Comment on This Earth-sized Exoplanet is On a Death Spiral

• kichae@wanderingadventure.party ⁨11⁩ ⁨hours⁩ ago

  typotyper@sh.itjust.works said in How fast is that in kilometers per hour?: So you’re saying as our own system ages the planets will get pulled in and eaten up.

  Not in the same way, no. None of our planets are touching the Sun’s atmosphere in the same way this planet is, and none of them are orbiting at rates that are faster than the Sun’s rotation. If anything, tidal interactions would want to speed up the planet’s orbits, and push them into higher orbits.

  But eventually the Sun will become a red giant star, which will change some of these relationships. We will see competing effects then: The Sun will begin shedding its outer layers, which will create a higher drag environment for the planets (that were not swallowed during the Sun’s expansion) which would tend towards inward migration, but this will also lower the Sun’s mass, which will lend itself toward an outward migration.

  typotyper@sh.itjust.works said in How fast is that in kilometers per hour?: Would Jupiter being a gas giant get slowed down equally to the outer planets or would it eat some planets on its own.

  All of the outer planets are gas giants.

  Jupiter is not currently migrating inward, nor are any of the other planets. If inward migration happens after the Sun becomes a red giant, those other outer planets will not get anywhere close to it. As a red giant, the Sun will approximately fill Earth’s orbit. Jupiter’s orbit is 5x larger than this; Saturn’s is 10x larger, and by the time the Sun actually grows this large, all of the planets’ orbits will be even larger than they are today, thanks to gradual mass loss.

  None of the outer planets are expected to fall into the Sun at any point in time.

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  • Typotyper@sh.itjust.works ⁨9⁩ ⁨hours⁩ ago

    Thanks for the answers (and time). It’s cool to learn these things.

    I could ask another 100 questions and still not understand half of it.

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