back to article Space boffins: Exoplanet survived hydrogen-death of its host star

Those of us fatalistically counting down the minutes until the Earth is engulfed by the dying embers of the Sun in approximately 5 billion years might be offered a glimmer of hope by the news that planets – or at least gas giants – can survive the collapse of their host star. Joshua Blackman, a postdoctoral researcher at …

  1. KarMann Silver badge
    Boffin

    Other options

    …will need to hope we have in the meantime figured out how to also live on an inhospitable gas giant with a gravitational force 2.5 times that of Earth.
    Or one or more of its moons, more likely, assuming they could survive along with their parent planet. The giant phase might thaw out Europa or Ganymede quite nicely.

    1. DS999 Silver badge

      Re: Other options

      Or in orbit around one of the gas giants.

      If some sort of descendant of humanity still exists in a few billion years but somehow hasn't managed to get to other stars, one would hope we can at least build a decent leak-free space station by then.

    2. AVR

      Re: Other options

      While the gas giant survived there's a decent chance that it's smaller now - novas might not have destroyed it but they could strip off a chunk of the atmosphere.

      It's likely to be a bit chilly there once the star stopped bothering with fusion and turned into a white dwarf tho'.

      1. Tom 7

        Re: Other options

        We might have fusion sorted by then.

        Just.

        1. JDPower666
          Trollface

          Re: Other options

          Nonsense, fusion is only ten years away

          1. Loyal Commenter Silver badge

            Re: Other options

            I thought it was 20 years away? Has it gone down to ten in the last 30?

            1. JDPower666
              Trollface

              Re: Other options

              You need some better bullshit sources, mine have been telling me it's ten years for as long as I've known them and never once wavered from that view.

        2. DS999 Silver badge

          Re: Other options

          Not only would fossil fuels and uranium, thorium, etc. have run out long ago, the feedstock for all types of fusion would have as well, at least on Earth and the Moon. I mean, we're talking billions of years here, and its safe to assume our energy needs would be increasing for a good portion of that time. If Jupiter's clouds aren't blown away I'm sure there's plenty of fuel in there if we had to go back to fusion.

          But due to running out of everything that relied on "fuel" of some type, we'd not only have some amazingly efficient solar panels by then, but some damn good storage (battery, hypercapacitors, whatever) as well. With a much larger sun there would be more power to collect at any given distance so that would give us a few billion more years to figure out how to get to another star before the sun's output started to fall precipitously.

    3. Kane
      Alien

      Re: Other options

      "The giant phase might thaw out Europa or Ganymede quite nicely."

      ALL THESE WORLDS ARE YOURS.

      EXCEPT EUROPA.

      ATTEMPT NO LANDING THERE.

  2. Yet Another Anonymous coward Silver badge

    "Survived"

    I bet it made a bit of a mess though.

    Definitely affected property values

  3. Timbo

    No way to get solar energy by then...

    so, hopefully, inhabitants of Jovian moons will, by the time of a post-giant stage Sun, be able to find our sources of? (as the Sun will be too dim and still too far away to be producing as much it does currrently).

    Perhaps by then, humans (or our evolved homo-superiors) might be able to use the gravitational forces on the moon, caused by the orbit of the Jovian moon around it's parent?

    Or maybe spacecraft will be sent to Jupiter on "Hydrogen farming" trips, bringing back lots of H (as it makes up about 90% of the Jovian atmosphere) to use to produce water and energy?

    1. bombastic bob Silver badge
      Devil

      Re: No way to get solar energy by then...

      some time in the next billion years or so I think we'll just move to a different neighborhood. How long does terraforming take... ?

      So far all of the speculations about "how many stars have planets" (before exoplanets were discovered, anyway) lowball reality by a significant amount. With current models, most (if not nearly all) stars have planets (including this white dwarf system). The next guesstimate, "how many can support earth life", suggests there are a LOT of potential new planets to discover and visit in the next billion years [and maybe terraform and live there] long before Sol runs out of gas.

      within a couple of centuries it might be practical to use starships with fusion-based impulse engines, that can harvest liquified gasses from gas giants to spew out the tailpipe (you need mass more than velocity with an impulse engine for any kind of thrust efficiency) and accelerate to a high enough fraction of C so that the astronauts don't have to breed to keep the mission going... and a 100 year "earth time" mission becomes more reasonable, at least until FTL is invented at any rate.

