The original question was: I have heard Jupiter referred to as a failed star. That if the cosmic chaos of the early solar system had worked out a little different, and Jupiter had gotten a bit more mass, it might have been able to light the fusion engine and become a star.
Two questions.
How close was Jupiter to becoming a star?
If something really big slammed into Jupiter today, could it trigger nuclear fusion?
Ok and a third question. If Jupiter did in fact get slammed with something big enough to trigger nuclear fusion, and it became a star, how long would it take to substantially alter the ability for earth to sustain life as we know it?
Physicist: That is a really cool question!
I heard the same thing a while ago, but Jupiter is a long way from being a star. That estimate was based on some old nuclear physics (like 1980’s old). By being awesome, and building neutrino detectors and big computers, we’ve managed to refine our understanding of stellar fusion a lot in the last few decades.
Although the material involved (how much hydrogen, how much helium, etc.) can change the details, most physicists (who work on this stuff) estimate that you’d need at least 75-85 Jupiter masses to get fusion started. By the time a planet is that large the lines between planet, brown dwarf (failed star), and star get a little fuzzy.
So, for Jupiter to become a star you’d need to slam so much additional mass into it, that it would be more like Jupiter slamming into the additional mass.
If you were to replace Jupiter with the smallest possible star it would have very little impact here on Earth.
There’s some debate over which star is the smallest star (seen so far). OGLE-TR-122b, Gliese 623b, and AB Doradus C are among the top contenders (why is every other culture better at naming stars?), and all weigh in around 100 Jupiters. They are estimated to be no more than 1/300th, 1/60,000th, and 1/1,000th as bright as the Sun respectively. So, lets say that Jupiter suddenly became “OGLupiter” (replaced by OGLE-TR-122b, the brightest of the bunch, and then given the worst possible name). It would be a hundred times more massive, 20% bigger, a hell of a lot denser, and about 0.3% as bright as the Sun.
At it’s closest Jupiter is still about 4 times farther away from us than the Sun, so OGLupiter would increase the total energy we receive by no more than about 1 part in 5 thousand (about 0.02%). This, by the way, is much smaller than the 6.5% yearly variation we get because of the eccentricity of Earth’s orbit (moving closer and farther away from the Sun over the course of a year). There would be effectively zero impact on Earth’s life.
There are examples of creatures on Earth that use the moon for navigation, so maybe things would eventually evolve to use OGLupiter for navigation or timing or something. But it’s very unlikely that anything would die.
OGLupiter would be around 80 times brighter than a full moon at its brightest, so for a good chunk of every year, you’d be able to read clearly at night. It would be very distinctively red (being substantially colder than the Sun), and it would be clearly visible even during the day.
Where’s that “Thumbs Up” button…
Great question & great read.
Chin has been thoroughly scratched. Great read!
Thanks, y’all!
How would OGLuptier affect our orbit around the sun?
I was just now hoping that no one would ask that.
It wouldn’t tear the Earth out of orbit directly, but increasing Jupiter’s mass from 0.1% of the Sun’s mass to 10% of the Sun’s mass would probably throw a wrench in the solar system’s clockwork.
Specifically (guess) it would cause the other planets to fall into phase lock with OGLupiter. That is, the other planets would have years that are simple fractions of OGLupiter’s year (“2/3”, “2”, “1/2”, etc.).
But, that’s a complete shot in the dark. I wouldn’t be surprised at all if the correct answer were: “it wouldn’t affect our orbit”.
If there are any planetary scientists reading this with access to some decent solar system simulation software, let us know what would happen?
Wow. When I first read the question, I though “Duh. Earth would immediately be completely destroyed.” But apparently I was very wrong.
“OGLupiter would be around 80 times brighter than a full moon”
What would its apparent size be to us, compared to the full moon?
It wouldn’t be much bigger than Jupiter, which looks like a point to the naked eye (although you can see Jupiter as a disc with good binoculars).
So, OGLupiter would be a piercingly bright, red point at night, and a sky pimple during the day.
I recently wrote an article that described Jupiter as a failed star. I was actually wondering about what it’s effect would be on the solar system if it gained that much mass.
Great post!
