate and post and answer! That is how we do it here. $\endgroup$
    – kingledion
    May 13, 2017 at 11:19
  • $\begingroup$ The Roche limit depends on the size of the body to remain unbroken. From earlier answers, I suspect that the distance needed for Earth to remain intact is much greater — on the order of a million km $\endgroup$
    – JDługosz
    May 13, 2017 at 11:30
  • $\begingroup$ Note that Jupiter's moon Io is pretty close to the same distance from Jupiter as the Moon is from Earth, so we could expect some fairly serious tidal heating effects. $\endgroup$
    – jamesqf
    May 18, 2017 at 3:59

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