"We" don't *really* need to worry about getting around the Galaxy. Technically, we are already on a rock-ish-ship cruising around the galaxy every 240 million years. All "we" need to do is keep stayin alive. Our current flight takes passengers a total distance of around 163,000 light years. Of course, the last time "we" were here, "we" were just the earliest form of modern mammals 240 million years ago, but that's besides the point. Technically, we just need to find a way to exit,...or hitch a ride on a rock-ish-ship heading in another direction. -Jake
That would be nice to have similar video regarding history of nearest star systems let's say for last 30 millions of years. Some are moving with us and some are not. But the whole galactic arm (Orion arm) is moving together, as the whole galaxy spinning. Around our galaxy are voids stretching to nearest galaxies (Andromeda and Triangulum around 2.5 mil ly). So you would hitch-hike still the same neighboring star systems which would alternate only in certain frequency.
I really enjoy your videos. You do a great job presenting interesting information. You are the only one who calls me a wonderful person. That is nice. Undeserved, but nice. I hope it's OK to take it personally.
Thank you for highlighting this new study. I would hesitate to call the study "accurate" until we have more observational data to back it up, but it does seem like a good "educated guess". I think the study is a welcome pushback to those people who look at the exoplanets discovered so far and conclude, based on that skewed sample, that earth-size planets in the habitable zone must be extremely rare. Good stuff. I look forward to learning more.
agreed, in fact almost all interstellar or farther space related science is still more educated guess than accurate, simple because we still know so little. For all we know the science we use could be completely wrong in a different Galaxy
You can forget most of the F type stars, too. The stars that host habitable planets run from F8 to K9. The most suitable type is K3 because the spindown time, from an initial 8-hour rotation period to a 1:1 spin-orbit tidal lock, for an Earth-sized planet in the classical habitable zone, is commensurate with the expected main sequence lifetime of the star, about 40 billion years.
Even if Earth-like planets really are this rare, it is important to remember that life isn't limited to JUST Earth-like planets. Even life as we know it could find a habitable home on things like the moon of a gas giant, if conditions are right. We are able to detect gas giants pretty easily, but the moons of those gas giants are another story. If Jupiter were closer to the sun then many of its moons might be warm enough to have liquid water and be very Earth-like. So when we discover a gas giant in a habitable zone of a star, that's really not the full story, because we don't know what sort of moons that gas giant might have, and those might be Earth-like worlds in their own right which aren't factored into this equation.
Can we just start off with finding a slug on an another planet, regardless of earth like or non-earth like. That in itself will answer a lot of questions.
Venus is out of habitable zone and Mars is too small. Both dont fit. But both are very similar to Earth, Venus is pratically a twin. We near had 3 habitable planets only in our solar system. It is mindblowing the number of potencialy Earth like planets out there, only in Milk Way. Imagine in Universe?
@@humanbass Actually, Mars possessed earthlike atmosphere sometimes in its ancient past. It lost it tho and still continues to leak it, but there's no enough data to conclude why the leak happened.
Both Mars and Venus, many studies said, had better conditions than what they have now. Venus wasnt so torrid and pressurized, Mars had even large oceans of liquid water. The "earth like" conditions are probably temporary, even here on earth (the planet was frozen for ages, to say one). However rare, in the trillions possibilities, it would be nonsense to expect our world is unique. This is a thrilling thought...
Don't forget one of the most important factors to making a planet habitable to life as we know it: A planet needs to have a magnetic field in order to shield it from deadly radiation. This likely means that it needs to have a molten core. And the presence of at least one large moon helps.
@@XpaceTrue Depends. This hypotetical moon need to be equals to our moon. Depending on type of moon, it could slow down the planet spin, stopping magnetosfere.
Not really. It is merely plugging in more accurate numbers into the paradox. The more accurate the numbers or estimates are in the different sections of Fermi's Paradox, the more reasonable should be the estimate it spits out. As speculative and error prone as it is. It is still based on what we know, and our best most educated guesses and estimations. I don't see how it makes explaining the actual Paradox itself, or about the Paradox more difficult, or indeed how it would make any answer spat out from the equation any more difficult. It is simply a newer, better estimate to put into a part of the equasion that it fits.
The fact that we have 4 Earth 'like' planets in our own solar system is just mindblowing 🤯 -Venus, Earth, Mars, Titan ... the real MVPs. The universe has given us so much.
Venus, earth and mars are formed close each other, pratically from the same region of the clould of dust that originated solar system. The composition of this three are very similiar in the begining. Its mindblowing
There's also the case to be made of how many moons harbor life out there. Perhaps more than planets considering moons don't need to be in their sun's "habitable zone"
WHY, do moons not need to be in the habitable zone? Are you suggesting a planet on the edge of a habitable zone could have a moon that would simply dip into the habitable zone enough to become habitable? I'm not too sure how that would work out. It sure would be a place of extreme temperatures.
@@martingrundy5475 I meant that a moon orbiting a planet (like a gas giant) which isn't in the zone could harbor life due to tidal heating from the planets pull
The problem is that even if you have the right sized planet in the habitable zone, you still need a rocky planet (not a gaseous one), with plate tectonics, an atmosphere (with nitrogen and oxygen), a magnetosphere (that blocks cosmic rays), and a nearby gas giant that can attract space debris from constantly hitting you. When you consider all those factors, the definition of "earth-like planets" drops dramatically.
If we are looking for planets with habitable conditions or liquid water, the age of the planet needs to be considered as well. The environment that we enjoy here on Earth today will not always be (and was not always) habitable either.
Our current knowledge says, that our planet earth was habitable for microorganisms not very long after the formation of the Earth 4.54 billion years ago. Even so the liquid water. So young planets arent the problem, only too old planets.
Yeah, and also, then chances of stars having Earth-like planets ranging from 3% to 25% is just too much of a spread for me. When you have numers so disparate, you are missing something crucial.
Also to be considered, that a lot of stars are in double or triple systems, meaning that you have two or three stars orbiting each other. Needless to say, that those conditions are NOT conducive to life.
@@RealDymondZ NONSENSE! Your silly 4.54 BYO is Satanic nonsense! Worms and vegetation produce topsoil at the rate of one inch per five years. Your silly 4.54 billion years must mean there should be 900 million inches of toposil on Earth. Earth is only 500 million inches diameter. Your silly 4.54 is a nonsense figure some fool came up with to try explain why lead and uranium are found in same deposits. Lead is one of the natural elelments GOD put in the mix of water and elements that was the sphere Earth on Day One of Creation 6,000 years ago. Some fool came up with the idea uranium decays into lead over 4.54 MY. In fact all radiation dates from The Flood 4,350 years ago and was created by super surges of piezo-electricity as the Earth granite and quartz crust was shaken by GOD! Ukranians can make new elements with super high electricity.
didn't i learn from you last week though that if we're gonna discover life, we need to be looking for goldilocks planets that are accompanied by a jupiter-like bodyguard to draw in all the cataclysm-inducing meteors & space rocks?