      1. John Brown (no body) Silver badge

        Re: No way to get solar energy by then...

        "some time in the next billion years or so I think we'll just move to a different neighborhood. How long does terraforming take... ?"

        If some version of humanity is still around in a few billion years, why bother with terraforming? They'll probably be all over the galaxy by then, and/or either just stop the sun expanding by re-fueling it or just move the whole frickin' plant Earth (for sentimental reason, obviously) to a younger star.

        Hey, if we're theorising future tech, why not think big, eh?

      2. Timbo

        Re: No way to get solar energy by then...

        "some time in the next billion years or so I think we'll just move to a different neighborhood."

        The problem is getting to a different neighbourhood, even if it is just a stepping stone to further "planetary systems" that orbit hopefully newer stars.

        The nearest star (outside the Solar System) is about 4.3 light years away and given we cannot go faster that the SOL, (we cannot even get close to a tenth, a hundredth, a thousandth of SOL**), so journeying to the nearest star is probably beyond human capability and will be for a considerable time. And if there are no "stopping off points between the Sun and Alpha Centauri system, then humans cannot play "leap-frog" from planet to planet.

        **

        SOL is 299,792 km/second.

        Earths fastest spaceship, the Parker Solar Probe, has now achieved a speed of 532,000 km/h or about 148 km/second - which is 2028 times SLOWER than SOL.

        So, to get to the nearest Alpha Centauri system, using a similar craft, would take more than 2,028 times longer than if we could travel at the SOL - so, it would take about 8,723 years.

        Hopefully, in future eons, homo-superior can bend space/time or develop some form of tech to get closer to the SOL....but it'll be long after I and any fellow readers of this august website have passed on :-(

        1. Anonymous Coward
          Anonymous Coward

          Re: No way to get solar energy by then...

          "Hopefully, in future eons, homo-superior can bend space/time or develop some form of tech to get closer to the SOL....but it'll be long after I and any fellow readers of this august website have passed on :-("

          Or do away with these short-lived meatbag bodies in favour of something durable. If our successors live millions of years, speed becomes less of an issue.

        2. John Brown (no body) Silver badge

          Re: No way to get solar energy by then...

          Well, who knows what could happen acroess the relevant time period of "billions of year". Humanity went from the first powered flight to jet aircraft and rockets capable of reaching space in only 40 years.

          1. druck Silver badge
            Unhappy

            Re: No way to get solar energy by then...

            And less than 40 years from man standing on another celestial body to Facebook - I'm afraid we've already peaked.

            1. ThatOne Silver badge

              Re: No way to get solar energy by then...

              > I'm afraid we've already peaked

              Definitely already peaked!

              Besides, if you take a look at geological time scales, you can't but notice that life is rather short-lived, and that most evolutionary paths don't last more than a couple million years, at best.

              By the time our sun starts acting up (5 billion years from now), the fleeting occurrence of the human species will be older than the creation of Earth is today (4.5 billion years)...

              Sorry, there is absolutely no chance humanity might still exist by then. It's even extremely unlikely mammals as such might still be around, and that's assuming no big catastrophe (like a meteor, or a snowball earth, or a runaway greenhouse effect turning Earth into Venus) ever happens: Just plain, smooth sailing in an ever-hospitable environment. If there is still life on Earth by then, it will certainly be totally different to what we know today, more different than today's humans are to Trilobites, which reigned over Earth just a short 500 million years ago. Scale, always be aware of scale.

              1. Anonymous Coward
                Anonymous Coward

                Re: no chance humanity might still exist by then

                Well, some vaguely intelligent evolutionary descendant will have to do as our proxy then.

                .

                Because maybe some instance of homo habilis once looked at the moon and wondered ...

                ... so that then when we invent time-travel we can go back and explain facebook to them instead :-)

        3. Anonymous Coward
          Anonymous Coward

          Re: No way to get solar energy by then...

          I think the suggestion was to move the earth itself to a new solar system.

          As long as we could live on the heat stored inside the earth for 8,000 years (a blink of the eye in earth history), and continue to breed, surely it doesn't matter if it takes that long to reach the next star?

