Passing stars could shake solar system's cosmic stability
Researchers Nathan A. Kaib and Sean N. Raymond have evaluated the impact of passing stars on the long-term stability of the Solar System. What future awaits Earth?
The authors of the article published in ScienceDirect, "The influence of passing field stars on the solar system’s dynamical future," point out that earlier studies often assumed the Solar System was isolated. In their simulations, they considered external influences and found that close flybys of stars significantly increase the probability of orbital instability.
The scientists simulated thousands of possible scenarios over 5 billion years, taking into account the current orbits of the eight planets of the Solar System and Pluto. Unlike isolated models, which may underestimate future orbital changes of giant planets by more than an order of magnitude, the new simulations suggest that our planets, including Pluto, may be significantly less stable than previously thought.
The study found that over the span of 5 billion years:
- Pluto, which appeared completely stable in isolated models, has a 5% chance of destabilization due to passing stars;
- The chance of destabilizing Mercury 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 may be lost due to a collision or ejection from the Solar System.
Earth has a 0.2% probability of being involved in a planetary collision or being ejected from its orbit.
The study suggests that although the stability of the Solar System throughout its main lifespan is very likely, it is not guaranteed. It is estimated that in approximately 5 billion years, the Sun will expand into a red giant, potentially destroying Earth. Meanwhile, passing stars pose a significant risk factor for our cosmic "neighborhood."