The Earth isn't dying we are killing ourselves by ruining it's environment.... And if we get our act together we can develop technology to restabilize our climate we might be even able to avert the looming crisis in a billion years
I think earth size and even smaller is very common, just that we got hard time to discover them. Just like we used to think our sun was small until we improved our instruments.
Maybe someday we can put aside petty conflicts based on skin color, religion, political affiliation, and what sports team you root for, and actually make it to the distant stars to find these planets.
The Moon is our kickstand. It not only keeps us from being tidally locked, it keeps us from tumbling wildly so we have a regulated 12 hour day & 12 hour night. It also keeps the ocean water moving so we don't end up in a swampy stagnant decay. It is a near-flukishly perfect ratio for the size & composition of Earth. & also very pretty to look at in the night sky.
I don't know if the size of the Moon is as important, considering any new planet would prob be expected to have a new mass, etc. But for us here, it is paramount.
I think we should ignore most stars of the galaxy, namely those in the galactic core, which is to crowded. Too many supernovae and close encounters with nearby solar systems.
The study is about the percentage of planets that are similar in size to earth, not about habitable planets. If it would be about habitable planets, you might think scientist would take the habitable zone of galaxies into cosideration.
@@RealDymondZ He isnt to far off though. If we take into consideration of the earth-like planets but as he said ignore the galactic core then we may just narrow our search on habitable planets.
Just opposite because there may be plenty of planets which may be habitable, moving around the central black hole. And numbers of such planets were not taken into account in the presented study. So the total number may be even higher.
Given those state. It would be interesting to plot how many of these Earth like planets would be based on distance to us in light years. How many would be within 5, 10, 20, 50 light years statistically.
One thing I truly hope happens in my lifetime is the discovery of life beyond earth. Even if it is something as simple is bacteria or something as primitive as single celled life. As long as it isn't some hostile aliens invading earth, lol, it would be so incredibly amazing and would make me beyond happy and excited ( I can not think of how to really describe how it would make me feel).
dogfish 33 true mate. Could die happy, knowing that there indeed is something out there except us and we are not some kind of miracle religions are trying to sell us. But im not sure if theyre gonna tell us even if they find something. Humanity is not ready for this and people would probably start to panic. Thats just my opinion
@@creativeno0b241 It would be so satisfying to prove all the religions out there wrong. I don't however believe it would be hidden from us if life was discovered elsewhere.
Next question: How many of those planets actually has a moon to help prevent tidal locking? Also, I can't say I'm thrilled to visit a planet that's 1.5 Earth masses. I'm not Goku.
Once planets that suit the criteria are examined in numbers, in the absence of a similar orbiting moon, if they consistently find no relevant oxygen quantity in their atmospheres, this would vastly change the probability calculations regarding life bearing planets in the galaxy.
Exactly Anton - "WE BELIEVE that the chance for having extraterrestrial life increases dramatically if we discover a similar planet to our Earth." - but the fact is that we have no idea, no idea at all what it can be and where it can be.
So the percentages of finding an Alien world in every FGK Star found go like this: 30% Earth-like mass object 3% Earth-like distance on a highest gambit
I bet on another Earth, Anton is a used car salesman *Anton:* “Hello wonderful person, this is Anton. And this...” _Anton pulls the tarp off of a car next to him_ *Anton:* _“is a 93 Mazda RX-7”_
What percentage of planets in the habitable zone are thought to be tidally locked? I read something recently that said most exoplanets are tidally locked. I think it would be much less likely for a tidally locked planet to be similar to earth, even if it has an atmosphere which can distribute heat around the dark side of the planet.
While there is a staggering number of stars in the galaxy, it seems like there has been some suggestion that the location of the solar system might be a habitable zone in the galaxy. Too close to the supermassive black hole could be a problem. Too far out closer to the edge of the galaxy, and there might not be enough of the right materials for a habitable planet. If there is a galactic habitable zone, that might reduce the number of potential habitable earth-sized planets. Any thoughts on that?
Don't forget about the Galactic Habitable Zone, and those stars/planets near other dangerous stars, pulsars, etc., and those in an unstable neighborhood.
banderse77 ... he’s not talking about the habitable zone around a star but the habitable zone within the galaxy itself. Our sun is located just off a galactic arm with stars some 4 light years between them. While stars in the galactic center are within light weeks of each. Any planet orbiting there would be subject to deadly radiation along with gravity tidal forces. The galactic arms are no safer, the stars are close enough that if the radiation doesn’t get you, the surrounding stars would constantly disturb the Oort Cloud, tossing planet life killing asteroids and comets our way. With 95% of the stars within the galactic center and spiral arms ... you have to begin the calculations from there. So instead of looking for earth like planets, we should first be looking for sun like stars within these galactic habitable zones. Then we can look for earth size planets around these sun like stars within the Goldilocks zone!??
@@JimCOsd55 sorry my phone is glitchy, meant to put this response on a different comment. Some guy wanted to know the how earth like planet was determined.
What would the geology be like on these Earth 2.0 types. Would you get plate tectonics, would quakes and volcanoes be worse. How would the oceans and at atmospheres behave. Would intelligent life be possible on these planets?
Leoben it’s generally accepted that water is a necessary thing for plate tectonics, so potentially. I also suggest you google the Planetary Classification List 6.0
I'm glad they finally got off the red dwarf kick. I always said that was a non-starter. Now, if you REALLY want to increase your chances of finding a habitable, earth-like planet, concentrate on those stars with a metallicity similar to our sun. Find a star like the sun with the same or greater metallicity, it's almost a sure bet there will be at least one planet orbiting around it that is similar to earth. The only question is, will said planet be in the right location. From that point on you should focus on those suns that are the same general age as our sun, and VOILA. Good chance somebody is looking right back at us.
If theres animals adapted constant day or constant night or constant twilight. Even a civilian with scientist. Would consider their planet rare conditions for life and think earth to unstable for life constantly shifting between night and day
If we look at it from a strictly real estate perspective, we could focus on earth-sized planets in the Goldilocks zone and terraform. Or build a habitable structure from local materials, assuming a commonality in our asteroid and Kuiper belts. Think DS9, then supersize. A system might not start out Earth-like, but it doesn't have to stay that way. Even without such drastic (currently non-existent) tech, we can build sealed buildings (maybe even domes) and take our atmospheres with us. That alone is enough to make Mars a winner. We don't really *need* the Goldilocks zone, but hey... location, location, location!
