Based on the inverse correlation between star size and frequency, this doesn't surprise me at all.
It seems like there is an obvious further inference to make - people have debated whether life originated on earth or not. Given that the vast majority of planets do not have a star, and given that we know there are chemotrophs even on Earth that prove it is possible to live without a sun, it seems overwhelmingly likely that life came from one of these rogue planets that was large enough to retain enough heat underground for the evolution of life over the first few billion years of the universe. That would also neatly explain why evidence of life appeared so soon after the Earth became solid.
If you're a fan of Moore's Law and the Singularity, you'll love the reasoning of backtrapolating the exponentially increasing complexity of life over time... to get 0 well before the formation of the earth https://www.technologyreview.com/s/513781/moores-law-and-the...
That's exactly why I was on the side of panspermia already. But the number of rogue planets makes a nice independent path to the same conclusion.
An interesting question to me is - if the Earth was seeded with life, does this mean we will find life elsewhere in the solar system, because they were too, or does it mean we will not find life elsewhere, because a rogue planet collided with proto earth in a very unlikely event, and the rest of the solar system (or at least the potential life supporting objects) came out of a sterile nebula around the sun?
Uncontacted tribes in the Amazon likely wonder the same thing. It's such a big Earth, yet only a few hundred humans are known to exist.
Why are there no other detectable signs of human life, like smoke signals, territory markers, or emissaries from any more but a handful of other tribes? Surely if advanced humans existed, they would have contacted these tribes by now, to share technology, discoveries, and medicine. Yet they haven't.
If they're not aware of any other humans (let alone all the cities out there) then they're likely not aware of the actual size of the earth. Perhaps they only consider it in terms of the surrounding territory.
I understand the point that we might be too backwards to see the signs of hyper-advanced civilisations, but how is it that _all_ the other civilizations are super advanced to the point that any trace they leave is impossible to understand?
And, won't uncontacted tribes in the amazon have seen airplanes and such?
A main component of the paradox is time, but this paper solve that. Life existed from the beginning, but only now has become complex enough.
So, we don't see or hear artificial signs in other galaxies because light is from the times when there was not complex life in the universe.
Now, we only have to solve why we don't see or hear artificial signs in our galaxy. But the problem is not so perplexing because we are talking about one or two million years.
If, for instance, a big part of the galaxy is bad for complex life (after all, we are far away from the center and that could be relevant), Fermi's paradox is solved.
What are the odds that our life is the first that has reached sufficient complexity to be able to communicate within our galaxy?
Given that there are 100-400 billion stars (and even more planets) just in the Milky Way: Pretty much zero.
The problem has been always the temporal scales. But if you change that, the odds are not so bad.
If all the civilizations started more or less at the same time that us, it's not so weird that we have not found anybody else. If you add some other factor (maybe civilizations are only possible far from the center, so there is a big spread between them) the probabilities improve.
It also would mean interesting times ahead for humanity.
I appreciate a good reason to think deeply as much as the next person ... but odds are just that, odds. If we were the result of some freak black swan event that kickstarted "life", the odds of it happening are irrelevant ... because it did.
To be clear, I'm not saying that's what it is ... the fermi paradox is a great thought experiment. But let's just keep things in perspective. Low odds don't mean something won't happen, just like "true random" doesn't mean the same song can't/won't play 10 times in a row ;)
The troubling thing about the Fermi paradox is that the Great Filter may still be ahead of us.
As in, the universe may be littered with the ruins of single-planet civilizations slightly ahead of our technology level. We may have observed and cataloged many such planets, failing to notice the ruins.
Dark Matter ~5*10^53 kg 26.8%
Dark Energy ~1.3*10^54 kg 68.3%
Undiscovered ? ?
We are only made up of < 1/20th of the universe's matter budget, and at that, most of Ordinary Matter is in stars and black-holes (we think). There's not a lot of matter out there (as a percent) left for life to be made of. As for the majority of the budget? Well, we know dark matter falls down ... that's about it right now (kinda). And Dark Energy? Yeah, it makes things fall up. It's ok, makes no sense to anyone else either. I put 'Undiscovered' there, as it seems we are making discoveries about the universe at a pretty rapid rate these last few centuries, so this budget is likely not even close to the real thing.
Also, people talk a lot about not meeting aliens, but just talking to them. Based on the fact that we have little/no idea how Dark Matter and Energy works, and we only really use radio signals (when funding permits), it may be like trying to whisper at the Queen of England while standing in Norway; a telephone would be much better.
