If Neptune’s orbit moves 0.1%, it could destabilize the solar system

A passing star, or stellar flyby, with the potential to knock Neptune out of orbit by just 0.1%, could spell disaster for the entire solar system. But don’t worry, it won’t happen in our lifetime, according to a recent study.

University of Toronto researchers created simulations that observed how far away a passing star would have to be to alter a planet in our solar system’s orbit and cause a chain reaction of changes, as well as the odds of that happening. occur.

“So just like the sun’s gravity can influence very distant objects like comets, okay, comets can be very far from the sun, but they still orbit the sun because of the strong gravity of the sun. A star passing can influence objects in the solar system, so our study had to try to understand how much the stability of the solar system would be influenced by passing stars,” said Garett Brown, a Ph.D. student at the University of Toronto and co-author of the study.

Neptune could ruin everything

In this recent study, the researchers created nearly 3,000 simulations showing what is the smallest amount of influence needed to potentially create huge changes in our own solar system. Turns out it wouldn’t take much.

Brown said that in this particular study, only stars were considered stellar flybys in their simulations — stars 100 times larger than our sun, which are rare. They also simulated flybys with smaller red dwarf stars that are about 5% the size of our sun but 100 times heavier than Jupiter’s.

One of the simulations revealed that if a flyby occurred tomorrow and pulled Neptune out of orbit by just 0.1%, there could be catastrophic consequences for Mercury and Venus.

“We ran the simulations until Mercury crashed into Venus, or something else happened, and then we stopped it. So Mercury might crash into Venus and then that’s it. , nothing else happens,” Brown said.

If Neptune is removed even 0.1% from its orbit, it could have devastating consequences for our solar system.
NASA/JPL-Caltech

“The result is specifically that if you move Neptune by this relatively small amount, then over the lifetime of the solar system you would be 10 times more likely to be unstable. Which still seems like a lot, but if you take the solar system as it is today, completely isolated from the rest of the universe, there is about a 1% chance that Mercury will crash into Venus The solar system is chaotic, it is difficult to predict the future of the solar system beyond a billion years, but in about 5 billion years there is about a 1% chance that Mercury will crash into Venus, so if a star passes by and displaces Neptune from that small amount, so instead of a 1% chance of Mercury crashing into Venus, it’s now a 10% chance,” Brown continued.

Brown postulated that perhaps Mercury and Venus could merge and form an entirely new planet. There was also a case where Earth crashed into Mars. The possibilities were seemingly endless.

“We ran almost 3,000 simulations and in one of those cases we found that Neptune’s change in orbit caused Earth to crash into Mars, so it’s possible something like this “occur where it directly affects Earth. It’s much rarer than Mercury crashing into Venus. If this effect were to happen, it would be very hard to tell at first and very difficult to do anything about it” , Brown added.

But why Neptune? The answer is quite simple: Neptune is farthest away so it’s more likely to be influenced by a stellar flyby, according to Brown.

In this illustration, several rings of dust surround the Sun.  These rings form when the planets' gravity pulls dust grains into orbit around the Sun.  Recently, scientists detected a ring of dust in Mercury's orbit.  Others speculate that the source of Venus' dust ring is a group of previously undetected co-orbital asteroids.
There is currently a 1% chance that Mercury will crash into Venus within the next 5 billion years.
NASA’s Goddard Spaceflight Ce

It will take millions of years, maybe billions

The likelihood of a major celestial event such as this is very slim, – so slim that none of us or your grandchildren or great-grandchildren will be alive to see it – but the odds are not not zero.

“So even if we saw that it was the result of an event, and we could detail what was going to happen, the process itself would still take millions of years before the accident even happened. And then once the crash happened it would just be more difficult so if we were or some future species were advanced space species and had a lot of abilities for interplanetary travel they could attempt to alter Mercury’s orbit to prevent it from happening. Since Mercury is the lightest, it might be the easiest to move, but it also moves very quickly, so it would be quite an undertaking. But if such species was so spacey to attempt something like that, maybe they’d better go somewhere else,” Brown said.

“There’s certainly nothing to be afraid of because the time involved is so, so long. Like, the dinosaurs died 65 million years ago and that’s so, so short compared to how long it would take for an event like this to happen,” Brown added.

Brown said if there was anything to worry about in the nearer future, humans should worry about the sun burning out, but again, that won’t happen for billions of years – five billions of years according to scientists.

“The motivation behind this study itself was just to try to understand how sensitive the solar system is to change. And it’s actually quite robust,” Brown said. “So if you imagine, like in roller coaster, usually a roller coaster can go down a hill, then up and down and up and down But if you imagine the solar system is like a roller coaster car at the bottom of the hill, then you could push the roller coaster back and forth in that little hill and it’s always going to go back down. Because it’s stable and sturdy and the kind of change you’d have to get to push it over the hill, to push it to something catastrophic, that’s the kind of shift where you might have to move Neptune 0.1%.

Arline J. Mercier