Hi Anton, really interesting stuff. I like how you explain really complicated cosmic phenomenon in laymen's terms. I wonder if you can do a follow-up video that takes the theory once step further (using the Drake equation?) to show how many earth like planets in the habitable zones of FGK stars have liquid metal cores (which enables the creation of atmospheres by blocking the radiation bombardment of the nearby star) and which have water and which have large Jupiter types planets to absorb most (not all) large asteroid strikes and what percentage have survived long enough for cellular and biological evolution for millions of years? This would reduce the final number of earth-like planets with intelligent life to a number probably closer to 100K in the galaxy. That was just a wild guess. Thanks!!
So from the number of suitably sized planets, next must consider how many would have liquid water on their surface ? Venus has none as too hot, Earth has and Mars once did but too small to maintain magnetic field and thus prevent solar wind from stripping its atmosphere/water that it once had. Well that's a conservative 1 in 3 from our solar system example. Then what if a large moon is needed to generate regular tides and changing chemistry at shorelines of wet/dry cycles with lots of energetic UV to power reactions (but which does not penetrate deep into water) and muds at the shoreline acting as possible substrate/catalyse? Earth/Moon is not quite unique for similarity of sizes (Pluto/Charon too) but most planetoid collisions just create larger planetoids - its how all planets form. Whereas having just the right sizes for Theia colliding with Gaia (the forming Earth) without entirely shattering the two (as likely with the Asteroids) or merge, seems an unlikely limited scenario. Combination of water and large moon seems the more refined search we would wish to explore further.
The energy to build a wormhole large enough to pass through would take energy equivalent to the mass of Jupiter. But so much space to build build out space . Could there be power generators that can do just that
This however doesn't go into many other limiting factors that also very likely have a profound effect on the development of life: the presence of a large moon (tidal forces and stabilizing axis tilt), low rotational speed of the parent star (as Anton talks about in a previous video, this can be a very important factor due to the rate of solar flares, and stars that rotate as slowly as the Sun are very rare). And not to forget that many if not even most of these systems could be too early (or late) in their development to support life, especially complex life. You can very easily extrapolate filters making finding anything a thousand fold (or more) less likely. Whether that's accurate or not remains to be seen, but it should be considered when talking about the chance of finding life.
from a wonderful person: why do we fantasize about planets that don't exist, and that we can never get to anyway? there is only one earthlike and we are living on it. let's save it.
It is correct to say earth-sized. The planets are often tidally locked or do not have sufficient protection against solar flares; our star is pretty quiet, for that matter. I think our moon plays a crucial part in that too. So, it does not make any estimation, on the potential for life on these planets. And as far is I was told, the further towards the center in our galaxy, the less hospitable space becomes, for life. It might be, that the milky way has a goldilocks zone too.
There are 327,627,943 Earth sized planets in our local star cluster. I've been too all of them. Trust me, most of the habitable ones are real dumps. One isn't so bad, but the days there are only 18 hours there, so I came here instead.
I sometimes think the answer to interstellar travel and instant communication is hidden in quantum entanglement and erasure, borrow from the future, pay back the past? Maybe the ship can occupy the vacuum of borrowed future time?
Wether our galaxy has 600 millions or 10 billions earth sized planets, they have yet to be habitable! The only form of life outside of earth that we know of is bacteria, notably in Venus' atmosphere. Finding another planet hosting life in our own galaxy might be impossible even if we try to find one that has something as simple as deers, bears or camels on it. I do believe there is life elsewhere in the universe, but within our own galaxy seems unlikely considering all the elements needed for it to happen!
@@motan7864 I remember that from a PBS video like 2 years ago. I don't remember details but they detected microscopic life in evaporating water from the planet.
And some people say aliens don’t exist... About 7 billion earth like worlds in the Milky Way alone, and guess how many galaxies are out there in the universe.
ineedmoney121 in a serious note, 12 is nowhere near that. That like 0.000000000000000000000000000000000000000000001% of all the galaxies in the universe.
600 Million to 10 Billion potential Earth sized planets in the habitable zones of FGK type Stars, potentially having water, and possibly bearing life. If life, have they stood up, built stuff, or left their solar system? So pretty to think about.
Huh, 600mil, and if there is indeed a goldilocks band to the galaxy, one could guesstimate about a 100mil possible earth like planets and what would be the probability of those forming life or at least be conducive for life to exist...?
Well, that blows every sci-fi universe out of the water. I think we will master FTL travel some day and travel to such planets. But we will definetely be surprised of what we find there.
@@YU-zj2ge Many star systems have big planets in certain range of distances from the star. They are probably most common. While the Earth's moon is rather special case so number of such planets in habitable zone will be low, I would consider thousands?
@Sammy Smith Maybe. But Earths's moon is special with its big size. Usually moons are smaller in relation to their planet... Searching for moons around exoplanets will be probably task for more distant future - I'm not sure if e.g. JWST or ELT will both be capable of viewing nearby star systems planetary moons... although their planned possibilities are overwhelming.
@Venc Dee You are correct in that Earth's moon is very unusual in how big it is in comparison to it's parent planet. *_However,_* don't forget that Earth's moon is also very unusual in how *light* it is in terms of mass, compared to its diameter. Studies suggest it has a much higher percentage of titanium than other rocky solar bodies. Some even suggest it's hollow. If Earth's moon had a mass *typical* of other rocky moons, it'd be *_much_* smaller in diameter.
@@XpaceTrue Excellent idea. I assume that the Moon may be hollow, what I'm not sure is whether the cause is *natural* (i.e. big metal asteroid or protoplanet mass melted and evaporated partially then frozen in some form of mushroom structure) OR *artificial*, done by aliens some billion/s years ago. All this should be a matter of research activities that stopped almost completely some 40 years ago, along with the censorship of photographs and hi-res maps... If other planets' moons are smaller with similar mass and distance they should work the same way as Moon, therefore yes such an arrangement might be more frequent everywhere including nearby star systems.
A lot and I mean a lot of things have to fall into place for advanced life, but there is 200 billion chances for those things to fall into place again. The numbers are just to great. And those 200 billion chances are in our galaxy alone.
So now we have the vaguest idea how many earth-sied planets may exist, how possible is it to know which of them may support life, and then could we explore them?
We could explore them if we could somehow get close to the speed of light, like he said the closest star is 4 light years away so even going to that star would take more than 4 years
Quote "Small steps Ellie small steps" : The parker solar probe will reach 450.000km/h that's from here to the moon in roughly 45 minutes with help of the gravity from Venus and the Sun. With that speed it takes approx 1700 years to reach proxima , while that's still way to slow obviously It's a far cry again from the Voyager probes who would take roughly 40.000 years to reach it if it flew in that direction. But if you can go from 40.000 years to 1700 years flight time in 45 years it gives hope we can continue who knows if we can send probes around the year 2060 that can reach it in 10-20 years.