3) Life may be so abundant in the universe that it's not worth talking or meeting up with. What would you say to a single mayfly if you could talk to one on it's level? No scientist or other person has bothered to try, and I think there's a good reason for that.
If you look at probability distributions rather than single estimates for every term in the Drake Equation then the absence of visible aliens isn't so unlikely.
And just the existence of life doesn't mean there's complex life. We don't have a firm lower bound on how long life took to arise on Earth after we got liquid water on the surface but it can't have been more than 120 million years. Photosynthesis, mitochondria, and other innovations allowing for complex life like you and me took way, way longer. I made a diagram for a blog post here:
I think a lot of answers have existed for that question.
In the context of this thread, lets say you are a species which stepped out of your planet, there are plenty of asteroids, and even planets lying around you can mine for resources. You settle billions of your kind in space. You are not running out resources and have no motivation beyond research and science to venture out a little far.
Would you, such a race, want to travel interstellar distances? You would travel far distances by organic growth.
Also its likely how old the universe is anybody who didn't kill themselves to extinction, is likely at our phase of development. And is likely asking the same questions as us. Those beyond our phase of development are hiding for a good reason.
No. Assuming this specific paper's thesis, that is the conclusion. There exist other arguments not based on this specific paper's thesis.
Of those, I find plausible the observation that as we tame the world to suit us, we shrink. Cities, civilization, supermarkets, products, TV, internet. By this trend, we'll live in dream terranes before long. (BTW as people get richer, reproduction gets less).
But we'll need power, and eventually a dyson sphere to capture all the sun's light - perfect for an inward-looking, closed-off people! Then what, I'm not sure. Perhaps long before that, we won't need other suns; we'll have artificial suns (controlled fusion).
That's what happens to everyone else: as they grow in technological sophistication, they get better and better at directly meeting their own (previously evolved) needs.
Personally I think the answer is anti-natalism. Once life gets more intelligent it takes a relatively short time (compared to the age of the universe) to get to the point where they realise it's unethical to create new life and choose to go extinct.
As a result, intelligent life around the universe only exists as short 'blips', being around for too short a time to ever meet other species.
It sounds more like anti-natalism is your personal philosophy, and you make the same assumption the holders of most philosophical, ideological, and religious positions make: sooner or later, everyone else will realize to be true what I realize is true.
The history of man suggests otherwise. The more our civilization progresses, and the more the population swells, the broader the array of philosophical positions those within the civilization tend to hold. We have no evidence for everyone eventually coalescing around one 'right' belief set.
History is also littered with non-reproductive sects, like the Essenes, aesthetics, or, today's answer to these, anti-natalists and child-free individuals. These groups don't tend to be very good at passing their belief systems on to new generations however, as one might expect, and they don't tend to last particularly long once they've emerged on the civilization scene.
The default for unintelligent life is to survive at all cost and fill every niche. You're suggesting that intelligence flips that purpose so that every sentient species eventually becomes depressed suicidal existentialists?
I'd put it even stronger, especially in this context where we contemplate radically simpler origins of life, that mightn't be "alive" by standard definitions (like viruses), and yet are steps along the way to sufficient complexity to be "alive": that life (in this context) is reproduction.
Seeing the wide spectrum of intelligence and education that humans manage it's hard for me to believe we'll ever reach a point of uniformity as a species were something like self-imposed extinction would be plausible.
An honestly held belief that their child would have a miserable, depressed, ill life I could understand - especially because those traits can be heritable. I can also understand sour grapes. However the other arguments seem very ill-motivated.
> An honestly held belief that their child would have a miserable, depressed, ill life I could understand
There's always a risk of that, unless you can 100% guarantee this won't happen you're basically gambling with another person's life. I don't think you have the right to do that.
That goes below a discontinuity, 256 base pairs is well below the smallest organism ever observed. A single gene is on average around 10^4 bases, and the simplest organisms have around 10^3 necessary genes. Life below 10^3 base pairs may not evolve at the same speed. It's certainly not safe to talk about it in terms of base pairs, in that era there might not have even been any.
...today. Life was simpler back in the day. For example, RNA world. This more primitive life might not survive more sophisticated life. (thougn it's also possible it's still around, but we haven't noticed it; or haven't recognized it as life).
