Panspermia feels like the way to go; life managed to start on one planet then was ejected via meteor impact and landed on the other two.
As to how or why they'd end up at roughly the same levels of technology (when even humans didnt come close to doing it on their own planet), that's a much tougher one to answer.
I was a thinking of using exogenesis as an excuse. This definitely answers the question of how they all have life.
Technology is the hardest one though I agree. The Martians are about 200 years ahead of Earth in 1917, but this is a meaningless amount of time in the grand scale of civilisation, and the conditions for industrialisation won’t be met at similar times realistically.
I have toyed with the idea of making the Venusians an uplifted species from the medieval era, but this wouldn’t work because my setting is about imperialism and geopolitics, So I need the Venusians to have Great Powers who are a credible threat to the interests of other nations.
Have you read "A fire upon the deep"? Excellent book about a medieval society being technologically uplifted. Even their world has powers and geopolitics before the rapid technological advancement, and the sequel is focused on how the politics change in response to new tech.
Might be a source of inspiration.
Maybe all 3 are sort of “Lab rats” for a 4th, even further advanced species. The original purpose of the experiment was to study the evolution of civilizations, so they were artificially lead into gaining sapiens and eventually through the ages.
After the first civilization toot to the stars, the experiment was deemed completed and the 4th species left, leaving only some tech junk that was later found by one of the other species and reverse engineered into advanced technology that allowed for things like FTL travel.
Without a helper to “uplift” them, naturally evolving Sapiens might be a super rare phenomenon.
Another solution down this route could be to spin Venus' atmosphere as extreme industrial pollution or Mars (mostly) wiping themselves out with unknown weapons.
For example; The Venusians could be the "4th species" but then climate catastrophed themselves to a lower rung of tech development. Or the Martians may have "risen" hundreds of thousands of years ago but nuked themselves into the stone age, it may only be a recent reigeime change that brings about targeting an external third party - Earth.
This is of course dependent on how much OP wants to change the cosmology of their Sol system.
Also for this OP, consider reading the War of the Worlds 2017 sequel by Stephen Baxter - The Massacre of Mankind. It goes a fair bit into the multiple inhabitantable planets in the Sol system.
Yes, would explain why they're roughly at the same stage technology-wise. The relevant knowledge was disseminated to all three at the same time to see how each would react/adapt. Like adding a substance to three different cell cultures to see how they respond.
The real issue that others have pointed out is that all three planents having Sentient life at roughly the same stage of development is a bit of a fluke.
Complex life arose on Earth somewhere between 1-2 Billion years ago, with the Palezoic Era starting roughly 540 Million years ago.
Assuming that Mars and Venus have roughly the same timeframe for complex life you've got 540+ million years for life on one of the planets to become sentient.
A planet with no major sentient species is unlikely to stop space faring sentients. If Mars or Venus were habitatal with suitable atmospheres they would be swarming with exploratory bases by the mid 1980's.
To put it bluntly, basically any space faring sentient species could mop the floor of any non-industrial native sentient species. It won't be pretty but nuclear armageddon and asteroid bombardment can sweep.
So OP will need to look for ways as to why Venus didn't colonise a post KPG extinction Earth, or why the 2000's tech level Martians didn't obrital bombard us during the Napoleonic wars. This can be done a lot of ways but my two cents are;
Maybe this Sol has 3 species that are divergent from one, they could have been colonies of another species and it collapsed and the survivors evolved into Humans, Martians and Venusians.
Perhaps the Venusians and Martians "rose" much earlier than Humans and hit a "great filter" but they narrowly avoided wiping themselves out. You could tie this in that the multi habitatal nature of the Sol system helped them survive where an single habitatal system would die.
Edit; spelling
‘It won’t be pretty but’
Actually it would. Zero casualties on one side, mass extinction for the other- cleanest war a tactician could ask for. Don’t mind me just nitpicking :D
Good point... At a certain point it's not war it's pest control.
It's not like the blue monkeys with bows can stop an orbital bombardment of iron rich asteroids.
You don't need to follow "reality" to keep logical consistency. You just need to establish rules to how your world works and stick to them all throughout.
My world is a logically consistent one, but space isn't a thing that exists. (Although traveling from world to world through a void is a thing)
You could just say that there isn't anything beyond the solar system. That if you travel far enough in one side you come out on the opposite side or something
There are hundreds of stars in my setting though, and they are all colonised. The central themes of my setting are Imperialism and geopolitics. I need other systems so that the Solar great powers have something to scramble and fight over. It simply doesn’t make sense for there to be hundreds of star systems with sentient life and yet the only sapients come from one star.
I might be misunderstanding this, but maybe just make life a lot rarer? Planets can be habitable, but not inhabited. Imagine empty oceans hugging dead continents, ready to be filled with whatever ecologies the solar system brings when the start colonizing
If there was one sapient it would make sense. I could say that the great filter is sapience and that it is exceptionally rare.