Is Mars considered one of these qualified planets? If so there are two planets in the solar system that could grow life no? What are the odds that there would be two planets like that in any star system??
Didn't I just watch a video last night or the night before saying that it was extremely rare that a gas giant would be out as far as jupiter but jupiter had a head on collision that took it out that far. Normally gas giants are close to the star so wouldn't they hog the habitable zone spewing out radiation and making the inner orbit more dangerous with the extra gravity and dislodging of planets. It makes sense that gas giants normally form close to the star as the material is more abundant as you move towards the star and thinner at a greater distance so you'd expect planets to normally form big close to the star and small as you go out to the edge but maybe the Jupiter collision caused some sort of disruption in our system. Curious how these hot jupiters are calculated into this. What would happen to the Earth if Venus's orbit was actually Jupiter and Mars was actually Saturn or maybe even closer to us than that. The universe is old enough that many technological civilisations could have evolved and travelled the cosmos leaving a record of their movements etc but we have nothing definite to confirm th is. Just feels like even if life is very common, technological civilisations are extremely rare to say the least and we could be thousands of light years away from another technological civilisation. Statistically it could be as rare as 1 such civilisation for every 8 galaxies. The current evidence seems to dictate that other technological civilisations are extremely rare to say the least.
Any ship built for that long of a journey needs to be able to pick up interstellar dust. Better to be built like a blue whale than a great white. Also to keep your options open you should have chemical rockets and ion drives. A thorium liquid salt reactor would give you a constant supply of xenon. The interstellar medium would provide hydrogen.
You can shrink the numbers down further by accepting that only 1 of the 3 planets in our own solar system, in the potentially habitable zone (Earth, Mars,Venus) have liquid water on the surface. Despite Bayesian statistical analysis we won't know whether this is rare or not until we find another such planet with surface liquid water.. Also, our own planet was once a frozen snowball Earth despite being in the habitable zone, so another factor is timing because it seems likely that planets don't remain in a habitable state continually or indefinitely. Another factor may be how common it is or not for planets to have an iron core with a robust magnetosphere?
Roughly 80 percent of those sized planets - or any kind of planet actually - are highly probable to be too radioactive to have any sort of life. The levels of which are off the charts the closer you get to the galactic core.
Before 1996 when the first exoplanet was discovered many people argued that maybe we are special because we dont know if exoplanets exists and now we know that 70% of stars have planets, with alien civilizations will be the same wben we could observe the atmospheric composition we will find them.
How do scientists know the position of a star? How do they know if they are looking at the North, south pole or their equator? Are all stars positioned so we can see planets passing in front of them?
>> Let's wash the fecal matter off our own walls first, before we start slinging it all over someone else's walls. You know how we love throwing our sh*t arround---it's one of our greatest accomplishments. Yeah, other planets call us the eff-ing sh*t slingers.
Great video! It's amazing that the closest potentially Earth-like exoplanet is just 12 light years away.
The Exoplanets Channel it still far
@@sweetmyth2537 but compared to the rest of the universe, its right next door
Proxima b might be habitable if it has a huge magnetic field
Isaac Arthur has a video ("Mega Telescopes") on being able to see their surfaces clearly with the use of continent sized space telescopes.
Sadly 12 light years is still a long way to go with current tech.
"We" don't *really* need to worry about getting around the Galaxy. Technically, we are already on a rock-ish-ship cruising around the galaxy every 240 million years. All "we" need to do is keep stayin alive. Our current flight takes passengers a total distance of around 163,000 light years. Of course, the last time "we" were here, "we" were just the earliest form of modern mammals 240 million years ago, but that's besides the point. Technically, we just need to find a way to exit,...or hitch a ride on a rock-ish-ship heading in another direction.
-Jake
That would be nice to have similar video regarding history of nearest star systems let's say for last 30 millions of years. Some are moving with us and some are not. But the whole galactic arm (Orion arm) is moving together, as the whole galaxy spinning. Around our galaxy are voids stretching to nearest galaxies (Andromeda and Triangulum around 2.5 mil ly). So you would hitch-hike still the same neighboring star systems which would alternate only in certain frequency.
Born to live, live to die.
A planet for every person on Earth? I want one.
Thanks for the spoilers :(
Luck with the natives of yours!
OK I have one for sale : 1 000 000 000 000 000 $ ( taxes not included )
Feel free to take one. Just tell me wich one you want. With coordinates, please.
@@benrex7775 Just as soon as I arrange transportation.
I really enjoy your videos. You do a great job presenting interesting information. You are the only one who calls me a wonderful person. That is nice. Undeserved, but nice. I hope it's OK to take it personally.
Another person that gives compliments is Alpha M. :D
Thank you. Glad you like them
Waa. That was nice.
Thank you for highlighting this new study. I would hesitate to call the study "accurate" until we have more observational data to back it up, but it does seem like a good "educated guess". I think the study is a welcome pushback to those people who look at the exoplanets discovered so far and conclude, based on that skewed sample, that earth-size planets in the habitable zone must be extremely rare. Good stuff. I look forward to learning more.
agreed, in fact almost all interstellar or farther space related science is still more educated guess than accurate, simple because we still know so little. For all we know the science we use could be completely wrong in a different Galaxy
3% to 25% is too much of a spread. When you have those numbers, you are missing something crucial.
You can forget most of the F type stars, too. The stars that host habitable planets run from F8 to K9. The most suitable type is K3 because the spindown time, from an initial 8-hour rotation period to a 1:1 spin-orbit tidal lock, for an Earth-sized planet in the classical habitable zone, is commensurate with the expected main sequence lifetime of the star, about 40 billion years.
Even if Earth-like planets really are this rare, it is important to remember that life isn't limited to JUST Earth-like planets. Even life as we know it could find a habitable home on things like the moon of a gas giant, if conditions are right. We are able to detect gas giants pretty easily, but the moons of those gas giants are another story. If Jupiter were closer to the sun then many of its moons might be warm enough to have liquid water and be very Earth-like. So when we discover a gas giant in a habitable zone of a star, that's really not the full story, because we don't know what sort of moons that gas giant might have, and those might be Earth-like worlds in their own right which aren't factored into this equation.
I think they discovered water on some of those moons, could be trillions of habitable places.
Yup. Life is everywhere in the universe.
Imagine seeing Jupiter on the sky all day.
George This is why nasa is going to titan
Can we just start off with finding a slug on an another planet, regardless of earth like or non-earth like. That in itself will answer a lot of questions.
