What exactly do we know about the Solar System?

[TheDungen]

Its possible it was done while earth and the solar system was cut of from the galaxy by warpstorms

[Endobai]

Actually Venus is theorised to be capable of being terraformed with our current level of technology, although we wouldn't see any benefits to doing so for several hundred years. If you place a solar mirror (think big reflective parachute) about 15 kilometers in diameter in orbit over Venus you would reflect enough heat to lower to the temperature of the atmosphere so that the heavier elements wouldn't have the energy to remain floating about and they'd settle on the surface. With the density of the atmosphere reduced, it would retain less heat and further elements would settle, which would reduce heat retention further, and so on and so on. A reverse greenhouse effect. Without the heavy atmosphere the crushing pressure would also be alleviated.

Also you could colonise Venus without doing any of that. Venus sports the closest atmosphere to Earth anywhere in the solar system - 50km up in the Venusian sky. It has virtually the same temperature and pressure as Earth, and oxygen acts as a lifting gas on Venus so you could fill a zepplin with the stuff and it would float. With you inside it. You could step out into the bracing Venusian atmosphere with nothing but an oxygen mask if you really wanted, although the dilute sulphuric acid might sting a little.

Of course this is the fantastical grimdark 40k we're talking about. The Imperium would probably colonise Venus by exterminatusing it so hard it would make Venus so bad that reality would have a buffer overflow and the planet would wrap around to become livable.

Very interesting, thank you!

[Retrospectus]

I would love to see a BL novel about an invasion of the solar system. maybe by a HUGE waaagh, a massive black crusade or a new hive fleet (anything less wouldn't stand a chance)

[The bearded one]

I wonder how much use the solar defense systems actually get. That system has so many guns bolted on, there's no chance in hell of pulling off small raids.

[Endobai]

I wonder how much use the solar defense systems actually get. That system has so many guns bolted on, there's no chance in hell of pulling off small raids.

The Necrons did something to test the defences, unless it was retconned subsequently.

[The bearded one]

The Necrons did something to test the defences, unless it was retconned subsequently.

I don't think that was even taken out. It just wasn't mentioned in the new necron codex, but fluff can come from different sources at the same time after all, and the fluff of those 5 ships still fits if you twist the idea that they were looking for the dragon C'tan, into that they were looking for a shard of the dragon, in order to capture it, rather than set it free.

In any case, those necron ships were actually vaporised shortly after landing.

[Lord Damocles]

Even ignoring the fact that the Necron Martian raid hasn't been mentioned for a while, it still gets a mention in Battlefleet Gothic Armada, which is still in print (pg.77).


The five Shrouds made a mockery of the system's/Mars' defences. They got into the Sol System and past the Titan monitoring station undetected. They made it past several flotillas of system ships, through at least one minefield, passing thousands of mines without activating any of them. Then they got through the Deimos orbital weapon battery chain unharmed. They lost a ship to the Phobos defence line, but it was destroyed by one of the other Shrouds targeting it, not by the lance batteries.
They made it to the surface of Mars with at least one ship landing, and were able to avoid Navy attack craft for several hours while destroying mine workings in the Noctis Labyrinthus.
All four ships were eventually destroyed, but their hulks weren't recovered.

[El_Machinae]

I wonder how much use the solar defense systems actually get. That system has so many guns bolted on, there's no chance in hell of pulling off small raids.

I'd imagine that there's a LOT of small scale stuff, but on the side of 'organised crime'. Nothing military. But the Sol system is packed with people, and a decent proportion of them are desperate and willing to take risks. So, other than fraud amongst the crew, I'd imagine the big ships deal with very little. But there's probably a host of people seeking to engage in rapid, subtle piracy acts.

[The Ked]

Actually Venus is theorised to be capable of being terraformed with our current level of technology, although we wouldn't see any benefits to doing so for several hundred years. If you place a solar mirror (think big reflective parachute) about 15 kilometers in diameter in orbit over Venus you would reflect enough heat to lower to the temperature of the atmosphere so that the heavier elements wouldn't have the energy to remain floating about and they'd settle on the surface. With the density of the atmosphere reduced, it would retain less heat and further elements would settle, which would reduce heat retention further, and so on and so on. A reverse greenhouse effect. Without the heavy atmosphere the crushing pressure would also be alleviated.

