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.
Referring to the scenario you first mentioned (a Jupiter-like planet becoming a small star), are there any known star systems with a small star and planets orbiting a larger star? Is that thought to be possible? I think a planet orbiting a binary star system was recently detected, but that doesn’t seem like quite the same thing. Thanks.
It seems a “Sun-Jupiter” would pull us out of orbit. Very slowly at first but the feedback loop should build on it’s self. And beyond that pulling Mars or maybe one of Saturn’s moons into a Earth crossing orbit. Or maybe Jupiter starts to fall in towards the Sun.
In the early days of nuclear weapons, there was an eventually unfounded conjecture that a hydrogen bomb might ignite the Earth’s atmosphere. I realize the issue of insufficient mass of Jupiter, but could a nuclear chain reaction (as opposed to the thermal heating of asteroid collisions, such as Shoemaker-Levy 9) ‘re-spark’ that conjecture. The moons of Jupiter could be close enough to benefit or even flourish from even a weak star, especially if we dig up some mysterious, flat-topped obelisk on the Moon. There is probably a down side I don’t see; reading at night would be cool and there could be a decrease in crime… though ‘light pollution’ would increase. -Dan (“armchair physicist”)
Most of the energy released in a nuclear bomb is heat. There is simply not enough energy to create a sustained chain reaction in a nuclear bomb. When calculations involving the ignition of earth’s atmosphere where reviewed, it was found that a mistake had been made, there was no chance of that happening.
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I used the Universe Sandbox to randomly make Jupiter a star. It turns out, things don’t go so well for us.
So we all know mass X pressure(impact)X large amounts of hydrogen can make fusion.. As we have determined take huge amount beyond possibilities for this to happen to Jupiter.. Although there is another version implode? If over 80% of Jupiter’s atmosphere is hydrogen, we all know hydrogen don’t need much to explode except oxygen.( correct?).. Now let’s say it does ignite but don’t burn just consumes itself..would or could this create a gravity inity (blackhole) Jupiter’s mass is big enough and its rotation fast enough to cause a gravity ripple ?
One more thing to take into consideration.. If Jupiter was big enough to become a star its gravity pull would already be disrupting the magnetic pull between planet and our sun.
That was an awesome question and and even awesomer answer. HOWEVER, I disagree with your central conclusion that the addition of an object 80 times brighter than the moon would not cause negative impact on life. 80 times brighter means that there would be no night at all for long periods throughout the year. 68% of mammals are nocturnal. And that’s just mammals. These animals would fail to hide or fail to hunt and would certainly die in unusual numbers. The ecological chain reaction of negative impact of 68% of all mammals (not counting nocturnal fish, insects, reptiles, etc.) would be massive. On the other end of the spectrum, some plants and some phytoplankton would suddenly be able grow without interruption with an object 80 times brighter than the moon shining on them all night long night. The mix of plants and sea life would change almost immediately. As go plants and plankton, go herbivors go predators,…So, I disagree, the world would change dramatically and many/all nocturnal species would struggle. Cloud formation is also very impacted by day / night cycles. If night was 80 time brighter, clouds might well form differently. Clouds = rain.
But Sean wouldn’t mean that all things would be different in beginning, at the birth of the solar system? Nocturnal species and everything would have evolved to adapt to that. We’d only know of things being the way you are describing instead of what we know now. I believe things on earth would be totally different from the formation of the solar system in your point of view.
These questions, however entertaining, are extreme hypotheticals. It is very difficult to ponder these questions because of the incomprehensibly massive scale of the solar system. Jupiter has as much volume as 1000 earths and about as much mass as 300 earths. Jupiter is so large, it is estimated that it comprises approx 3/4 of the rotating mass of the solar system (excluding the sun). Yet the sun itself consists of aproximately 99% of the total mass of the entire solar system. Jupiter is no more likely to suddenly begin fusion like a star than earth’s moon. Suffice to say that the solar system as it appears now is extremely stable, and has been for a long time.