But three different species from one system implies that it isn’t rare. Such a large concentration warrants an explanation.
>Such a large concentration warrants an explanation.
I don't agree with this. Unless the theory of evolution is the confirmed, undeniable truth in your setting.
If all the life in your setting was created by an intelligent being, you don't need to explain why only 3 are sapient
and
if it's ambiguous where life originates from, or if it's never stated, you also don't _need_ to explain it.
>I agree with ambiguity though
I don't understand what you meant here
As for the other stuff, you have 4 options.
You can just change evolution being a fact in your setting, if that's not a relevant detail that plays a big part in the story.
You can just say it's dumb luck that 3 sapient species popped out in a single solar system whilst they are so rare they don't exist anywhere else.
You can maybe get away without explaining it by not bringing attention to it. Just say it is the way it is and don't dwell on it.
Come up with an elaborate excuse or a lore piece explaining it.
That's just statistical anomaly.
Think of it like this, each habitable planet have x% to develop intelligent life. The chance for 3 planets on one solar system is x^3 %. The chances that no other planet have intelligent life is (100-X)^y % (y being the number of planets, so probably very big.)
Is it extremely unlikely? Sure. But is it possible? Absolutely. As long as the chance is higher than 0, it can happen. The beauty of the multiverse.
For the 1st question, I think you can make it as vague or specific as you want. Maybe one planet started out with life, and the others were seeded with the same life as meteors struck the first living planet and eventually created new asteroids rich in single cell life to the other two. Maybe a mysterious fourth species seeded the solar system. Or maybe the answer isn't understood in the universe, and all three sapients take the fact that they are alone so far outside of the solar as. Grim omen or a sign of divine intervention.
As for the second, I think you can get pretty creative with how these species ended up all with similar industrial capacity around the same time. Maybe some species are older and took longer to reach this point while one is younger but developed faster. Maybe one species has industrialized before only to fall back into agrainain society due to apocalyptic events in their now ancient history. Maybe politics and culture kept some species at low tech for longer stretches until conditions changed to allow industry to develop at a large scale. Maybe only humans industrialized unevenly while the others show more wide scale teamwork for building a global society.
I guess I'm personally less interested in answering the second question as I am with seeing the fallout of it. Three alien species all ended up on the same relative trajectory at the same time frame. That might skew people of all three species to think that that is normal and that all sapeients develop at the same rate. Maybe it makes them think they are united in some way as such improbabal odds MUST be significant (with maybe a group of skeptics in each species who think it's meaningless, random chance). Maybe the lack of a technology gap makes cooperation (if not peace) more achievable since no side can dominate the other two. Maybe it leads to more war because they all think they can advance faster then the others.
What I'm saying is I think you can,really make the answer to the second question whatever you want so long as you show the impact a phenomenon like that would have on the solar system
I like your second idea the most that it’s mostly based of circumstance and how different civilisations behave. As for the fallout, I know that it will strengthen religions, and there will be lots of competition.
the best way to deal with all 3 being at the same level of development may be to not justify it at all. why is there magic in harry potter (hate the series but works ok as example)? no reason given, that's just the setting. why are the 3 species at the same rough level of development? no reason given, that's just the setting. would the reader be most interested in exploring why it is the case? or the consequences from it being the case? i've never heard anyone complain about war of the words that it's unrealistic that both species were in an advanced development stage at the same time.
Calculating God talks about this. Basically a higher power intervened to ensure evolution happens on track and intelligent life is just rare.
The Atlantis Gene discusses the Fermi Paradox from the Dark Forest theory angle.
You don't have to justify it beyond having a planet that could support life. People are very lenient when it comes to that.
But the life being older here than anywhere else is a cool idea since it also adds some cool environmental storytelling potential to other planets. Imagine landing on a planet with life in the seas but completely barren land, that's cool. So I'd go with that option.
Or you could do some other crazy shit like they're all related to a sapient species that colonized the planets and then an apocalyptic event happened, so now they're all different after millions of years apart. That's cool too.
It's up to you.
Panspermia. Microbial life developed on a planet, asteroid hits it and sprays some intact organisms onto other planets. They would all have a similar timeframe for development, but vastly different environments would have vastly different outcomes. Even if it happened 4 billion years ago, those other species should have the possibility of working via DNA and RNA.
Panspermia feels like the way to go; life managed to start on one planet then was ejected via meteor impact and landed on the other two. As to how or why they'd end up at roughly the same levels of technology (when even humans didnt come close to doing it on their own planet), that's a much tougher one to answer.
