How passing stars could shake our solar system's future stability
Researchers Nathan A. Kaib and Sean N. Raymond have evaluated how passing stars can affect 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, emphasize that previous research often assumed the Solar System was isolated. In their simulations, they included external influences and concluded that close flybys of stars significantly increase the likelihood of orbital instability.
Possible scenarios
The scientists simulated thousands of possible scenarios spanning 5 billion years, taking into account the current orbits of the eight planets in the Solar System and Pluto. Unlike isolated models that might underestimate future orbital changes of giant planets by more than an order of magnitude, the new simulations show that our planets and Pluto may be much less stable than previously thought.
The study revealed that over the span of 5 billion years:
- Pluto, which in isolated models was completely stable, has a 5% chance of destabilization due to passing stars;
- The chance of destabilization of Mercury increases by 50–80% compared to isolated simulations, which estimated the risk at about 0.8–1%;
- There's a 0.3% chance that Mars will be lost due to a 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 indicates that while the stability of the Solar System during its main life stage (it's estimated that, in about 5 billion years, the Sun will become a red giant, potentially destroying Earth) is very probable, it's not guaranteed. Passing stars pose a significant risk factor for our cosmic "backyard."