IDK if small enough, but viruses are simpler.
If it can reproduce - e.g. a short strand of DNA or RNA or even something simpler - it could form the beginnings of "life" as a precursor, even though it wouldn't meet our current definitions of "alive".
There's theories of fatty spheres being the first "cells" (really, "kinda sorta cells").
I'm not discounting the possibility of life on Earth originating from somewhere other than Earth. However, why would the early conditions of Earth not be sufficient for life to begin over say any other object in space with the base elements for life?
How life began is obviously still an unanswered question, but if the conditions for self replicating molecules were sufficient early on for Earth, I'm not sure why billions of years would be needed for life to form versus several hundred million years.
Earth needed ~ 2 billion years for life to start. Frequent solar winds - especially in the first few billion turbulent years of the universe - basically sterilize planets and the whole 2-billion-year counter gets reset to 0.
Planets that exist without a solar system, but do retain sufficient heat, might have been out of solar winds harm ?
Life appears to have started on Earth remarkably soon after the creation of the planet and the subsequent formation of oceans - ~130 million years by some estimates:
I'm by no means well informed on these topics, but I'm unsure where you're getting your 2 billion year estimate. Furthermore I thought that Earths magnetic field shielded from solar radiation, and additionally that there's a significant amount of radiation in space anyways.
Further questioning I have though is, does solar radiation penetrate through ocean water?
What radiation is between solar systems or what rogue planets would likely encounter, and how that effects single cell life, amino acids, organic compounds, and any other building blocks to life?
>>Further questioning I have though is, does solar radiation penetrate through ocean water?
Barely. 10km of water will shield you from almost any amount of radiation, and we know of life forms which live at those depths, so they could have developed even when Earth was completely bathed in radiation.
I generally don't like the assumption that life had to come from space because we don't know how life is created and it appeared so soon in the history of Earth. That is certainly a possibility, but it also possible that creating life from chemistry is easy. Just because we haven't figured it out yet doesn't mean it is hard. Obviously figuring out how it works is hard, but the mysterious mechanism may be simple.
One problem I have with pan-spermia is: Why is there only one tree of life? Not several independent trees. If life evolved in one of the exo-planets, is not possible that several independent forms of life evolved in several planets and some ended up on Earth.
The individual nucleobases (cytosine [C], guanine [G], adenine [A] or thymine [T]) are made from the 4 most common elements, and appear to be modestly simple molecules. Is it so unbelievable that they naturally occur like methane or sodium glass?
One tree (us) either appeared first and dominated resources, or we wiped our the other trees. Evolutionary forces work at levels above species. Two trees can compete with each other.
If this happened it did so at the microbe level. Physical evidence would be extraordinarily difficult. If we did find evidence of another tree it would be so 'alien' to our tree that might mistakenly call it extraterrestrial.
And since panspermia is necessarily done with microbes, they would get outnumbered and munched by our microbes if they arrived after our tree dominated our planet. Unless other planets happened to give birth to hardier, more virulent microbes, then welcome Andromeda Strain.
I also don't subscribe to panspermia because first local origin must be reasonably proved unfeasible, but playing devil's advocate ¿what if our life tree outcompeted the others?
That's certainly possible, but not likely. Life began on Earth almost as soon as it was cool enough to do so, so we would expect to see life pop up over and over again. And it's highly unlikely that they would all get wiped out.
> life appeared so soon after the Earth became solid
It took hundreds of millions of years, possibly up to a billion years, for basic life to form on Earth. I would say that is not "soon"; it's a really long time.
The obvious response to that is, yes it seems like a long time, but it's not much on geological time scales. But it feels to me that there's an implicit circular argument here: the whole reason that geological time is measured in terms of such huge spans is because it took life such a vast amount of time to get to the point where humans exist to discuss it (understandably).
> continents won't have fossils if they are under frequent bombardment.
Right, but if giant bombardments completely boil away the oceans and atmosphere to rain liquid rocks back down on the surface, there very very likely won't be life, either. So the claim is not just that "fossils only go back to X" but that X is so close to the end of the giant bombardments that there's almost no time left (geologically speaking - maybe 10-20MY) for "life but no fossils yet".
> It took hundreds of millions of years, possibly up to a billion years, for basic life to form on Earth.