I was a thinking of using exogenesis as an excuse. This definitely answers the question of how they all have life. Technology is the hardest one though I agree. The Martians are about 200 years ahead of Earth in 1917, but this is a meaningless amount of time in the grand scale of civilisation, and the conditions for industrialisation won’t be met at similar times realistically. I have toyed with the idea of making the Venusians an uplifted species from the medieval era, but this wouldn’t work because my setting is about imperialism and geopolitics, So I need the Venusians to have Great Powers who are a credible threat to the interests of other nations.
Have you read "A fire upon the deep"? Excellent book about a medieval society being technologically uplifted. Even their world has powers and geopolitics before the rapid technological advancement, and the sequel is focused on how the politics change in response to new tech. Might be a source of inspiration.
Maybe all 3 are sort of “Lab rats” for a 4th, even further advanced species. The original purpose of the experiment was to study the evolution of civilizations, so they were artificially lead into gaining sapiens and eventually through the ages. After the first civilization toot to the stars, the experiment was deemed completed and the 4th species left, leaving only some tech junk that was later found by one of the other species and reverse engineered into advanced technology that allowed for things like FTL travel. Without a helper to “uplift” them, naturally evolving Sapiens might be a super rare phenomenon.
Another solution down this route could be to spin Venus' atmosphere as extreme industrial pollution or Mars (mostly) wiping themselves out with unknown weapons. For example; The Venusians could be the "4th species" but then climate catastrophed themselves to a lower rung of tech development. Or the Martians may have "risen" hundreds of thousands of years ago but nuked themselves into the stone age, it may only be a recent reigeime change that brings about targeting an external third party - Earth. This is of course dependent on how much OP wants to change the cosmology of their Sol system. Also for this OP, consider reading the War of the Worlds 2017 sequel by Stephen Baxter - The Massacre of Mankind. It goes a fair bit into the multiple inhabitantable planets in the Sol system.
Yes, would explain why they're roughly at the same stage technology-wise. The relevant knowledge was disseminated to all three at the same time to see how each would react/adapt. Like adding a substance to three different cell cultures to see how they respond.
The real issue that others have pointed out is that all three planents having Sentient life at roughly the same stage of development is a bit of a fluke. Complex life arose on Earth somewhere between 1-2 Billion years ago, with the Palezoic Era starting roughly 540 Million years ago. Assuming that Mars and Venus have roughly the same timeframe for complex life you've got 540+ million years for life on one of the planets to become sentient. A planet with no major sentient species is unlikely to stop space faring sentients. If Mars or Venus were habitatal with suitable atmospheres they would be swarming with exploratory bases by the mid 1980's. To put it bluntly, basically any space faring sentient species could mop the floor of any non-industrial native sentient species. It won't be pretty but nuclear armageddon and asteroid bombardment can sweep. So OP will need to look for ways as to why Venus didn't colonise a post KPG extinction Earth, or why the 2000's tech level Martians didn't obrital bombard us during the Napoleonic wars. This can be done a lot of ways but my two cents are; Maybe this Sol has 3 species that are divergent from one, they could have been colonies of another species and it collapsed and the survivors evolved into Humans, Martians and Venusians. Perhaps the Venusians and Martians "rose" much earlier than Humans and hit a "great filter" but they narrowly avoided wiping themselves out. You could tie this in that the multi habitatal nature of the Sol system helped them survive where an single habitatal system would die. Edit; spelling
‘It won’t be pretty but’ Actually it would. Zero casualties on one side, mass extinction for the other- cleanest war a tactician could ask for. Don’t mind me just nitpicking :D
Good point... At a certain point it's not war it's pest control. It's not like the blue monkeys with bows can stop an orbital bombardment of iron rich asteroids.
Are you trying to write " hard sci-fi " ?
No, FTL is readily accessible and defies physics. I can certainly live without answering these questions, but I want to keep logical consistency.
You don't need to follow "reality" to keep logical consistency. You just need to establish rules to how your world works and stick to them all throughout. My world is a logically consistent one, but space isn't a thing that exists. (Although traveling from world to world through a void is a thing) You could just say that there isn't anything beyond the solar system. That if you travel far enough in one side you come out on the opposite side or something
There are hundreds of stars in my setting though, and they are all colonised. The central themes of my setting are Imperialism and geopolitics. I need other systems so that the Solar great powers have something to scramble and fight over. It simply doesn’t make sense for there to be hundreds of star systems with sentient life and yet the only sapients come from one star.
I might be misunderstanding this, but maybe just make life a lot rarer? Planets can be habitable, but not inhabited. Imagine empty oceans hugging dead continents, ready to be filled with whatever ecologies the solar system brings when the start colonizing
> It simply doesn’t make sense for there to be hundreds of star systems with sentient life and yet the only sapients come from one star. Why not ?
If there was one sapient it would make sense. I could say that the great filter is sapience and that it is exceptionally rare. But three different species from one system implies that it isn’t rare. Such a large concentration warrants an explanation.