Also you could colonise Venus without doing any of that. Venus sports the closest atmosphere to Earth anywhere in the solar system - 50km up in the Venusian sky. It has virtually the same temperature and pressure as Earth, and oxygen acts as a lifting gas on Venus so you could fill a zepplin with the stuff and it would float. With you inside it. You could step out into the bracing Venusian atmosphere with nothing but an oxygen mask if you really wanted, although the dilute sulphuric acid might sting a little.

Of course this is the fantastical grimdark 40k we're talking about. The Imperium would probably colonise Venus by exterminatusing it so hard it would make Venus so bad that reality would have a buffer overflow and the planet would wrap around to become livable.

I thought I'd heard somewhere that Venus' atmosphere on the surface is some crazy amount heavier than it is on the Earth's surface, hence all the probes/landers we send there being crushed moments after entering. Not to mention its the most volcanic place in the system.

Other interesting facts - one of Saturn's moons have volcanoes that erupt ice instead of lava. Now imagine a Grey Knight frollicking amongst it.

[Connor MacLeod]

I wonder how much use the solar defense systems actually get. That system has so many guns bolted on, there's no chance in hell of pulling off small raids.

They probably get constant use. There's always going to be traffic moving in and out of the Sol system, and security being what it is, they have to investigate everything that comes in and out. I'd imagine at least some ships get destroyed periodically, intentionally or accidentally (some chaos cult or perceived cult tries to infiltrate Terra.) And there's the necron example people already mentioned.

We also know that parts of Battlefleet Solar were dispatched to help fight against the 13th Black Crusade (as per the Andy Hoare warbook of the same name BL put out.) so they do get deployed out system.

[Endobai]

We also know that parts of Battlefleet Solar were dispatched to help fight against the 13th Black Crusade (as per the Andy Hoare warbook of the same name BL put out.) so they do get deployed out system.

It is Segmentum Solar's battlefleet, not a fleet of the Solar system.

I'd believe that ships are sent elsewhere on rotating schedule to train cews, that warships are sent to the Solar system as a reward for long service or as an ultimate reward for great commanders (for example for a couple of years), but the fleet itself is kept largerly intact.

Not to mention that there must be a fleet of system ships not capable of warp travell + elements of Battlefleet Solar, Martian fleet(-s) of Adeptus Mechnicus, forces of Jupiter forge world, Grey Knights' ships which aren't sent elsewhere, warships of several Astartes chapters (most notably Imperial Fists), Inquisitorian Black Ships with escorts and lots of lots of other hoovering killing metal monsters.

[bittick]

In real life we'd probably never terraform Venus. For less effort you could make Earth into an utter paradise. Building 50-mile tall towers stretching into the sky with gardens and pools would be easier. And as soon as you get FTL travel you aren't going to want to mess with it. Just easier to keep looking for a planet that is less trouble. So you'd probably need an Earth that you can't redevelop (probably political issues, like you don't control the whole planet, or a big war going on), and no FTL. Then terraforming Venus might make sense. Of course, you only need those conditions to exisst for a few hundred years out of 40,000.

[Connor MacLeod]

It is Segmentum Solar's battlefleet, not a fleet of the Solar system.

Actually Battlefleet solar would be the battlefleet of the Solar sector, where Terra is (Eg Battlefleet Gothic of the Gothic Sector, Battlefleet Calixis of Calixis sector, Battlefleet armageddon, Scarus, etc. and so on.)

Besides, the book actually specified they came from the Sol system anyhow

Battlefleet Solar, the home fleet of Blessed Sol has arrived. Early. Impossibly Early.

One can read that however they want, but given that the Segmentum Solar fleet base is Mars, Sol system likely has a ton of warships and crews on hand to dispatch wherever they are needed, and a detachment from the HQ got sent to help the Cadians out.)