Venus is out of habitable zone and Mars is too small. Both dont fit. But both are very similar to Earth, Venus is pratically a twin. We near had 3 habitable planets only in our solar system. It is mindblowing the number of potencialy Earth like planets out there, only in Milk Way. Imagine in Universe?
Frankly, Mars is a tad too small, too little gravity to hold a dense atmosphere.
@@humanbass Actually, Mars possessed earthlike atmosphere sometimes in its ancient past. It lost it tho and still continues to leak it, but there's no enough data to conclude why the leak happened.
Both Mars and Venus, many studies said, had better conditions than what they have now. Venus wasnt so torrid and pressurized, Mars had even large oceans of liquid water. The "earth like" conditions are probably temporary, even here on earth (the planet was frozen for ages, to say one). However rare, in the trillions possibilities, it would be nonsense to expect our world is unique. This is a thrilling thought...
Don't forget one of the most important factors to making a planet habitable to life as we know it: A planet needs to have a magnetic field in order to shield it from deadly radiation. This likely means that it needs to have a molten core. And the presence of at least one large moon helps.
@@XpaceTrue Depends. This hypotetical moon need to be equals to our moon. Depending on type of moon, it could slow down the planet spin, stopping magnetosfere.
This is making explaining Fermi's Paradox even harder!
Not really. It is merely plugging in more accurate numbers into the paradox.
The more accurate the numbers or estimates are in the different sections of Fermi's Paradox, the more reasonable should be the estimate it spits out.
As speculative and error prone as it is. It is still based on what we know, and our best most educated guesses and estimations.
I don't see how it makes explaining the actual Paradox itself, or about the Paradox more difficult, or indeed how it would make any answer spat out from the equation any more difficult.
It is simply a newer, better estimate to put into a part of the equasion that it fits.
Great video Anton. Thanks
I'll be dead for a very long time when humanity will reach the closest star system.
The fact that we have 4 Earth 'like' planets in our own solar system is just mindblowing 🤯
-Venus, Earth, Mars, Titan ... the real MVPs. The universe has given us so much.
Venus, earth and mars are formed close each other, pratically from the same region of the clould of dust that originated solar system. The composition of this three are very similiar in the begining. Its mindblowing
There's also the case to be made of how many moons harbor life out there. Perhaps more than planets considering moons don't need to be in their sun's "habitable zone"
WHY, do moons not need to be in the habitable zone?
Are you suggesting a planet on the edge of a habitable zone could have a moon that would simply dip into the habitable zone enough to become habitable?
I'm not too sure how that would work out. It sure would be a place of extreme temperatures.
@@martingrundy5475 I meant that a moon orbiting a planet (like a gas giant) which isn't in the zone could harbor life due to tidal heating from the planets pull
The problem is that even if you have the right sized planet in the habitable zone, you still need a rocky planet (not a gaseous one), with plate tectonics, an atmosphere (with nitrogen and oxygen), a magnetosphere (that blocks cosmic rays), and a nearby gas giant that can attract space debris from constantly hitting you. When you consider all those factors, the definition of "earth-like planets" drops dramatically.
Always enjoy watching your videos . Thank you ♥️😸
Thank you Anton, love these shows ..
So for the past week I've been seeing your vids recommended before bed and it's a great so I had to subscribe
If we are looking for planets with habitable conditions or liquid water, the age of the planet needs to be considered as well.
The environment that we enjoy here on Earth today will not always be (and was not always) habitable either.
Our current knowledge says, that our planet earth was habitable for microorganisms not very long after the formation of the Earth 4.54 billion years ago. Even so the liquid water. So young planets arent the problem, only too old planets.
Yeah, and also, then chances of stars having Earth-like planets ranging from 3% to 25% is just too much of a spread for me. When you have numers so disparate, you are missing something crucial.
Also to be considered, that a lot of stars are in double or triple systems, meaning that you have two or three stars orbiting each other. Needless to say, that those conditions are NOT conducive to life.
@@RealDymondZ NONSENSE!
Your silly 4.54 BYO is Satanic nonsense!
Worms and vegetation produce topsoil at the rate of one inch per five years.
Your silly 4.54 billion years must mean there should be 900 million inches of toposil on Earth.
Earth is only 500 million inches diameter.
Your silly 4.54 is a nonsense figure some fool came up with to try explain why lead and uranium are found in same deposits.
Lead is one of the natural elelments GOD put in the mix of water and elements that was the sphere Earth on Day One of Creation 6,000 years ago.
Some fool came up with the idea uranium decays into lead over 4.54 MY.
In fact all radiation dates from The Flood 4,350 years ago and was created by super surges of piezo-electricity as the Earth granite and quartz crust was shaken by GOD!
Ukranians can make new elements with super high electricity.
@@rosewhite--- that same god seems to like to destroy cause he's destroying 2 galaxies lol
didn't i learn from you last week though that if we're gonna discover life, we need to be looking for goldilocks planets that are accompanied by a jupiter-like bodyguard to draw in all the cataclysm-inducing meteors & space rocks?
Including a relatively large moon
How many Earth like planets in the galaxy? Twelve. Definitely twelve.
one, definitely one.
42
MegaOwn
Zero
12? That’s the revised solar system. Not the galaxy.
stuck in a dying planet.
Happens everytime 😔
lmao!!! 😄
fermi paradox brother
The Earth isn't dying we are killing ourselves by ruining it's environment.... And if we get our act together we can develop technology to restabilize our climate we might be even able to avert the looming crisis in a billion years
@@Dragrath1 yes!
@@Dragrath1 We're only doing 5% damage to earth.
I think earth size and even smaller is very common, just that we got hard time to discover them. Just like we used to think our sun was small until we improved our instruments.
We can not be the only life forms to exist. It just can't be possible. And anyone who thinks it so is just not rational.
Maybe someday we can put aside petty conflicts based on skin color, religion, political affiliation, and what sports team you root for, and actually make it to the distant stars to find these planets.
Hello wonderful Anton! Love your channel. Just subscribed.
Don't forget they need a moon oversized
Dont think a moon is needed.
The Moon is our kickstand. It not only keeps us from being tidally locked, it keeps us from tumbling wildly so we have a regulated 12 hour day & 12 hour night. It also keeps the ocean water moving so we don't end up in a swampy stagnant decay. It is a near-flukishly perfect ratio for the size & composition of Earth. & also very pretty to look at in the night sky.
Deborah Hanna Yeah but with other planets there could be a smaller moon or other things that make it habitable
I don't know if the size of the Moon is as important, considering any new planet would prob be expected to have a new mass, etc. But for us here, it is paramount.