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If Jupiter were 0.1 solar masses, since it orbits 5AU from the Sun, the center of mass of the solar system would be 0.5AU out from the Sun on the Sun-Jupiter line. This is well out from the Sun, which has a radius of about 0.005AU. So the Sun and Jupiter (and all the other planets) would orbit a point nearly out to Venus, instead of the other way around.
Are there any stable orbits in a binary system like that, interior to the two stars’ orbits?
Damn!
I’m so used to thinking about the planets’ effects on the Sun in terms of tiny pertubations, but yeah, 10% is not a tiny fraction.
So, inner solar system: gone.
Outer solar system: rearranged.
The problem with systems containing two primary objects (binary systems) is that they bring the “three-body problem” into play, and stable orbits become more and more rare. The Sun is so heavy that every planet interacts with it directly, and barely notices the effects of the other planets at all (because none of them has the mass to change the Sun’s position noticably). For example; if you wanted to model Earth’s orbit, the first step is to ignore all the other planets.
The best way to solve this (as that third body) is to orbit so far away that the two primary bodies “look” like one body, or at the very least the heavier body barely seems to be moving. You can see this in the Pluto/Charon system (they’re the primaries with to tiny additional bodies: Hydra and Nix) and also in the our closest neighboring star system, Alpha Centauri (Alpha Centauri A and Alpha Centauri B are the primaries, with Proxima Centauri the third, and very distant, body).
There are also some computer simulations that indicate that it may be possible to have a stable orbit very close to either of the primary bodies, but I haven’t heard of that actually being seen (there’s every likelihood that, although stable, no planets would naturally form in that orbit).
Finally, although not technically an orbit, it is possible to cool your heels indefinitely in the Lagrange points of a binary system. It’s worked for the Trojan asteroids for a couple billion years, with a bigger Jupiter it might just work for entire planets.
(1) Lagrangian points are sexy.
(2) (a) The ratio of Jupiter’s gravitational tug on Earth to the Sun’s is at most
. Take this as a reasonable estimate of when one body’s gravitational effect dominates another’s.
(b) In our OGlupiter system, we might suppose an object so close to the Sun that the Sun dominates OGlupiter’s pull would have a similar ratio. Setting up the equation,
.
This is quadratic with positive root r = 0.1 AU.
So this seems a reasonable regime for stable orbits. That’s pretty close, though; by contrast, Mercury’s orbit varies between 0.3AU and 0.5AU. It’s outside the Sun’s surface (since the radius of the Sun is 0.005AU). However, it looks like the Roche limit for an object of the Earth’s density (5000 kg/m^3) is actually within the Sun’s radius, so it’s not like the Earth would be torn up.
(c) On the other side, the regime where Oglupiter’s gravity dominates is given by switching M_sun and M_OG in the prior equation: r = 0.01 AU.
Double check me, I don’t know if I believe my conclusion. The furthest of (real) Jupiter’s moons orbits at 0.1AU.
I hope the tex tags worked.
wicked but what i want to know is if jupiter did become a star how long would it burn for? I mean do smaller stars last longer than bigger ones?
In general smaller stars burn longer than big ones.
Bigger stars exert more pressure on their cores, which drives fusion faster and causes them to run out of fuel faster. A Jupiter sized star (absolutely tiny) would last a very, very long time.
How long is very, very long?
Much longer than the lifetime of the Sun. I can’t give you a better number that that.
I find this very intriguing. Could two stars exist so close together? What kind of gravitational forces could they exert against one another? I know 5 AU is over 450 million miles, but that’s not really much in comparison with the vast expanse of known space. Would this new star still orbit the sun, or would its new mass and density allow it to break free and travel away from the solar system?
Absolutely!
A two-star solar system is called a “binary system”, and about a third of the stars in the sky are binary, including the brightest, Sirius. HM Cancri is one of the closest orbiting pair of stars ever seen. Their separation is approximately 0.0005 AU, which is about one fifth the distance to the Moon. However, HM Cancri is pretty unusual.
Ok so what effect would a “jupiter” star have on the orbit of the asteroid belt?
With Jupiter’s mass: no effect.
With OGLupiter’s mass: no asteroid belt.
Wow. I hadn’t even considered the asteroid belt.. Quite the interesting thread.