This is totally intriguing. The first part I think the effect is difficult to say our orbit and jupiter’s around the sun differ so sometimes we would be affected with having no night others having a 2 sun during the day. I think things would start to evolve differently to take advantage of this and new species would come. It would be aw inspiring and scary. Think how humans might change eyes to accept the red light or a film over the eye that only is used the time of the year that the red light is there. some many other things wow it is just mind boggling!!!! great conversation. Thank you for the thoughts!!!!
How can there be stars found right now only 1 and a 1/2 times the size of Jupiter but it would take 80 Jupiter’s to equal a Sun maybe it’s compacted mass but it still don’t make since
A red star 80 times brighter than the moon.
we would have to change the color of railroad crossing lights, traffic stop lights, brake lights.
No one would be able to see those red lights at night, with such a bright red star.
James Gellinger, you’ve already answered your own question! (“maybe it’s compacted mass”)
Large brown dwarfs and small stars can be as much as 200 times denser than Jupiter! As a result, the smallest stars are only about 2x the diameter of Jupiter, despite being 100 times more massive.
James A Miller, it does not seem like the light from a small red dwarf would make much difference. The sun is about 400,000x brighter than the moon, so the red dwarf would still be 5,000x dimmer than the sun.
Wouldn’t this scenario put a good tug on the Earth, Mars, and the objects in the asteroid belt giving highly (relative to what they are now I mean) elliptical orbit? Wouldn’t this effect the amount of energy we get from the Sun and drastically destabilize the climate? I understand that you said that Jupiter is about 4 AU(I’m rounding these numbers) from us, but that cannot be counted as an out. Neptune was discovered mathematically, not visually because we noticed an irregular tug on Uranus’ orbit. That’s a distance of roughly 11 AU. Earth to jupiter is only 4 AU and in this scenario (or even if you don’t count the scenario of horribly named Jupiter star) the star would be 100 times more massive than Jupiter is which is much much more mass than what’s in Neptune and is more than twice as close.
Even slight variations in things like orbit path, axis tilt, and spin strongly dictate the course of interglacial periods and other aspects of climate, as well as gravity effects different geological aspects of rocky astronomical bodies. So I can see how it might not effect life if it formed, but if we were part of a binary system the Earth would be a drastically different place than it is currently and I can only imagine the chaos this would cause if this happened some how over a short (cosmologically speaking) timespan. All of this is up in the air assuming that this system would create the right conditions for life to form in the first place.
I don’t even know where to begin with the math on this, but all the planets effect their neighbors, if even by a bit.
BTW I stumbled on this fact checking a junk science page, and seriously thank you for posting this. Fascinating topic for postulating and was a great break. I’m book marking you!
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I wonder what would happen if Jupiter became a star. Jupiter’s mass would have to increase dramatically, which might have implications for our planet’s orbit around the sun.
I wonder if and how much our planet’s orbit would alter in that case….
Earth’s orbit would not be changed if Jupiter were a small star (the mass would be 100 current Jupiter masses). Jupiter and the Sun would orbit each other around a barrycenter (a common center of mass) this would be about one-half of an AU (AU=earth-sun distance) from the Sun. Earth would only be fine if Jupiter and the sun orbited this barrycenter at Jupiter’s current low eccentricity. Mars however would be kicked out as would most asteroids. Saturn’s orbit would also be unstable. This zone of instability would be from just inside Mar’s current orbit (1.6 AU) to 16 AU (well outside Saturn’s orbit). This could only be possible if the Solar system was created this way with Jupiter and the Sun orbiting the barrycenter at very low eccentricities if a small star entered our system and crashed into Jupiter and entered into orbit around the Sun it is likely that the eccentricity would be too high and that earth would be thrown out of the Solar System.
I don’t know what it means that well. Because I’m more of a math girl while i have to learn this for science. But what would happen if we were on Jupiter when it was star? Would we die?
I walked on the surface of the sun while traveling in the astral. Or I was on mescaline . Either way it was beautiful.
