Good news! The solar system will hold together for now

If you’re lying in bed at night fearing that planets in the solar system will ricochet around the galaxy, you can take comfort.

We have at least 100,000 years before that happens, according to new calculations.

In a new study, mathematicians Angel Zhivkov and Ivaylo Tunchev from Sofia University in Bulgaria present analytical evidence for the stability of the solar system over the next 100 millennia, including the eight planets and Pluto.

Their calculations, which have not yet been peer-reviewed, show that the orbits of these bodies will not vary significantly over this period.

This may sound strange; after all, the solar system has been doing its job here for about 4.5 billion years already. But it’s not, in fact, easy to model and predict what it will continue to do in the future.

Studies, of course, have been carried out to try to calculate the future of the solar system, using advanced computing to model the movements of the planets over millions or billions of years.

However, in order to cover such long timescales, they omit some of the finer details.

Although Zhivkov and Tunchev’s work covers a much shorter period of time than other efforts, it increases the reliability of the results, they say.

Indeed, it takes into account the deviations in the initial conditions, such as the orbital eccentricities and the inclinations of the planets, as well as the masses of all the bodies of the system.

The ultimate fate of the solar system is one that has puzzled scientists for a very long time. It was Isaac Newton who proposed that the mutual interactions between the planets would eventually drive the solar system into chaos. The long-term dynamic stability of our home planetary system has been brain water ever since.

Indeed, the more bodies there are in a dynamical system, the more difficult it becomes to predict how they will behave. Two bodies, locked in mutual orbit, are relatively simple to describe and predict mathematically.

However, the more bodies you add, the more complicated the math becomes. This is because the bodies begin to disrupt each other’s orbits, adding an element of chaos to the system. This is called the many-body problem.

Solutions can be derived for specific individual cases, but there is no single formula describing all many-body interactions. And the solar system is indeed very complex, with not only eight planets and the Sun, but also asteroids, dwarf planets and other drifting elements.

We can probably ignore very small things, like asteroids, but even so, there are still plenty of bodies in the system.

Zhivkov and Tunchev developed a numerical method that translates the orbital elements of the planets (and Pluto) into 54 first-order ordinary differential equations. The computer code, run on a desktop computer, then performed the calculations over 6,290,000 steps, with each step representing about six days.

Calculations suggest that “[t]The configuration of the osculating ellipses on which the planets move around the Sun will remain stable for at least 100,000 years in the sense that the semi-major axis of each planet varies by less than one percent.

In other words, the solar system is not yet going to mimic the galactic billiards.

Even when the initial conditions and masses were changed, the solar system remained stable according to the team’s calculations, and the researchers suggest that the stability could ultimately be maintained for a million or even a billion years, although a more powerful computer is needed to perform the calculations. .

Previous simulations have revealed that it would take around 100 billion years for the solar system to break up and disperse through the Milky Way.

By then the Sun will be well and truly dead, living its afterlife as a white dwarf, so it’s unlikely humanity will be around to see it, unless we’ve managed to find a safe haven elsewhere, far away. The likelihood of this, however, is questionable.

In any event. Existential scare aside, you can read the team’s article on the arXiv preprint server.

Arline J. Mercier