Sign in to follow this  
Nicholander

What If Jupiter Or Saturn Suddenly Gained Enough Mass To Become A Star?

Recommended Posts

As the title says above, what would happen if Jupiter or Saturn suddenly gained enough mass to become a star? There's 2 (Or arguably 4) scenarios I can think of:

1. Jupiter or Saturn gains enough mass to become a brown dwarf. (Jupiter's mass would have to be multiplied by 13)

2. Jupiter or Saturn gains enough mass to actually have fusion and become an actual star. (Jupiter's mass would have to be multiplied by 70 - 80)

So, what would happen in these 2 scenarios? And how screwed would we be if this happened?

Share this post


Link to post
Share on other sites

Jupiter is so massive, the barycenter of the Jupiter-Sun system is outside the Sun's surface, making it wobble around as the gas giant orbits it. If, somehow, Jupiter's mass was to be multiplied instantly, it will pull the barycenter even further from the Sun's surface, possibly disrupting the orbits of the other planets, including Earth.

Considering that it may alter the surface temperature of the Earth considerably, I believe anyone living in such an era would be much less fortunate than we are today.

Share this post


Link to post
Share on other sites

Orbits destablize, Earthlings become very sad.

If it was large enough to be a red dwarf, it wouldn't be that bright, and Earth's temperature wouldn't change much.

The major problem is the orbits...

Share this post


Link to post
Share on other sites

Okay, I just tried the first scenario in Universe Sandbox (Not Universe Sandbox 2).

MwxDClR.png

This is the result after a little over 100 years.

Earth's orbit now has a perisol of Venus's orbit and an aposol of Mar's orbit. This doesn't end well for Humans, as on the perisol the average global temperature is 40.1C/104F. Oh, and Mercury ejected itself from the Solar System.

Share this post


Link to post
Share on other sites

Well a brown dwarf does actually have fusion, just not Hydrogen fusion. It's not even break-even fusion, IIRC. It doesn't need fusion to counteract gravity, so it can away with deuterium fusion.

Share this post


Link to post
Share on other sites

Beside the gravitational perturbations that would come with having an object 80 times heavier than Jupiter in its orbit, it wouldn't really affect another planet significantly.

From the point of view of Neptune, Jupiter and the Sun are approximately in the same place. But Jupiter as a star would be 5000 times dimmer, so Neptune would receive about 0.02% extra solar energy, enough to change the average temperature by less than 1/20th of a degree.

In the case of Mars, the Sun would be about 3 times closer than Jupiter, so Jupiter would contribute less than 0.003% extra energy (light and heat). It wouldn't really make a difference in its habitability.

The only bodies significantly affected would be the satellites (planets?) of Jupiter. If Jupiter was 80 times its current mass, it would be a red dwarf star with 0.02% of the Sun's luminosity. Assuming its satellites orbit at the same distance, Callisto would receive about the same amount of energy as the Sun gives to Earth. So what would probably happen is a lot of its surface ice would sublimate to form a water vapor atmosphere, with liquid water running underneath, possibly a global ocean. Its surface temperature would be about the same as on Earth.

Ganymede would receive a little more energy than Venus does from the Sun. So it would also have a water vapor atmosphere, but its surface temperature would be significantly hotter. It would possibly have a boiling water ocean surface.

Europa would receive a little more energy than Mercury does from the Sun. Coupled with its smaller size, its water vapor would probably be lost to space relatively quickly, and it would become a comet with a thick water vapor ring in its orbit. After a few years there would probably only remain the rocky core at about 90% of Europa's radius.

Io would receive about 4 times as much energy as Mercury does from the Sun. It already doesn't have much water, but the high temperature would be enough to vaporize some of the rock. It would probably end up with a thick sulfur atmosphere and oceans of liquid rock (lava) at the surface.

Share this post


Link to post
Share on other sites

So, according to you, metaphor, pretty much nothing would happen to us? But in Universe Sandbox, screwed up Earth's orbit pretty badly and made Mercury eject itself from the solar system! And that was only with 13 times mass, not 80! So you may have screwed up on your maths somewhere, just saying. Also, you say you couldn't see the Jupiter-Star in the sky or night sky any more you could see it now? I really doubt that.

Share this post


Link to post
Share on other sites

No, he said that aside from the gravitational perturbations, we wouldn't notice much difference. Jupiter would be several thousand times less bright to an observer on earth than the sun, and most of the light emitted would be in the infra red range anyway.

Share this post


Link to post
Share on other sites
No, he said that aside from the gravitational perturbations, we wouldn't notice much difference. Jupiter would be several thousand times less bright to an observer on earth than the sun, and most of the light emitted would be in the infra red range anyway.

That's like saying that aside from the effects of surface impact, jumping out of an airplane without parachute isn't really that lethal. Completely correct while ignoring the big white elephant in the room.

Share this post


Link to post
Share on other sites
That's like saying that aside from the effects of surface impact, jumping out of an airplane without parachute isn't really that lethal. Completely correct while ignoring the big white elephant in the room.