Im guessing this idea sprung up from an interest in heating and lighting up the outer reaches of our system, to make the idea of an outpost somewhat more reasonable (which is where my interest came in for doing this). I’m also guessing that with an increase of such mass the moons and planets nearest would form around OGLupiter’s orbit (best case scenario), My question’s are since Titan is the most earth like in our solar system but with a much lower gravity, would Titans atmosphere be stripped away?, also since Europa and Enceladus have ice and salt water on them, would enough heat be given off to make a human colony or even start a terraform project worthwhile in the not so distant future.
Maybe!
Io and possibly Callisto are just about in the goldilocks zone for an OGLupiter.
Europa would be too hot, and Ganymede would be too cold.
Let’s say, for the sake of argument, that something amazing happens and Jupiter does indeed ignite to become a star, a very little star. So, it would probably ruin our view of the night sky whenever it was in position and it’s probably too small and too far away to really effect the Earth. Here’s a goofy question, if OGLupiter did pull on the Earth could it slow our orbit and if so, if our orbit slowed, would time or our perception of time also slow?
How would an OGLupiter effect the orbits of Comets? Do you think it would be strong enough to suck them in?
How would we be effected if Jupiter became a teeny, unstable star only to explode soon after it came alive?
Would we get hit with all kinds of radiation? Gamma rays and the like? And would that destroy the Earth or just make things very difficult, or just make pretty lights in the sky?
Forgive my questions if they are uneducated. I am just a regular “Joe” err rather “Jane” who is NOT a mathematician nor an astronomy student I just have a real fascination and curiosity.
The Earth’s orbit determines how we define one of our time units (years), but it doesn’t actually have any affect on time itself. Similarly, whether you measure your height in feet or meters, you’ll still be the same actual height.
Jupiter already cleared the inner solar system of almost every comet billions of years ago. What planets do is scatter comets into new, random orbits over and over until the comet’s new orbit intersects something. Usually the Sun, and sometimes Jupiter itself.
If Jupiter’s mass increased, it might scatter more distant comets, but the effects wouldn’t be noticeable for a very long time, and just being a tiny star would have no impact at all.
If, somehow, the stars aligned (so to speak) and a star as small as an OGLupiter went super nova (stars that nova need to be much bigger), then nothing on Earth would come close to surviving. Maybe, maybe, if the Earth were on the exact oppose side of the Sun. But probably not. We’ll have to try it to know for sure.
Also, ask anything you like! A scholar is a person who asks, not a person who knows.
Hey what would happen if Jupiter want here? I have to do this researcher paper about jupiter.
Oh and nice question and read!!!!!
If you’re asking about Jupiter not being present at all, then the biggest effect on the Earth would probably be that we’d be hit by comets and meteors more often. Jupiter is remarkably good at eating up comets that have orbits that take them close to the inner solar system, so without it we’d have to contend with all of the objects that Jupiter would have gotten rid of.
And now it seems that we have the observation:
http://www.bbc.co.uk/news/science-environment-19401891
As an amature in astrophysics I found this extremely interesting, I ran this as a simulation on a universe simulator and the results were surprising, I can make a video of it and put it on youtube and comment again with the link, the sad thing it seems is that this is a very old post, I hope you will respond and let me know if you would like me to make that video or not, I’ll be checking back to see if you’ve responded or emailed me
@Joshua
That would be great!
Me again, I just had a quick question about the temperature. what would the approximate temperature of OGLupiter be? and I am trying to make that video but I have work everyday, Promise I’ll make it though
The wikipedia article for the actual star puts the temperature at 5,700 K.
Would an OGLupiter light up the other celestial bodies in our solar system causing them to be more visible in the night sky? Or would the light from OGLupiter be too negligtable to cause this effect. Or contralily, would the light from OGLupiter be too Powerful?
(Assume the person a has a space suit)
At what point would a human being feel the negitive effects of gravity from Jupiter? OGLupiter?
For example, if we were on one of Jupiters moons, would the pull of Jupiters gravity have its way with us? Fatally? Or would the moon have more gravitational control over us?
What if we were in the vacuum of space? When would the gravity from Jupiter then have negitive effects on a human being?
(I’m not too worried about OGLupiter, I’m sure a person would burn up before OGLupiters gravity would kill them).
