With the help of various simulations, scientists decided to find out how most planets of our solar system will die.
Many articles on this topic write that the Sun will use up its nuclear fuel, turn into a red giant, then absorb Mercury, Venus and Earth, release its outer layers. Then the Sun will turn into a white dwarf, will cool for eternity until it turns black and freezes to almost absolute zero. This is what Syfy Wire writes about.
However, this may not happen with the solar system, but with the Sun, Mercury, Venus, Earth, as well as Mars and four giant planets.
A recently published article says that in general, the movement of the planets around the Sun is predictable. They follow the equations first outlined by Isaac Newton in the 17th century, which are still in use today. But in the long run, they will not work. In particular, if there are more than two bodies that rotate around each other, after a long period of time the system will become chaotic.
They will not fly everywhere, it is only in the mathematical sense of the theory of chaos. That is, it is impossible to predict exactly where the planets will be in the distant future, as you can not measure their position and movement at the moment.
Any random error spreads through the equations, increases over time and eventually unpredictably changes the configuration of the solar system.
To avoid this situation, it is possible to compensate somewhat by including some uncertainties in the mathematical calculations, and then, by performing the equations many times, each time changing these values. As a result, after a while, a pile of different configurations will appear, which can be statistically looked at.
In this new article, the scientists decided to go even further. They turned on the Sun, which loses its mass when it becomes a red giant. This is an important point because its gravity weakens and the orbits of the planets expand.
The scientists have found that the orbits of the planets of Mars through Neptune increase by about 1.85 times, because the Sun loses about half its mass within the next 7 billion years. They also included the probability that stars in the galaxy would be close enough to the Sun to have an effect.
The stars themselves are small and very distant from each other, so such collisions are quite rare, but possible. If you run the simulation far enough into the future, a star escaping from the solar system will be inevitable.
The scientists have divided the simulation into two parts. The first was before the Sun lost its mass, and the second was after. For this simulation, they included semi-random star collisions using a true galactic environment (the number of stars per cubic light year and their movement).
They found that in phase 1, the planets are too close to the Sun for this effect to have much effect. The stars would have to pass much closer, if only to distance Neptune, so in trillions of years, such a collision is very rare.
However, as soon as the Sun becomes a white dwarf, and the planets move further, the chances will increase. It is also worth considering that the gravity of the Sun is weaker, and the planets are more distant, so in an accidental collision with a star, the planets are easier to eliminate and throw away in interstellar space.
The researchers conducted 10 complete simulations in this configuration, but they received similar results every time they were sure of their conclusions.
It turned out that a star can travel about 75 billion km every 10 billion years. This is close enough to lead to large collisions, and in some simulations, the outer planets were destabilized after about 45 billion years.
In all simulations, Jupiter, Saturn, Uranus and Neptune are displaced after a maximum of 1 trillion years. Jupiter usually remains the last surviving planet, because it is the most massive and most difficult to get rid of it.
On average, the first planet is lost in 30 billion years, and the last planet is lost in about 100 billion years. Once the first planet is displaced, the system is so destabilized that the next two will follow within 5 billion years. The last planets are usually delayed for another 50 billion years, because there are no other planets left in the system with which to interact.
However, the scientists did not take into account one important thing in their research – Mars. They believe that it may be the last planet that will survive, because it is closest to the Sun and needs a very close collision with a star to throw it away.
The scientists noted that they do not include star collisions with double stars, which are more effective to penetrate the solar system, so the results are the upper limit of how long the system can last.
Also in 4.6 billion years, the Milky Way will collide with the Andromeda Galaxy, while the Sun will still be a relatively normal star.