I think it's a fair enough point. People intuitively know that you're going to go splat if you fall from three miles in the air.

On the other hand, when people think of a second star in the solar system, they imagine it rivalling the sun, being dazzlingly bright, pumping out huge amounts of heat to us here on earth. That's not the case, and I for one think that's an interesting fact.

Share this post


Link to post
Share on other sites
Okay, I just tried the first scenario in Universe Sandbox (Not Universe Sandbox 2).

http://i.imgur.com/MwxDClR.png

This is the result after a little over 100 years.

Earth's orbit now has a perisol of Venus's orbit and an aposol of Mar's orbit. This doesn't end well for Humans, as on the perisol the average global temperature is 40.1C/104F. Oh, and Mercury ejected itself from the Solar System.

Aphelion and perihelion, please, don't mix Latin and Greek.

And judging by the polygon-like shape of Venus's orbit, it seems that's a VERY rough simulation. I don't think it would be reliable for 100 years at all.

Share this post


Link to post
Share on other sites

Even if accurate, the main problem would be that somehow suddenly one gas giant gets many times larger in mass. In reality, such a discontinuous effect makes almost no sense. The mass might e.g. be streaming in from outside the solar system over the course of many many years. Many such scenarios are less brutal to the existing orbits than just "make it bigger".

Share this post


Link to post
Share on other sites

I honestly don't think the mass increase of Jupiter would have the affects that some people would think. Yes it would change a bit in our solar system but it would not be a sudden change. The biggest thing would be that most of the planets closest to Jupiter would have their orbits affected first. The asteroid belt, often forgotten here in KSP, would actually be the biggest threat to Earth, as most of the rocks in that field would have their orbits disrupted by the new gravity field, sending them in an erratic orbital pattern if not throwing them completely out of orbit like a giant shotgun blast.

Share this post


Link to post
Share on other sites

The instability of the orbits would depend a lot on how Jupiter got that massive in the first place. If 79 Jupiters' worth of mass instantly appeared at the same point in space as Jupiter, the orbits of the planets would experience the equivalent of a sudden jerk, which would result in a lot more instability than if the 79 Jupiters' worth of mass appeared there gradually over many years.

I don't know how well Universe Sandbox models gravitational effects. In principle, a 1 AU orbit around a star with another star 1/12th as massive orbiting at 5 AU would not be that unstable. (Just for fun I tried it here and Earth's orbit didn't move a bit in 100 years.)

Share this post


Link to post
Share on other sites

Earth's orbit now has a perisol of Venus's orbit and an aposol of Mar's orbit. This doesn't end well for Humans, as on the perisol the average global temperature is 40.1C/104F. Oh, and Mercury ejected itself from the Solar System.

While unpleasant, and screwing up all kinds of ecosystems due to the seasons being off schedule and all sorts of adaptations to the seasonal cycle suddenly being inappropriate... that's probably actually survivable.

The global temperature won't be that high since the perihelion is brief and the oceans have lots of thermal inertia - they won't have time to heat up fully (this is why the hottest/coldest time of year is well after the summer/winter solstice).

I'd avoid continental interiors though - they will probably be crazy climatically extreme.

Agriculture will have to adapt A LOT to the weird seasons and ecological chaos, but humanity should survive, I think.

Share this post


Link to post
Share on other sites

You'd need to run some models that puts at least all the major bodies in the solar system complete with it's latest accurate measurements of six orbital parameters - and don't forget to modify the mass of Jupiter to the lightest red dwarf. >2 - body problems is hard to solve : no real analytic derrivation unless for lagrangian points.

But most likely that Earth's orbit will increasingly being more eccentric. Mercury might be out due to it's currently high orbital eccentricity even today. Outer planets might migrate in - someday, Jupiter will be out, after making chaos in the whole system.

The radiation won't be a problem, at all..

Edited by YNM

Share this post


Link to post
Share on other sites

Earth's orbit now has a perisol of Venus's orbit and an aposol of Mar's orbit.

a perisol is an umbrella. i think you mean perihelion.

Share this post


Link to post
Share on other sites
Is anyone going to mention 2010: Odyssey Two​?

I was actually thinking about that just now, kinda.

Share this post


Link to post
Share on other sites
and most of the light emitted would be in the infra red range anyway.
So Jupiter would turn on my tv, and all tvs?

Share this post


Link to post
Share on other sites
So Jupiter would turn on my tv, and all tvs?

If for some reason it would blink at the right frequency...

Share this post


Link to post
Share on other sites

On the other hand, when people think of a second star in the solar system, they imagine it rivalling the sun, being dazzlingly bright, pumping out huge amounts of heat to us here on earth. That's not the case, and I for one think that's an interesting fact.

Hardly matters to planets that no longer belong to the solar system thanks to perturbations of their orbits.

Though it's true that other than that significant effect, there won't be much significant effect.

Share this post


Link to post
Share on other sites
This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this