This is a common popular misconception. See something like Simon Conway Morris's book Life's Solution. There is evidence that life existed on earth almost as soon (geologically speaking) as the early bombardment stopped repeatedly boiling away the entire oceans and atmosphere, within something like 10-20 million years. Thus, all the interpretation about the implications of that.
But that's mostly because humans aren't an achievement of "life". We were never a development goal of "life" nor does the universe care very much about us - even if we built megastructures directly harnessing the energy of black holes and stars.
If current knowledge is remotely correct, heat death will happen, no matter how immortal Homo deus will become. The quarks are against us.
And if complex systems theory teaches us anything then it would be preposterous to assume any ultimate superiority in understanding the universe on our part.
Who knows who wrote crazy alien versions of Hacker News posts 2 billion years ago in one of the other couple of thousands of galaxies seen in Hubble Deep Field alone...
Humans are really just an example, I regret mentioning it. All significant developments in life (e.g. multi-cellular lifeforms, post-Cumbrian explosian animals) took hundreds of millions to billions of years.
Or the consequence of great intelligence is an evolutionary dead end. What if intelligent life becomes smart enough to destroy itself, but doesn't survive quite long enough to use that intelligence to save itself.
Interstellar travel now seems a lot more hazardous than it did before. To quote one of my TAs in college, "it's the stuff you can't see that gets you" ...
People tend to forget how big a cubic light year is.
The earth itself is only 0.02 light seconds in diameter, yielding a cube of 8000 cubic lightmilliseconds. Compared to the 2.910^31 cubic light milliseconds in a cubic lightyear... It's a rounding error inside a rounding error.
For light seconds, you're looking at 2.910^22 (if my math isn't wrong). That's the amount of cubes fitting between earth and moon to fill a cubic light years.
Even superplanets with 15 times the size of the earth are simply dwarfed by the sheer volume of a cubic light year.
The largest stars we found measure 73 light minutes, a cubic size of 389017 cubic light minutes. How much of them fit in a cubic light year? 346 billion.
Just to bring the inevitable pedantry, you'd want to consider the cross-sectional surface area rather than the volume, and hitting the gravity well of a planet may turn out to be indirectly fatal too.
So while I agree it's still probably very small numbers I think you may be overcooking it.
If something doesn't shine already. The only way to detect its existence is to send radio waves and see if something bounces off(Like Radar).
I guess the point people are trying to make here. If you can't see light coming off an object, then while traveling at interstellar speeds means it will be harder to spot objects until they get too close.
Not all black objects reflect radar, black holes don't reflect at all.
I think if you were to encounter a black hole, esp an inactive one, in interstellar space, you'd probably just get sucked in if you didn't notice the black disk...
If a black hole has been travelling without eating for long enough the accretion disk can disappear. If a black hole is large enough it won't form an accretion disk either as it swallows stars whole.
You can still detect the bent light around it from other stars. They would be significantly more obvious than planets, and you would actually reflect a tiny fraction of radar as it gets bent around the thing.
Which actually becomes a problem in the far future when stars have moved further away from each other in an ever expanding universe and their light output becomes increasingly dim to a space faring traveller...
Measuring gravity is hard. What you can do is measure gravity at both ends of your ship and if they differ by a lot you're currently being shredded apart by a blackhole.
A few things make me thing it's a much larger risk than 10e-16.
1. My numbers are on uniform distribution of planets. The milky way is not uniformly distributed, and I suspect this isn't either. I hypothesis most of the planets will be on the spokes, just like most of the stars are. In addition, while it is 2kly tall, there is not a uniform distribution across the height.
2. Interstellar travel doesn't involves traveling a minimum of 4 lys, and a maximum distance without being intergalactic would be about 100,000lys.
3. Your assuming instantaneous travel across the light year. In reality we would consume at least 1 year in travel time, and likely much more.
4. The amount of resources it takes to build an intersellar ship is very large. The cost of a collision is high. This doesn't change the risk of a collision, but it does change what we consider acceptable risk.
Same reason I can collide with someone on the sidewalk while the universe is expanding at tremendous speed. Over short distances, the expansion can easily be overcome by others forces like gravity or my muscles excerting force through friction against the ground. However, given enough time, there will be less and less objects that are close enough to be able to collide at all. Lots of time though, and there are already now lots of things over galaxy could never ever collide with.
It goes both ways depending on distance. Expansion is exponential (ish), gravity is inverse-square [1]. Only the few that happened to be close enough that gravity is more significant than expansion can collide.