Deborah Hanna Exactly. We need it here but other planets might not to be habitable
I think we should ignore most stars of the galaxy, namely those in the galactic core, which is to crowded. Too many supernovae and close encounters with nearby solar systems.
The study is about the percentage of planets that are similar in size to earth, not about habitable planets. If it would be about habitable planets, you might think scientist would take the habitable zone of galaxies into cosideration.
@@RealDymondZ He isnt to far off though. If we take into consideration of the earth-like planets but as he said ignore the galactic core then we may just narrow our search on habitable planets.
It seems the goal of the study was to find a rough number of planets worth colonizing. You'd think that would have been an important consideration.
I'm thinking instead of 5-10 billion it'd be more like 2.5-3 billion.
Just opposite because there may be plenty of planets which may be habitable, moving around the central black hole. And numbers of such planets were not taken into account in the presented study. So the total number may be even higher.
But will they have a magnetic field and not be tidally locked? I think their definition of "earth like" is too broad.
Meanwhile one of the alien race are searching for the moonlike moon like their home moon... And our earth is not in their calculation
Given those state. It would be interesting to plot how many of these Earth like planets would be based on distance to us in light years. How many would be within 5, 10, 20, 50 light years statistically.
Love videos on this topic
One thing I truly hope happens in my lifetime is the discovery of life beyond earth. Even if it is something as simple is bacteria or something as primitive as single celled life. As long as it isn't some hostile aliens invading earth, lol, it would be so incredibly amazing and would make me beyond happy and excited ( I can not think of how to really describe how it would make me feel).
dogfish 33 true mate. Could die happy, knowing that there indeed is something out there except us and we are not some kind of miracle religions are trying to sell us. But im not sure if theyre gonna tell us even if they find something. Humanity is not ready for this and people would probably start to panic. Thats just my opinion
@@creativeno0b241 It would be so satisfying to prove all the religions out there wrong. I don't however believe it would be hidden from us if life was discovered elsewhere.
Next question: How many of those planets actually has a moon to help prevent tidal locking?
Also, I can't say I'm thrilled to visit a planet that's 1.5 Earth masses. I'm not Goku.
That and a Jupiter and Saturn to keep the planet from getting hit by mass extinction causing asteroids.
0.5 extra g wouldn't be too bad. You'd get ripped af and you wouldn't even notice it after six months until the arthritis and ruptured vertebrae.
1.5 mass of earth not always equal to 1.5 gravity. Depends on the density too.
You gotta remember that gravity is a function of mass. 1.5 * mass = I'm on a new planet where I weigh a little under 350lbs.
sirnukesalot24 Depends on mass and density. How to explain that Uranus has a g=8.87m/s2, lower than Earth, and Uranus has much more mass.
Once planets that suit the criteria are examined in numbers, in the absence of a similar orbiting moon, if they consistently find no relevant oxygen quantity in their atmospheres, this would vastly change the probability calculations regarding life bearing planets in the galaxy.
Exactly Anton - "WE BELIEVE that the chance for having extraterrestrial life increases dramatically if we discover a similar planet to our Earth." - but the fact is that we have no idea, no idea at all what it can be and where it can be.
Great this is my content. Thank you Anton!
So the percentages of finding an Alien world in every FGK Star found go like this:
30% Earth-like mass object
3% Earth-like distance on a highest gambit
Found
I bet on another Earth, Anton is a used car salesman
*Anton:* “Hello wonderful person, this is Anton. And this...”
_Anton pulls the tarp off of a car next to him_
*Anton:* _“is a 93 Mazda RX-7”_
The future Anton will sell, 'new planets'
Hello, wonderful lifeform!
What percentage of planets in the habitable zone are thought to be tidally locked? I read something recently that said most exoplanets are tidally locked. I think it would be much less likely for a tidally locked planet to be similar to earth, even if it has an atmosphere which can distribute heat around the dark side of the planet.
Christopher Milford If the planet is tidally locked life can still exist on the day/night border
While there is a staggering number of stars in the galaxy, it seems like there has been some suggestion that the location of the solar system might be a habitable zone in the galaxy. Too close to the supermassive black hole could be a problem. Too far out closer to the edge of the galaxy, and there might not be enough of the right materials for a habitable planet. If there is a galactic habitable zone, that might reduce the number of potential habitable earth-sized planets. Any thoughts on that?
Actually, there really is a galactic habitable zone. That's another thing to consider.
Don't forget about the Galactic Habitable Zone, and those stars/planets near other dangerous stars, pulsars, etc., and those in an unstable neighborhood.
Around 5:30 he explains it.
banderse77 ... he’s not talking about the habitable zone around a star but the habitable zone within the galaxy itself. Our sun is located just off a galactic arm with stars some 4 light years between them. While stars in the galactic center are within light weeks of each. Any planet orbiting there would be subject to deadly radiation along with gravity tidal forces. The galactic arms are no safer, the stars are close enough that if the radiation doesn’t get you, the surrounding stars would constantly disturb the Oort Cloud, tossing planet life killing asteroids and comets our way. With 95% of the stars within the galactic center and spiral arms ... you have to begin the calculations from there. So instead of looking for earth like planets, we should first be looking for sun like stars within these galactic habitable zones. Then we can look for earth size planets around these sun like stars within the Goldilocks zone!??
@@JimCOsd55 sorry my phone is glitchy, meant to put this response on a different comment. Some guy wanted to know the how earth like planet was determined.
What would the geology be like on these Earth 2.0 types. Would you get plate tectonics, would quakes and volcanoes be worse. How would the oceans and at atmospheres behave.
Would intelligent life be possible on these planets?
Leoben it’s generally accepted that water is a necessary thing for plate tectonics, so potentially. I also suggest you google the Planetary Classification List 6.0
But there is always the question. If we have a confirmed finding of a planet with an environment friendly to humans. How would we get there?
Hitchhike om a Vogon spaceship.
A spaceship designed, and built by a committee? Chad's generational ships sound more plausible.
We need some revolutionary new technology. Will probably need trillions in investments.
I'm glad they finally got off the red dwarf kick. I always said that was a non-starter.
Now, if you REALLY want to increase your chances of finding a habitable, earth-like planet, concentrate on those stars with a metallicity similar to our sun. Find a star like the sun with the same or greater metallicity, it's almost a sure bet there will be at least one planet orbiting around it that is similar to earth. The only question is, will said planet be in the right location.
From that point on you should focus on those suns that are the same general age as our sun, and VOILA. Good chance somebody is looking right back at us.
Hell, even stars with gas giants in the habitable zone would suffice if those planets have earth-size satellites.
