Comments by "Angry Kittens" (@AngryKittens) on "Venus 101 | National Geographic" video.

As the sun expands, yes. Though Mars is not the likely candidate for the next life-supporting planet. The more likely candidate is Jupiter and Saturn themselves as their atmospheres are blown off by solar wind, revealing their rocky cores. There's even a term for these: chthonian planets. Their advantage of course is that both have magnetospheres protecting them from radiation. Mars has no magnetosphere, which means it's being constantly bombarded by radiation which prevents the formation of complex molecules and thus surface life. No magnetosphere also means it is still bleeding out its atmosphere as it takes the full force of the solar wind. By the time Earth becomes uninhabitable, Mars will have no atmosphere left and will be truly a dead world. It would be more similar to Mercury now.
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@Justin Media They probably won't. The mechanism is called hydrodynamic escape. But it requires that Jupiter and Saturn be very close to the sun, which is unlikely to happen even in the red giant phase. Just saying they're more likely candidates than Mars. Their moons are also other candidates. Then again, they routinely pass within the deadly radiation belts of Jupiter and Saturn, so nah. They can become Earth-like though, but probably will never develop or support life. No, we can not bring back Mars' magnetosphere, short of god-like technology that could melt the outer core.
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@m_i_g_5108 An "immense inflated rugged tire"? LOL. I'd like to smack whoever taught your science class. You think gas giants are just made if puffy clouds that spaceships can fly straight through? The term "gas", "rocky", and "ice" planet refers to their element composition, NOT the phase of matter they are in. Gas giants (Jupiter, Staurn) are called gas giants because they are mostly composed of hydrogen and helium. Rocky planets (Earth, Venus, Mars, etc.) are called rocky planets because they are composed mostly of metals and silicates. Ice giants (Uranus, Neptune) are called ice giants because they mainly composed of water, methane, or ammonia. But here's the thing: most of the hydrogen and helium on gas giants are under so much extreme pressure that they are actually mostly in the supercritical fluid state. Neither gas nor liquid. And deeper down is a solid core. Without which planets (or stars) would not be able to form in the first place. That core is the "seed" or "embryo" formed by clumps of dust (planetesimals) that grow larger by colliding and sticking with other clumps (accretion). ALL planets begin this way, and thus all planets have cores. Jupiter is not a giant helium balloon.
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@3kvintageop126 @dAhYuNs BiBiMbAp Did you both even read what I wrote? Again: chthonic planets. Find out what that is. It baffles me how so many people believe gas giants are made of nothing but wispy gas clouds.
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@helios9947 I did already say that too. It all depends on whether their magnetospheres falter for some reason and how close they actually get to the dying sun. The solar wind on a red giant will be much stronger after all. They'll also be orbiting closer (and even closer still if they migrate inwards) and may become tidally locked. Jupiter and Saturn's moons, however, will be within the next habitable zone, at least for a few billion years. Mars, like all inner planets, will be too close to the Sun to survive.
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@MikeGSK Judging by the number of them, I think a science curriculum in a particular country has been teaching kids that gas giants are "made up of gas." Which is just frustrating to be honest.
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