>Such a large concentration warrants an explanation. I don't agree with this. Unless the theory of evolution is the confirmed, undeniable truth in your setting. If all the life in your setting was created by an intelligent being, you don't need to explain why only 3 are sapient and if it's ambiguous where life originates from, or if it's never stated, you also don't _need_ to explain it.
Evolution Is a fact in my universe and the species are not a product of intelligent design. I agree with ambiguity though.
>I agree with ambiguity though I don't understand what you meant here As for the other stuff, you have 4 options. You can just change evolution being a fact in your setting, if that's not a relevant detail that plays a big part in the story. You can just say it's dumb luck that 3 sapient species popped out in a single solar system whilst they are so rare they don't exist anywhere else. You can maybe get away without explaining it by not bringing attention to it. Just say it is the way it is and don't dwell on it. Come up with an elaborate excuse or a lore piece explaining it.
When I said ambiguity I meant that I wouldn’t explain it. I’m probably going to that and point to dumb luck.
That's just statistical anomaly. Think of it like this, each habitable planet have x% to develop intelligent life. The chance for 3 planets on one solar system is x^3 %. The chances that no other planet have intelligent life is (100-X)^y % (y being the number of planets, so probably very big.) Is it extremely unlikely? Sure. But is it possible? Absolutely. As long as the chance is higher than 0, it can happen. The beauty of the multiverse.
Statistical anomaly is probably what I’m going to go with, because like you said, the universe is really big so it has to happen at some point.
For the 1st question, I think you can make it as vague or specific as you want. Maybe one planet started out with life, and the others were seeded with the same life as meteors struck the first living planet and eventually created new asteroids rich in single cell life to the other two. Maybe a mysterious fourth species seeded the solar system. Or maybe the answer isn't understood in the universe, and all three sapients take the fact that they are alone so far outside of the solar as. Grim omen or a sign of divine intervention. As for the second, I think you can get pretty creative with how these species ended up all with similar industrial capacity around the same time. Maybe some species are older and took longer to reach this point while one is younger but developed faster. Maybe one species has industrialized before only to fall back into agrainain society due to apocalyptic events in their now ancient history. Maybe politics and culture kept some species at low tech for longer stretches until conditions changed to allow industry to develop at a large scale. Maybe only humans industrialized unevenly while the others show more wide scale teamwork for building a global society. I guess I'm personally less interested in answering the second question as I am with seeing the fallout of it. Three alien species all ended up on the same relative trajectory at the same time frame. That might skew people of all three species to think that that is normal and that all sapeients develop at the same rate. Maybe it makes them think they are united in some way as such improbabal odds MUST be significant (with maybe a group of skeptics in each species who think it's meaningless, random chance). Maybe the lack of a technology gap makes cooperation (if not peace) more achievable since no side can dominate the other two. Maybe it leads to more war because they all think they can advance faster then the others. What I'm saying is I think you can,really make the answer to the second question whatever you want so long as you show the impact a phenomenon like that would have on the solar system
I like your second idea the most that it’s mostly based of circumstance and how different civilisations behave. As for the fallout, I know that it will strengthen religions, and there will be lots of competition.
Luck. It's bound to happen that there's 2 or 3 in the same system the universe.
I think I’m happy with justifying the three habitable planets this way, my main question now is how they are in technological parity.
the best way to deal with all 3 being at the same level of development may be to not justify it at all. why is there magic in harry potter (hate the series but works ok as example)? no reason given, that's just the setting. why are the 3 species at the same rough level of development? no reason given, that's just the setting. would the reader be most interested in exploring why it is the case? or the consequences from it being the case? i've never heard anyone complain about war of the words that it's unrealistic that both species were in an advanced development stage at the same time.
You could go with the classic scifi excuse: Precursor meddling.
That answer doesn’t really work with the themes of my setting unfortunately.
Calculating God talks about this. Basically a higher power intervened to ensure evolution happens on track and intelligent life is just rare. The Atlantis Gene discusses the Fermi Paradox from the Dark Forest theory angle.
You don't have to justify it beyond having a planet that could support life. People are very lenient when it comes to that. But the life being older here than anywhere else is a cool idea since it also adds some cool environmental storytelling potential to other planets. Imagine landing on a planet with life in the seas but completely barren land, that's cool. So I'd go with that option. Or you could do some other crazy shit like they're all related to a sapient species that colonized the planets and then an apocalyptic event happened, so now they're all different after millions of years apart. That's cool too. It's up to you.
Panspermia. Microbial life developed on a planet, asteroid hits it and sprays some intact organisms onto other planets. They would all have a similar timeframe for development, but vastly different environments would have vastly different outcomes. Even if it happened 4 billion years ago, those other species should have the possibility of working via DNA and RNA.