A Canadian research team has run almost 3,000 simulations of our solar system. In it they wanted to test the effects of passing stars on us and our solar system. If the gravitational pull of an alien star shifted Neptune’s orbit by just 0.1 percent, it would shake up our solar system completely.
Toronto (Canada) – In the universe, gravitational forces determine the interaction of planets and other celestial bodies. When a massive star flies past our solar system, its gravitational pull could knock the outermost planet Neptune out of orbit. Even an orbit shift of 0.1 percent could lead to the collapse of order in our solar system. How likely is the scenario? And when will the solar system descend into chaos?
Small disturbances in the orbit would cause our solar system to wobble
A Canadian research team consisting of Garett Brown and Hanno Rein from the Department of Physical and Environmental Sciences at the University of Toronto at Scarborough and the Department of Physics at the University of Toronto performed 2,880 simulations . They should all study the effects of a flyby from an alien celestial body on our solar system. Rein also works for the University of Toronto’s Department of Astronomy and Astrophysics.
The study focused on objects that were too weak to directly destabilize a planetary system. Nevertheless, these objects should be strong enough to measurably disturb the dynamic state of our solar system. The two researchers were able to show that even small disturbances caused by stellar flybys can affect the stability of planetary systems during their lifetime – even if this does not happen immediately.
When will a foreign celestial body cause our solar system to shake? How long will we be safe on Earth from space hazards?
The destabilization of Neptune’s orbit would be gradually transmitted to the other planets. On Earth, however, you would only notice something of this after 20 million years – the reason is the great distance between the planets. Earth and Neptune are, on average, about 4,540 million kilometers (4.5 billion kilometers) apart. The average distance between Jupiter and Earth is almost 780 million kilometers and the distance between Earth and Mars is around 230 million kilometers.
The likelihood of such a scenario actually occurring is very low. According to the scientists, it would probably happen once in 100 billion years that an alien massive object could disturb Neptune’s orbit. The disruption will not have a serious impact on our solar system as long as it is less than 0.1 percent.
Star flying by: Criticism of the study about the possible wobbling of our solar system
The researchers have also shown that successive smaller perturbations do not have a major impact on changing planetary orbits. Such small perturbations are insignificant and focus has been on the larger interstellar encounters. However, they did not consider stellar binaries, even though half of all known stars are part of binaries. However, the two researchers assume that the strength of the disturbance would be two to 3.6 times stronger in a binary star system flying past.
Also, Brown and Rein have neglected the impact on Planet 9. A large part of the international research community is convinced that there is another planet outside of the orbits of Neptune and Pluto that has not yet been found. According to the researchers, a stellar flyby would cause the largest relative change in Planet 9. However, they suspect that Planet 9 will only have a weak impact on the rest of the solar system.
To study the effect of stellar flybys on our solar system
The study, titled “On the long-term stability of the Solar System in the presence of weak perturbations from stellar flybys,” was published June 30, 2022 in the published in the journal Monthly Notices of the Royal Astronomical Society. The simulations have been limited to our solar system, although the analytical estimates are general and intended to apply to any planetary system. Future work should examine the effects of weak stellar flybys on exoplanet systems, according to Brown and Rein.