          Obviously, accelerating the entire earth to that speed would be quite an undertaking. We may have to throw off quite a lot of mass to achieve it.

          1. Anonymous Coward
            Anonymous Coward

            Re: No way to get solar energy by then...

            Or we could burn it for propulsion instead of throwing it away...

        4. Loyal Commenter Silver badge

          Re: No way to get solar energy by then...

          As you start to get to an appreciable fraction of "SOL" (or C as it's normally referred to), relativistic effects start to come into play, and those hundreds of years only apply to outside observers. Time will pass much more slowly for the inhabitants of such a ship.

          Of course, not dying of old age is not the principle problem with travelling at relativistic speeds. Not being annihilated by collisions with tiny specks of dust becomes much more important.

    2. Loyal Commenter Silver badge

      Re: No way to get solar energy by then...

      Or maybe spacecraft will be sent to Jupiter on "Hydrogen farming" trips, bringing back lots of H (as it makes up about 90% of the Jovian atmosphere) to use to produce water and energy?

      Not to be a party pooper, but the amount of energy needed to bring that hydrogen back to Earth from Jupiter is a fair bit more than you'd be getting from burning it to get water. Unless, you meant using it to make water for a Jovian colony, in which case, where's the oxygen coming from? Are you bringing that for Earth? Since it's 89% of the mass of the water you'd get from using it to burn that hydrogen, it'd probably just be more efficient to bring water. Or indeed using any of the plentiful water that there is on Jovian moons to start with, some of which are pretty much entirely ice. Just not Europa, right, attempt no landing there, etc.

  4. Chris G

    Evolved homo-superior

    There is no guarantee that evolution will result in anything superior, only that whatever survives is fit for its environment.

    Looking at the current social media infested environment and the eloquence of some of the vaccine protesters, I can only assume that in order to survive in such a situation requires retrogression. Or, perhaps nature is considering a new start?

    Cats seem to be taking over the internet, maybe they are the next dominant species.

    1. The_Idiot

      Re: Evolved homo-superior

      "Cats... maybe they are the next dominant species."

      Er - next? Let's see:

      I work. My cat sleeps, and pesters me for food.

      I go to the store. My cat plays with her toys, sleeps, and pesters me for food.

      I pay taxes. And the mortgage. My cat - well, I think you can see the pattern. _Next_ dominant species? Humans weren't ever _in_ that race, never mind winning (blush).

      1. Yet Another Anonymous coward Silver badge

        Re: Evolved homo-superior

        Cat

        Wife

        Dog

        Husband (possibly tied with Macbook)

      2. CrazyOldCatMan Silver badge

        Re: Evolved homo-superior

        I go to the store. My cat plays with her toys, sleeps, and pesters me for food

        Now scale that up with an extra 5 cats.. Although, my lot are pretty good at not demanding *too* much of my time as long as appropriate respect[1] has been paid to their whims.

        (used to be 7 cats. Sadly, the airhead one, having already been rebuilt with a pelvis held together with titanium after one cat/car interaction, decided to have another one. Sadly, this time it was the head end..)

        [1] Particularly in the form of cat treats. Great for socialising cats as they come into the household but it does doom you to maintaining the treat routine for the rest of time.

    2. Giles C Silver badge

      Re: Evolved homo-superior

      Have a look of Netflix for the series “love death and robots” then the episode “three robots”

      The other episodes are good but this is more relevant

      1. Kane

        Re: Evolved homo-superior

        You've seen one post-apocalyptic city, you've seen them all.

  5. Anonymous Coward
    Anonymous Coward

    Humanity’s future…

    Steady on now there Ted

    We’ve got to survive Trump 2.0 first….

  6. Boris the Cockroach Silver badge

    4.5 billion years?

    more like about 1.2 billion years

    thats when the suns output will have risen far enough to give a global average temp of 70 degrees C... at which point it stops raining anywhere on the planet(even at Lords cricket ground)

    For the next couple of 1000 yrs the oceans evaporate and we end up with a rather dense steamy atmosphere...... but of course CO2 is still being pumped out by volcanos and with nothing to wash it out..........

    How does 120 bar pressure and 600 degree C at the surface sound in 1.5 billion years time ? and the sun's out put is STILL rising

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