One thing that isn’t too often thought about regarding the end of the earth is that getting baked or even swallowed by the sun are not the only possibilities.
In previous articles, I’ve read of the possibilities of what we might do to prevent earth’s end billions of years from now if we’re still around.
But if we aren’t, or choose not to save the earth, there is one possibility that has a particularly interesting potential outcome in the far future.
In a 2000 paper by Greg Laughlin and Fred C. Adams report that there is a chance, albeit a diminishing small one, that a passing star could gravitationally disrupt the solar system enough to eject earth out of the solar system entirely.
That stars will pass close by in the future is a given, but the further into the distant future we try to predict the harder it becomes to determine which stars will pass by and what effects they may have gravitationally.
Stellar events of billions of years from now are essentially impossible to predict.
And there are a lot of other variables, for example, the authors note that a binary star system would disrupt things more than a single star system, and distance plays a prominent role. But, nevertheless, they calculated that it could happen before the runaway greenhouse effect starts due to the brightening of the sun as it ages.
There are two scenarios if earth exits the solar system if a star passes too close. One is that it could be flung into deep space where its surface will freeze solid. That would be the end of the surface biosphere of the earth if it’s still around, but geothermal vents would persist in the oceans and life might just endure on, at least as long there is enough radioactive decay in the planet’s core to keep things warm.
But there is another possibility.
Again, while the chances are very low, the earth could get captured by the passing star and begin life anew.
The odds would be beyond reasonable that we might end up in a habitable zone and the act of migration alone would probably kill most surface and ocean life, but the microbes might survive it at their vents and life that originated in this solar system may end in another.
On the other hand, we could just as easily get unlucky and end up with a star that just happens to be preparing to explode.
But then again, if we’re still around, we might survive it using fission, fusion or geothermal technology.
I would direct the interested to Greg Laughlin’s blog. In that, he notes that we would have tens of thousands of years of warning that the star would be coming. With proper planning, we might survive it and maybe even direct the process.
If we’re not here, perhaps some far future civilization may someday come across rogue planet earth and thaw it out, and with any luck their Astro-archeologists might find evidence of us, perhaps what used to be a plastic water bottle preserved in a fossil layer, though the longer the time that ensues, the less evidence there will be for them to find.
But that’s a topic for a future article, detecting dead civilizations including our own, should we go extinct. I find that topic interesting, but somewhat sad, I would hope that whatever civilizations we might find in our universe are alive, well and friendly.
I hope they find us in similarly good condition. But If we survive our infancy and become a far-flung space-faring civilization, maybe we’ll run across someone else’s ex-world from long ago wandering the cosmos as a rogue planet.
As an aside, it’s possible, though unlikely, that this could happen sooner rather than later, indications are those rogue planets are not rare and in fact it’s entirely possible that the closest world not native to our solar system could be a rogue planet and be sitting within a few light years waiting to be discovered.
The chances are beyond low that such a planet might have hosted a civilization or life at some point, mainly due to ejections being more a phenomenon of very young solar systems instead of old ones, but it’s fun to ponder the possibilities nonetheless.
Not suspiciously, it’s nighttime and clear, so time to head out with the telescope and be sure to check out the star maps at your favorite online book retailer for in-depth explorations into the interesting, weird and unknown aspects of this amazing universe in which we live.