How our galaxy will kill our solar system in a trillion years, planet by planet - SYFY WIRE

Mind you, this is all true, but that's not really what happens to the solar system, just the Sun and first three planets (one of which we have a vested interest in).

Any random error, no matter how small, propagates through the equations, growing larger over time, and eventually changes the solar system configuration in unpredictable ways.

Artwork depicting a rogue planet, ejected from its solar system, wandering the galaxy.

That's important, because as it does so its gravity gets weaker, and the orbits of the planets expand — they found that the planets Mars through Neptune have their orbits get bigger by a factor of about 1.85 as the Sun loses about half its mass in the next 7 billion years.

More than that, they also included the chances of stars in the galaxy getting close enough to the Sun to have an affect.

The Sun's gravity is weaker, planets are more distant, and a chance stellar encounter has an easier time of stripping planets away, flinging them out into interstellar space.

A plot showing the times planets are ejected in ten (color-coded) simulations of the solar system.

For example, the times the last planet in each sim was ejected is in the top row, where the earliest (olive) is 45 billion years, and the latest (purple) is over 300 billion.

In some sims, the outer planets were destabilized after roughly 45 billion years.

Also, once the first planet is ejected, the system is destabilized enough that the next two follow within 5 billion years.

They note that it may be the actual last planet to survive, since it's closest to the Sun and needs a really close stellar encounter to fling it away.

In the paper, they note that they don't include stellar encounters with binary stars, which are more efficient at poking at the solar system, so the results they find are likely upper limits to how long the system will last.

Illustration of a cosmic train wreck: The Milky Way/Andromeda galaxy collision, four billion years from now.

Also, the Milky Way will collide with the Andromeda Galaxy in 4.6 billion years, while the Sun is still a relatively normal star, and they didn't account for that either.

But more than that, there's a strange attraction to the idea of deep time, not just millions or even billions but trillions of years, or even epochs that make those numbers seem like a single tick of the clock.

What if we let time run on really long.

The Universe is almost 14 billion years old, and we think that's a long time.

But really, it's just getting started