If theres animals adapted constant day or constant night or constant twilight. Even a civilian with scientist. Would consider their planet rare conditions for life and think earth to unstable for life constantly shifting between night and day
Without the axial tilt , or the orbiting satellite (Moon), or the magnetic field, and so on, complex life cannot exist or survive
If we look at it from a strictly real estate perspective, we could focus on earth-sized planets in the Goldilocks zone and terraform. Or build a habitable structure from local materials, assuming a commonality in our asteroid and Kuiper belts. Think DS9, then supersize. A system might not start out Earth-like, but it doesn't have to stay that way. Even without such drastic (currently non-existent) tech, we can build sealed buildings (maybe even domes) and take our atmospheres with us. That alone is enough to make Mars a winner. We don't really *need* the Goldilocks zone, but hey... location, location, location!
Rampant optimism- but I like it.
Hi Anton, really interesting stuff. I like how you explain really complicated cosmic phenomenon in laymen's terms. I wonder if you can do a follow-up video that takes the theory once step further (using the Drake equation?) to show how many earth like planets in the habitable zones of FGK stars have liquid metal cores (which enables the creation of atmospheres by blocking the radiation bombardment of the nearby star) and which have water and which have large Jupiter types planets to absorb most (not all) large asteroid strikes and what percentage have survived long enough for cellular and biological evolution for millions of years? This would reduce the final number of earth-like planets with intelligent life to a number probably closer to 100K in the galaxy. That was just a wild guess. Thanks!!
Thanks for an interesting video and beautiful in many ways😊
So from the number of suitably sized planets, next must consider how many would have liquid water on their surface ? Venus has none as too hot, Earth has and Mars once did but too small to maintain magnetic field and thus prevent solar wind from stripping its atmosphere/water that it once had. Well that's a conservative 1 in 3 from our solar system example. Then what if a large moon is needed to generate regular tides and changing chemistry at shorelines of wet/dry cycles with lots of energetic UV to power reactions (but which does not penetrate deep into water) and muds at the shoreline acting as possible substrate/catalyse? Earth/Moon is not quite unique for similarity of sizes (Pluto/Charon too) but most planetoid collisions just create larger planetoids - its how all planets form. Whereas having just the right sizes for Theia colliding with Gaia (the forming Earth) without entirely shattering the two (as likely with the Asteroids) or merge, seems an unlikely limited scenario. Combination of water and large moon seems the more refined search we would wish to explore further.
Very interesting video! I always enjoy your posts, but exoplanet studies interest me the most. keep up the good work.
Loved this video, really interesting!!
The energy to build a wormhole large enough to pass through would take energy equivalent to the mass of Jupiter. But so much space to build build out space . Could there be power generators that can do just that
This however doesn't go into many other limiting factors that also very likely have a profound effect on the development of life: the presence of a large moon (tidal forces and stabilizing axis tilt), low rotational speed of the parent star (as Anton talks about in a previous video, this can be a very important factor due to the rate of solar flares, and stars that rotate as slowly as the Sun are very rare). And not to forget that many if not even most of these systems could be too early (or late) in their development to support life, especially complex life.
You can very easily extrapolate filters making finding anything a thousand fold (or more) less likely. Whether that's accurate or not remains to be seen, but it should be considered when talking about the chance of finding life.
Whats the chances of getting my own planet and still have someone smash my heel with a grocery cart? High it's high
😀
from a wonderful person: why do we fantasize about planets that don't exist, and that we can never get to anyway? there is only one earthlike and we are living on it. let's save it.
None of what you said is factual
Hey Anton, what would the filter be like if we count only stars that spin as slow as our sun?
How I'd love to spend an afternoon speaking with you.
It is correct to say earth-sized.
The planets are often tidally locked or do not have sufficient protection
against solar flares; our star is pretty quiet, for that matter.
I think our moon plays a crucial part in that too.
So, it does not make any estimation, on the potential for life on these planets.
And as far is I was told, the further towards the center in our galaxy,
the less hospitable space becomes, for life.
It might be, that the milky way has a goldilocks zone too.
There are 327,627,943 Earth sized planets in our local star cluster. I've been too all of them. Trust me, most of the habitable ones are real dumps. One isn't so bad, but the days there are only 18 hours there, so I came here instead.
😂😂😂
Warp drive is coming
Submarines and aircraft were once sci-fi
We are in the horse and buggy days of space travel
I'm not sure FTL will ever be possible sadly.
"im sure we'll get there" doesn't bode for a lot of confidence, Anton. Lol jk jk
I sometimes think the answer to interstellar travel and instant communication is hidden in quantum entanglement and erasure, borrow from the future, pay back the past? Maybe the ship can occupy the vacuum of borrowed future time?
Really enjoyed this, it another holiday for me 😁
As impressive as these models are, I would caution against calling any of this accurate. We can't call it accurate until it has been observed.
Hell, we don't even know a lot about our planet.
Wether our galaxy has 600 millions or 10 billions earth sized planets, they have yet to be habitable! The only form of life outside of earth that we know of is bacteria, notably in Venus' atmosphere. Finding another planet hosting life in our own galaxy might be impossible even if we try to find one that has something as simple as deers, bears or camels on it. I do believe there is life elsewhere in the universe, but within our own galaxy seems unlikely considering all the elements needed for it to happen!
@@LilGamingYes bacteria in Venus' atmosphere? what are you smoking?
@@motan7864 I remember that from a PBS video like 2 years ago. I don't remember details but they detected microscopic life in evaporating water from the planet.
@@LilGamingYes no
YEAH! I hope we can go to one of these planets in any lifetimes soon!!
Wait...
If we each get a planet, I'm naming mine Dave.
And some people say aliens don’t exist...
About 7 billion earth like worlds in the Milky Way alone, and guess how many galaxies are out there in the universe.
12?
ineedmoney121 in a serious note, 12 is nowhere near that. That like 0.000000000000000000000000000000000000000000001% of all the galaxies in the universe.
@@ike_alexander 13?
ineedmoney121 okay now I thought no you’re just joking around.
*_Great Upload_* !
600 Million to 10 Billion potential Earth sized planets in the habitable zones of FGK type Stars, potentially having water, and possibly bearing life. If life, have they stood up, built stuff, or left their solar system? So pretty to think about.
I still love your Chanel bro,keep up the good fucking work
That's really a great news. After all, some day we're going to need to move... Our star isn't going to live forever.
@longflopy dog "We" = humanity.
@longflopy dog 😉
Hey Antonio. Got mad respect for you. I watch you so I learn but not thru my math skills. Lol
Thank you wonderful anton with providing us with much needed mathmatical nourishment! You're the best
Huh, 600mil, and if there is indeed a goldilocks band to the galaxy, one could guesstimate about a 100mil possible earth like planets and what would be the probability of those forming life or at least be conducive for life to exist...?
Life is bound to be out there.
