Passing stars could destabilise solar system's future stability
Researchers Nathan A. Kaib and Sean N. Raymond assessed the impact of passing stars on the long-term stability of the solar system. What does the future hold for Earth?
The authors of the article "The influence of passing field stars on the solar system’s dynamical future", published in ScienceDirect, emphasise that previous studies often assumed the solar system to be an isolated system. In their simulations, they considered external influences and concluded that close flybys of stars significantly increase the probability of orbital instability.
Possible scenarios
The scientists simulated thousands of possible scenarios over the span of 5 billion years, taking into account the current orbits of the solar system's eight planets and Pluto. Unlike isolated models, which may underestimate future orbital changes of the giant planets by more than an order of magnitude, the new simulations indicate that our planets and Pluto may be much less stable than previously thought.
The mentioned study showed that over a 5 billion-year perspective:
Pluto, which was completely stable in isolated models, has a 5% chance of destabilisation due to passing stars;
the chance of Mercury's destabilisation increases by 50-80% compared to isolated simulations, which estimated the risk at about 0.8-1%;
there is a 0.3% chance that Mars could be lost due to collision or ejection from the solar system;
Stability of our system
Earth has a 0.2% probability of being involved in a planetary collision or being ejected from its orbit.
The study shows that, although the stability of the solar system during its main life phase (it is estimated that in about 5 billion years, the Sun will transform into a red giant, which will destroy Earth anyway) is very likely, it is not guaranteed. Passing stars become a key risk factor for our cosmic "backyard."