[1] at least in Newtownian physics. The argument is geometry, so I suspect but am not qualified to say it isn’t exactly inverse square in GR.
On very large scales gravity collected mater into what look like spider webs, with vast amounts of empty space and threads of interstellar gass which can form galaxies. Those galaxies form little clumps within those threads with gravity causing them to orbit each other. However, as it's a many body problem things are not stable over very long time frames and galaxies often hit each other. This does slow down over time as there are fewer remaining galaxies in a cluster.
Quite the opposite, actually. At near lightspeed, a pea-sized rock will kill your spaceship just as dead as a planet. So you actually want your interstellar masses to be as concentrated as possible.
> At near lightspeed, a pea-sized rock will kill your spaceship
Why travel in a spaceship? If there's 100,000 starless planets for every star in the galaxy, then travel between stars on one of them instead. Build the habitations 10 km below water to avoid radiation. Travel at 0.1% light speed instead and get to the nearest star in 5000 yrs. Enjoy the journey, and slip into an orbit around the target star.
Speaking of pea-sized rocks, periodically fire one laden with electronics/optics/quantumics at the target star at near light speed and receive its transmissions for recon.
The planets will already be moving when captured. Mine them for energy and make adjustments to their trajectory so they'll enter into an orbit in the target star system. Drill a hole through the center for firing the pea-sized bullets. Using the recon from the bullets, find out more about the gravitational state of the star system and make small early adjustments to your own trajectory to compensate.
Doesn't really make any difference. There is some size of rock that's too big for your shielding, and you rather want that mass concentrated in a handful of planets than spread around.
Actually, one could refuel reactive mass by mining those planet if delta v is favorable. Reactive mass deficit is one of biggest problems with interstellar travel. Suddenly, I think interstellar travel is a bit less impossible.
The trouble is you'd need to stop, mine the mass, then accelerate back up again. If you have the fuel to stop to refuel in the first place, you don't need to stop refuel, unless there's something else you need as well.
I think that's what your parent meant with "if the delta v is favorable", like, if you move in the same direction and the speed difference isn't too absurd, it might be worth mining there.
I did no math to confirm this but intuitively it seems incredibly unlikely to hit a rogue planet if you shoot something to a star randomly. How's it any different than shooting something inside Solar system and accidentally hitting an asteroid?
Collision with planet sized object in space would be extremely rare. Even if you would travel blind it would be very unlikely that you would hit star or plant while traveling trough galaxy.
Well, if there's not much around it, it might be hard to detect it's gravitational effects.
I'd imagine you could detect it blocking a circular patch of sky more easily and from farther off than you could detect the gravitational pull on your spacecraft.
Just don't steer twords the black disc and you'll be fine.
Four ships (or a ship and three probes) arranged in a tetrahedron, where the distance between each pair is precisely measured with a laser or similar. Changes to the edge lengths of the formation show a nearby gravity gradient.
What’s one wavelength per minute if the formation is 1000km?
True, although I expect the ISM pressure to be fairly directly measurable. I wonder what the magnitude of all possible affecting things is compared to the gravity of planet like objects at various distances…
I can't help but think of how the various Star Trek series handled rogue planets... and then later on how IRL science delved into rogue planets as more of a reality than previously realized.
“It is unclear how plant life could survive on Dakala. One scene, however, shows the surface covered in the dim light of a nearby star, perhaps supplying enough energy for some form of photosynthesis. Another theory, from the Star Trek Encyclopedia (4th ed., vol. 1, p. 177), is that the plant and animal life was supported by the surface heat from volcanic vents.“
Back in reality there were popular magazines like Discover that would have flashy covers about things like ROUGE PLANETS! Mostly just sensationalism.
Some semi-unemployed Hollywood writer would be paging through these while smoking out and get inspiration for a script. That is Star Trek's scientific insight.
And I'm a trek fan. OP probably just doesn't know a lot of this stuff was "ripped from the headlines" (of popular science magazines).
I thought that the volcanic activity is a phenomenon happening only in orbiting planets, due to a number of forces that include star's gravitational one.
I dont recall the season or episode name, but there was an episode in Voyager that involved a rogue planet that was involved in some sort of ancestral hunting ritual.