Very interesting.
Thank you Anton! 👍
It's just so probable! Even if it's just one 'intelligent' species per cluster of galaxies, the odds are still in the 100s of millions!
An earth size planet per person. If I don't like my one, can I upgrade?
Time to play god xD
Great video!
Well, that blows every sci-fi universe out of the water. I think we will master FTL travel some day and travel to such planets. But we will definetely be surprised of what we find there.
When you say very difficult do you really mean absolutely impossible
And how many earth like size planets are there with an moon like size moon?
With stable magnetic feild with an out lying Jupiter body gaurd. Away from the Galactic core and curent sheath.
@@YU-zj2ge Many star systems have big planets in certain range of distances from the star. They are probably most common.
While the Earth's moon is rather special case so number of such planets in habitable zone will be low, I would consider thousands?
@Sammy Smith Maybe. But Earths's moon is special with its big size. Usually moons are smaller in relation to their planet... Searching for moons around exoplanets will be probably task for more distant future - I'm not sure if e.g. JWST or ELT will both be capable of viewing nearby star systems planetary moons... although their planned possibilities are overwhelming.
@Venc Dee You are correct in that Earth's moon is very unusual in how big it is in comparison to it's parent planet. *_However,_* don't forget that Earth's moon is also very unusual in how *light* it is in terms of mass, compared to its diameter. Studies suggest it has a much higher percentage of titanium than other rocky solar bodies. Some even suggest it's hollow. If Earth's moon had a mass *typical* of other rocky moons, it'd be *_much_* smaller in diameter.
@@XpaceTrue Excellent idea. I assume that the Moon may be hollow, what I'm not sure is whether the cause is *natural* (i.e. big metal asteroid or protoplanet mass melted and evaporated partially then frozen in some form of mushroom structure) OR *artificial*, done by aliens some billion/s years ago. All this should be a matter of research activities that stopped almost completely some 40 years ago, along with the censorship of photographs and hi-res maps...
If other planets' moons are smaller with similar mass and distance they should work the same way as Moon, therefore yes such an arrangement might be more frequent everywhere including nearby star systems.
A lot and I mean a lot of things have to fall into place for advanced life, but there is 200 billion chances for those things to fall into place again. The numbers are just to great. And those 200 billion chances are in our galaxy alone.
So now we have the vaguest idea how many earth-sied planets may exist, how possible is it to know which of them may support life, and then could we explore them?
We could explore them if we could somehow get close to the speed of light, like he said the closest star is 4 light years away so even going to that star would take more than 4 years
Oh no, Spinning Blue Circle of Doom!
the statistics that would go into trying to figure this out are crazy..you would have to assume alot with a high margin for error
you have to start somewhere. the margin of error will improve when more data is added over time.
number 1, you make great videos. number 2, to this topic i say, and yet there is not a stitch of evidence of intelligent life out there.
Quote "Small steps Ellie small steps" : The parker solar probe will reach 450.000km/h that's from here to the moon in roughly 45 minutes with help of the gravity from Venus and the Sun. With that speed it takes approx 1700 years to reach proxima , while that's still way to slow obviously It's a far cry again from the Voyager probes who would take roughly 40.000 years to reach it if it flew in that direction. But if you can go from 40.000 years to 1700 years flight time in 45 years it gives hope we can continue who knows if we can send probes around the year 2060 that can reach it in 10-20 years.
Is Mars considered one of these qualified planets? If so there are two planets in the solar system that could grow life no? What are the odds that there would be two planets like that in any star system??
as always very good vid
Great Study :D
That give me hope to live until we get into the most close star
Hello Anton this is wonderful person.
Based on the thumbnail, there are... 4 earths in the universe (a picture of one in the far bottom right corner)
Didn't I just watch a video last night or the night before saying that it was extremely rare that a gas giant would be out as far as jupiter but jupiter had a head on collision that took it out that far. Normally gas giants are close to the star so wouldn't they hog the habitable zone spewing out radiation and making the inner orbit more dangerous with the extra gravity and dislodging of planets. It makes sense that gas giants normally form close to the star as the material is more abundant as you move towards the star and thinner at a greater distance so you'd expect planets to normally form big close to the star and small as you go out to the edge but maybe the Jupiter collision caused some sort of disruption in our system. Curious how these hot jupiters are calculated into this. What would happen to the Earth if Venus's orbit was actually Jupiter and Mars was actually Saturn or maybe even closer to us than that.
The universe is old enough that many technological civilisations could have evolved and travelled the cosmos leaving a record of their movements etc but we have nothing definite to confirm th is. Just feels like even if life is very common, technological civilisations are extremely rare to say the least and we could be thousands of light years away from another technological civilisation. Statistically it could be as rare as 1 such civilisation for every 8 galaxies. The current evidence seems to dictate that other technological civilisations are extremely rare to say the least.
Generation ships are within current tech. However we need a lunar mining base first; too heavy to build in NEO.
The metals aren't actually a problem anymore its more of what are we going to do for fuel at this point
Any ship built for that long of a journey needs to be able to pick up interstellar dust. Better to be built like a blue whale than a great white. Also to keep your options open you should have chemical rockets and ion drives. A thorium liquid salt reactor would give you a constant supply of xenon. The interstellar medium would provide hydrogen.
You can shrink the numbers down further by accepting that only 1 of the 3 planets in our own solar system, in the potentially habitable zone (Earth, Mars,Venus) have liquid water on the surface. Despite Bayesian statistical analysis we won't know whether this is rare or not until we find another such planet with surface liquid water..
Also, our own planet was once a frozen snowball Earth despite being in the habitable zone, so another factor is timing because it seems likely that planets don't remain in a habitable state continually or indefinitely. Another factor may be how common it is or not for planets to have an iron core with a robust magnetosphere?
Roughly 80 percent of those sized planets - or any kind of planet actually - are highly probable to be too radioactive to have any sort of life. The levels of which are off the charts the closer you get to the galactic core.
But only one in one million of those planets has all of the conditions to support life. But it is still cool! 😀
Roger Kreil maybe aliens don’t need everything that we need to survive. They aren’t humans so
Before 1996 when the first exoplanet was discovered many people argued that maybe we are special because we dont know if exoplanets exists and now we know that 70% of stars have planets, with alien civilizations will be the same wben we could observe the atmospheric composition we will find them.
How do scientists know the position of a star? How do they know if they are looking at the North, south pole or their equator?
Are all stars positioned so we can see planets passing in front of them?
>> Let's wash the fecal matter off our own walls first, before we start slinging it all over someone else's walls. You know how we love throwing our sh*t arround---it's one of our greatest accomplishments. Yeah, other planets call us the eff-ing sh*t slingers.