It wouldn’t be bright enough to noticeably light up other planets.
You’d feel the negative effects if you were standing on the surface, otherwise you’d be in free-fall. Astronauts experience this effect all the time; despite the fact that they orbit in a region with more than 90% of Earth’s surface gravity, they’re in free-fall so they don’t feel it. Same thing if you’re standing on a moon. You’d feel the moon’s gravity, but you and the moon are falling around Jupiter.
Always wondered what would happen. Only now (6:00a.m. on Sunday, years later) decided to find out. Best article I found on this question. Thanks, The Physicist.
As an FYI, this idea (Jupiter becoming a star) was the plot of the Arthur c Clark novel 2010 Oddessy Two. In the book/movie, aliens use some sort of technology to start up fusion on Jupiter.
In the end of the book, everything worked out OK as far as the earth goes but I haven’t read the third in the series, 2063, to see if there were any long term effects 🙂
Great topic though!
@Aaron: Read it. There are some interesting ramifications. There is also a 4th book, 3001.
Also, @ The Physicist RE your June 15th, 2011 response, I am sure that by now you have heard about the planet found orbiting Alpha Centauri recently. Goes to show, the Universe is a weird place.
Is it possible when our sun dies and takes out the inner planets it could shoot off enough matter to ignite Jupiter?
An entire article, complete with many comments, and not a single mention of Arthur C. Clarke’s “Odyssey” novels? Color me shocked! I believe it’s the third book, “2061,” in which this exact event happens: Thousands (probably more) of the Monolith structures suddenly appear around Jupiter, causing it’s mass to go critical and ignite to become a new star called Lucifer. Realm of Science Fiction, yes, but still a very nifty concept. Glad this question was asked and answered, though! Gave me a great flashback to reading Clarke’s incredible series…
“Specifically (guess) it would cause the other planets to fall into phase lock with OGLupiter. That is, the other planets would have years that are simple fractions of OGLupiter’s year (“2/3″, “2″, “1/2″, etc.).”
Exactly wrong. There are gaps (called Kirkwood Gaps) in the asteroids at precisely those orbits that are simple fractions of Jupiter’s period. For an asteroid with a period half that of Jupiter, every other orbit it gets a tug at exactly the same point in its orbit, soon perturbing it into a different period. The same mechanism creates the Cassini Division in Saturn’s rings.
One phase lock that IS stable is 3:2, for example, Pluto and Neptune. Such a period keeps Pluto locked in an orbit that avoids Neptune. A lot of Kuiper Belt objects have periods similar to Pluto’s and are dubbed “Plutinos.”
Damnit Aaron! LOL i was just thinking what an excellent plotline to use in a Scifi flick. Aliens use graviton fields to pull the asteroid belt into Jupiter, igniting said Star and dominating Earth.
@Roger
I did!
Turns out it’s about where you’d expect; ludicrously close to alpha centari b at about 4% of what would be the Earth’s orbital distance, so the other stars’ gravities can be pretty safely ignored.
Almost certainly not.
Jupiter is so far from being a star that it would have to fall onto a new, different planet, ten times as big to even be part of a candidate.
Today I’ve watched something very scary. The Jupiter has stole his moons from other planets, as Mars. Now it would slowly (or progressive faster ) take our Moon !
Is this really possible?
Our Moon is very, very slowly drifting away. If it managed to escape, it would probably find it’s way into orbit around the Sun, or just fall into the Sun. There would be some extremely small chance that it would find itself in orbit around Jupiter, but luckily for us the solar system will be wrecked by the Sun’s red giant phase (in about 5 billion years) which will happen long before the Moon can escape Earth.
I understand that may be only conjecture and speculation, but is it really possible one of the moons of Jupiter may have been a moon of Mars ?
Pretty unlikely. Once something is in a stable orbit (like a moon around a planet) it tends to stay there.
Of course, I could easily be way off. Do you have a reference?
I have no reference. Yesterday I watched a science film. Was told that Mars had the misfortune to be in the “wrong place” between the Sun and Jupiter. Gravity and magnetic poles of Mars were “destroyed” by the Sun and Jupiter. This “bad place” is approaching very quickly to Earth’s orbit.