An interesting variation on this conversation looks into the future. Several billion years from now, the sun will become a red giant and in the process shed a large amount of its mass. Would not Jupiter be a prime candidate to grab this mass and become a small star? Also, what would be the composition of the mass that Jupiter grabbed? Hydrogen, helium, heavier elements?
We have a second sun called Nemesis in our galaxy.
@eric simmons
There have been some theories ascribing the periodic extinction events here on Earth to a planet or star on an extreme orbit. However, conclusive sky surveys over the past twenty years have effectively ruled that possibility out.
Given the mass of our hypothetical horribly named just created former-Jupiter- now-mini star, and assuming the collision with the rogue star occurred after the existing orbits of our solar system were established, would the new star cause any changes to the Sun’s orbit, or is the mass of Jupiter-the-star too small? In a binary solar system so created from its formation, the stars orbit each other. If a massive sun is later joined by a small rogue star (or Jupiter is transformed) would the original sun be affected?
Loving this discussion. I entered the original query into Google and was directed here. Good to know I’m not the only one musing about these things. Thank you Arthur C. Clarke for spurring our imaginations. Thanks too to this website.
Jupiter will become a Star after the Sun is Dead. The Sun will become just as our Moon. Planets will realign & orbit the next Star of the Solar System or be lost.
Evolution would/would’ve taken a very different path. Semi-Nocturnal creatures using Infrared spectrum vision to hunt &/or evade. Flowering plants using IR instead UV to attract pollinators. Probably the biggest impact to humans (if we ever even became apex critters here), would be on religion & beliefs. Possibly accelerate our understanding of Celestial Mechanics & another large mass to slingshot exploratory spacecraft thru & beyond the Solar System.
It is my position that only approximately 10Jupiter masses would start nuclear fusion on the smallest scale. At this mass, the planetary obits of those proximal to Sol would remain stable, as the SuperJupiter is orbiting all that mass as one unit mass. The planetary obits of of those beyond this SuperJupiter would be become extremely unstable, many of which would be thown beyond their gravitational link to our solar system.
It seems that Jupiter contains everything need to create as dwarf star. If it’s rotation dramatically slowed it would cause a dramatic collapse in density to creating immense heat and possibly fusion, or a massive explosion. Which is it, and isn’t it true that it only remains has because of its immense spin? What would be what if it simply slowed allowing a full collap
@Michael Browy
Jupiter rotates once every ten hours, which is fast, but it isn’t so fast that it makes much difference. If Jupiter were spinning so fast that the spin were counteracting its gravity we’d expect to see it very noticeably bulge at the equator. Instead, it’s almost perfectly round.
If, for any reason, Jupiter were to ignite in a self-sustaining nuclear reaction, and become a star: it would drop out of sight!
For the reaction to become self-sustaining Jupiter would have to shrink in volume — become much more dense at the core — so that the hydrogen would be pressurized enough to sustain a reaction. The amount of energy this new star would radiate would be much less than the amount of energy it currently reflects from the Sun!
>> By being awesome, … we’ve …
No. That’s a pedagogical error.
GOOD teachers want students to think of *themselves* as awesome. That helps give them the confidence to excel.
BAD teachers want students to think of *the teacher* (and associates) as awesome. That discourages them, because they can never be so ‘awesome’. They’ll quit physics and turn to sociology, basket-weaving, drugs, or whatever. But – they’ll think you’re really cool! So (you figure) that makes it alright.
Sorry, it doesn’t work. The more you tell people how ‘awesome’ you (and associates) are, the less they believe it. If you want them to regard you as ‘awesome’, you have to actually *be* ‘awesome’. That’s a lot harder than merely making the claim. But at least it has the desired effect – not the exact opposite.
So skip the self-aggrandizement. You’ll get more respect and better results. You can always go back to your current approach – empty boasts – if my way doesn’t work out.
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Jupiter is a gas supply for our sun when it starts to run out of fuel when our sun expands it will be replenish by Jupiter and saturn why there there igniting new worlds