This is not super recent information. There have been estimates that there are about as many rogue planets as stars since 2011. There's still a pretty wide variation in the estimate of the number of rogue planets from study to study, so the frequency is pretty uncertain. But even if the numbers are on the high side, it's not anywhere close to explain dark matter. Supposing that there are 10 Jupiter mass planets for every star, that would only increase the luminous mass of the Galaxy by 1%. Dark matter accounts for more than ten times the mass of the Galaxy as luminous matter.
Not a physicist.
If napkin calculation goes, that's 1000 Jupiters per star. Is that really improbable? There is a lot of space outside of solar system radii.
I think it would require more like 10,000 Jupiters per star to account for dark matter in the Galaxy. The issue is that these microlensing surveys put an upper bound on the number of rogue Jupiters that can be floating around and this bound is much less than 10,000 per star.
This sort of space real estate is the biggest hindrance to developing long term interstellar traveling tech.
With so many asteroids and planets lying around. There is no real motivation to travel very far distances for resources. Once you start mining the first set of asteroids and settling your race in space. You could grow organically, and at some point mine a terrestrial planet. At that point you have so many resources at your disposal it doesn't really make much sense to move out to very large distances unless for science or your population is just multiplying beyond control.
I wonder what happens to the planets in the solar system when a rogue planets gets sucked into the star (sun) ?
I mean, yeah it'd be bad if a rogue planet smashed into us, or even came close enough to mess with our gravitational pool (or the moons). but I imagine if an earth sized or bigger slammed into the sun, that we'd feel the effects of this.
massive solar flare roasting our planet alive?
a shower of ejecta from the collision that we pass through?
it changes the mass of the sun in a significant way that changes the pull it has on the planets around it?
Napkin math (aka pure speculation) suggests that unless the rogue planet hit the star directly and at an angle that could send ejecta our way, the results would be more observational than catastrophic.
The Earth is roughly 333,000 times less massive than the Sun. Think of it this way, If an asteroid hit the Earth that was, in relative terms, the size of the earth relative to the sun, it would be about 1/3 the size of Ceres. Everything on Earth would die but the other planets would probably not notice.
Given that the surface of the Sun can be treated, to a first approximation, as a fluid, an impact that was perpendicular to the surface would likely have the same characteristics of a milk drop. Which is to say a large wave would race away from the impact point and the collapsing of that wave in would eject a bit of coronal mass roughly equal to 1% of the mass of the impactor (note this makes a big, and unsupported, assumption about the viscosity of the solar corona.)
The only scary bit comes if the rogue planet enters the solar system slightly off the plane of the ecliptic and hits the Sun in a glancing blow. In such a scenario it could transfer a huge amount of momentum into the coronal mass which would then immediately begin to head away from the Sun. If the Earth were in the path of that mass it would probably wipe everything out after blowing off our atmosphere.
This wouldn't be good for the rogue planet either, which would probably enter a hyperbolic orbit and shoot away from the solar system on a new trajectory. In the unfortunate circumstance that this "coronal braking maneuver" was sufficient to slow the planet enough to be captured by the Sun, the remaining planets would get to witness periodic brushes with the Sun by the rogue planet until it had lost enough energy to fall into the Sun.
That would be mitigated if the orbit it fell into pulled it by Jupiter or another large planet which, by virtue of its gravity circularize the orbit sufficiently that it would not come near the corona on future orbits.
Let's say the rogue planet is a massive, super-cold planet. How big and how cold would it have to be to lower the Sun's energy output just enough to trigger a "Snowball Earth" scenario? Assume a direct hit.
I think the only way this works is if the planet doesn't hit the Sun. One could imagine a scenario (but the orbital mechanics don't work out) where a massive rogue planet enters into the solar system and interposes itself between the Earth and Sun, thus shading the Earth and dropping its temperature the required amount. Sort of like a month long solar eclipse or something. But at that mass it's probably pulling Earth out of its orbit so that scenario is not really very plausible.
If it hits the Sun, it really doesn't matter how cold or how massive it is (up until it becomes a brown dwarf at which point we're talking binary star interaction levels of mass).
The thing is that the Sun is really spectacularly huge. You could fit over a million earth size planets inside of it. And it is a run away fusion reactor so it is kind of like throwing frozen beer cans into a 500 acre California wildfire. Very little effect on the fire (although any embedded Hot Shot firefighters will appreciate your effort).
