Scientists predict how our solar system is going to disintegrate in the end

There can be no end to our informed imagination. When we think about our solar system, this imagination becomes very complicated. But still can scientists stop doing that and publish what their computer simulations reveal? This is what one such recently published paper predicts.... 

One day, our Sun will die, ejecting a large proportion of its mass before its core shrinks down into a white dwarf, gradually leaking heat until it's nothing more than a cold, dark, dead lump of rock

But the rest of the Solar System will be long gone by then. According to new simulations, it will take just 100 billion years for any remaining planets to skedaddle off across the galaxy, leaving the dying Sun far behind.

To predict exactly how this happens is difficult. The greater the number of bodies that are involved in a dynamical system, interacting with each other (like our solar system), the more complicated that system grows and the harder it is to predict (the outcome). This is called the N-body problem. Because of this complexity, it's impossible to make deterministic predictions of the orbits of Solar System objects past certain timescales. Beyond about five to 10 million years, certainty flies right out the window.

But still this is how it might happen ....

In about 5 billion years as it dies, the Sun will swell up into a red giant, engulfing Mercury, Venus and Earth. Then it will eject nearly half its mass, blown away into space on stellar winds; the remaining white dwarf will be around just 54 percent of the current solar mass.

This mass loss will loosen the Sun's gravitational grip on the remaining planets, Mars and the outer gas and ice giants, Jupiter, Saturn, Uranus, and Neptune.

Secondly, as the Solar System orbits the galactic centre, other stars ought to come close enough to perturb the planets' orbits, around once every 23 million years.

"By accounting for stellar mass loss and the inflation of the outer planet orbits, these encounters will become more influential," the researchers wrote.

"Given enough time, some of these flybys will come close enough to disassociate - or destabilise - the remaining planets."

With these additional influences accounted for in their calculations, the team ran 10 N-body simulations for the outer planets (leaving out Mars to save on computation costs, since its influence should be negligible), using the powerful Shared Hoffman2 Cluster. These simulations were split into two phases: up to the end of the Sun's mass loss, and the phase that comes after.

Although 10 simulations isn't a strong statistical sample, the team found that a similar scenario played out each time.

After the Sun completes its evolution into a white dwarf, the outer planets have a larger orbit, but still remain relatively stable. Jupiter and Saturn, however, become captured in a stable 5:2 resonance - for every five times Jupiter orbits the Sun, Saturn orbits twice (that eventual resonance has been proposed many times, not least by Isaac Newton himself).

These expanded orbits, as well as characteristics of the planetary resonance, makes the system more susceptible to perturbations by passing stars.

After 30 billion years, such stellar perturbations jangle those stable orbits into chaotic ones, resulting in rapid planet loss. All but one planet escape their orbits, fleeing off into the galaxy as rogue planets.

That last, lonely planet sticks around for another 50 billion years, but its fate is sealed. Eventually, it, too, is knocked loose by the gravitational influence of passing stars. Ultimately, by 100 billion years after the Sun turns into a white dwarf, the Solar System is no more.

That's a significantly shorter timeframe than that proposed in 1999. And, the researchers carefully note, it's contingent on current observations of the local galactic environment, and stellar flyby estimates, both of which may change. So it's by no means engraved in stone.

Source: https://iopscience.iop.org/article/10.3847/1538-3881/abb8de