But things are even easier than actually hitting the Sun in this case. If you're trying to just screw up the Earth, any rogue planet that flew through the Solar system and pulled earth more than about 6 - 8% off its existing orbit should completely wreck the climate. If you were a fiction writer you'd want it to be bad enough that people could survive long enough to write a story about it or course.
Generally though any astronomical mass that would nominally qualify as a planet flying within a million miles of the Earth is going to likely trigger an extinction level event. Especially if it is off the ecliptic by some amount.
"where a massive rogue planet enters into the solar system and interposes itself between the Earth and Sun, thus shading the Earth and dropping its temperature the required amount. Sort of like a month long solar eclipse"
For our planet's distance from the sun, I have a hard time imagining how anything without self propulsion could maintain a stable orbital position to cast a shade over us for a long enough period (e.g. a month).
to a point you are right, but clearly there is some boundary, right? imagine a solid object with a mass just below the Chandrasekhar limit and a temperature near absolute zero. Don't tell me hurtling that into the Sun will make it burn hotter. And even if it would (or a smaller object) in the long run, there would at least be some period of time before the incoming matter reached fusionable temperatures, reducing power output in the short term.
Seems unlikely for fusion. Think of it from the point of view of star formation - the gas that coalesces into a ball is already super cold from floating around in space. The heat for fusion comes from gravity compressing the matter, not from the starting heat energy present in the matter itself.
So yeah, you can't really add cold stuff to starts to extinguish them - stars are made from absolute ice to being with.
ya, the steady-state temp of a star is a byproduct of its fusion process, which is directly controlled by the pressure of gravity. More mass, more gravity... the kinetic energy of the temperature of that mass pales in comparison to the E=mc^2 energy contained in that mass.
I think you just described what happens to a stellar core during a supernova. The temperature difference between the surface and core of a red giant is so large the surface might as well be “near absolute zero”.
Both the sun and the distance's involved are massive, so besides the scientific observations nothing will change. You would need something massive like a brown dwarf that's already near the fusion point to really screw up the sun
The voyage the planet takes through the solar system might drag some asteroids with it however, which could lead to some fun
I haven't done the math, but I'd be mildly surprised if there were any dangerous effects. The Sun is just so big relative to even the largest planets, and much much denser as well; I suspect that most of the ejecta thrown up by a collision would be pulled back down the gravity well before reaching Earth orbit, and the mass of a planet is so small compared to the Sun that I doubt it would alter its gravity well appreciably.
I was about to suggest this movie, but since someone else suggested it, I might as well note that Melancholia has more to do with other things than "a planet crashing into earth". It's more of an existential catastrophe than a terrestrial catastrophe.
There's an exploration of that in book 2 of the Three Body Problem / The Dark Forest. Don't remember exact details, but I think it posited the destruction of the inner solar system, mostly due to solar wind both roasting the inner planets, and slowing them down - which causes more planets to fall into the sun in a chain reaction.
That's very, very unlikely. A rogue planet passing near a star wouldn't crash into the star, it would follow a hyperbolic trajectory out of the system.
Current definition requires the object to be orbiting the Sun (and only the Sun not other stars) so by IAU definition these are not planets.
> A "planet" is a celestial body that: (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.
> A "dwarf planet" is a celestial body that: (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.
> All other objects, except satellites, orbiting the Sun shall be referred to collectively as "Small Solar System Bodies".
Yes, but it's probably rubbish clickbait. They locked me out of the site when I opted out of tracking. Good riddance and I look forward to their receiving a hefty fine from the EU for GDPR non-compliance.
Yes, I had the same issue. Selected just the minimal cookies they said they needed to run the site. Site makes you way several minutes while the "process your request". Then got locked out. Oh well, another site I can live without, but I too look forward to them getting a fine from the EU.
Yup just ridiculous. Opting out of targeted advertising doesn't mean you can't show ads. Dumbest thing really, how much more money they were going to make if I consented to ad tracking? A percent of a cent?
The title doesn't seem to embellish the article, and others are noting that the author is credible. Sorry to hear that you were blocked from being able to read it.
It seems like there is an obvious further inference to make - people have debated whether life originated on earth or not. Given that the vast majority of planets do not have a star, and given that we know there are chemotrophs even on Earth that prove it is possible to live without a sun, it seems overwhelmingly likely that life came from one of these rogue planets that was large enough to retain enough heat underground for the evolution of life over the first few billion years of the universe. That would also neatly explain why evidence of life appeared so soon after the Earth became solid.