I'd believe that ships are sent elsewhere on rotating schedule to train cews, that warships are sent to the Solar system as a reward for long service or as an ultimate reward for great commanders (for example for a couple of years), but the fleet itself is kept largerly intact.

Not to mention that there must be a fleet of system ships not capable of warp travell + elements of Battlefleet Solar, Martian fleet(-s) of Adeptus Mechnicus, forces of Jupiter forge world, Grey Knights' ships which aren't sent elsewhere, warships of several Astartes chapters (most notably Imperial Fists), Inquisitorian Black Ships with escorts and lots of lots of other hoovering killing metal monsters

Makes sense.

[TheSaylesMan]

In real life we'd probably never terraform Venus. For less effort you could make Earth into an utter paradise. Building 50-mile tall towers stretching into the sky with gardens and pools would be easier. And as soon as you get FTL travel you aren't going to want to mess with it. Just easier to keep looking for a planet that is less trouble. So you'd probably need an Earth that you can't redevelop (probably political issues, like you don't control the whole planet, or a big war going on), and no FTL. Then terraforming Venus might make sense. Of course, you only need those conditions to exisst for a few hundred years out of 40,000.

Er, well, Terra does happen to have 50-mile tall towers and copious amounts of gold plating. The Imperium would be capable of doing it as a vanity project. Not to mention the fact that an entire additional world to exploit for resources and land for people to have families and make more people to throw into the Imperial War machine within the nigh-impenetrable system defenses of the Solar System would be incredibly useful for a galaxy at war. Also, the entire thing could have been done by Pre-Imperial civilizations and there was that whole Long Night thing in which FTL was pretty much impossible. Seems like it'd be very possible in 40k.

In real life, sure, the entire thing seems pretty implausible within our lifetimes.

[Connor MacLeod]

They wouldn't even neccesarily need to terraform venus. The Imperium is more than capable of colonizing uninhabitable worlds or even hostile enviroments (Eg Hive Worlds) it just might require a more unusual approach.

And failing that they just colonize moons or create orbital installations. They did that with Jupiter as I recall.

If the Solar system in 40K is as heavily developed as some systems (Cadia, Armageddon, the Boros Gate from "Dark Creed", etc.) there could be an insane amount of human population native to that system alone, nevermind all the transients (or people who visit and never leave.)

When you factor in Mars still probably has a fair bit of the industrial capability it exhibited during the Great Crusade (building hundreds of thousands of ships in 'A Thousand Sons') the potential fo rthe Solar system is pretty scary.

[kilkrazy]

nah they do the evolution thing and venus and mercury have been sucked into the sun by then.
i dont think they would do things much different from these days. expand oceans to galaxies and theres your answer,
tho back in pre hh days, no black ships, no inquisitors, no gks, hmm interesting. everything would have been sent outward on the expansion of man

[The bearded one]

nah they do the evolution thing and venus and mercury have been sucked into the sun by then.

Wait, what? Are you talking about the sun going supernova at the end of its life (that's several billion years away)? That'd destroy a significant chunk of the solar system, including Terra.

[khirsath]

Sol won't go supernova, it's too small. In about a 5 billion years it will expand as a red giant., which will envelope both Mercury and Venus (and possibly Terra). About a billion years from now the habital zone will have migrated outwards that Terra(Earth) will be uninhabitable with M3k technology. By M30k-40k Sol won't have changed to much to effect the planets.

More on topic: The Sol system is a bit of a barren place by M40k when you consider raw materials. I would think that most of the minor planetoids (asteroids, comets, etc) would have been cannibalized by M40k.
Pre-Crusade a huge amount of material would have been used to Terraform Mars (and most likely Venus). I'd also think that Terra/Luna would consume material at a high rate during parts of its history. My impression that the planet has gone through cycles of growth and destruction. Its possible that Terra itself has been Terraformed to 'heal' it from ancient catastrophes. In addition STL vessels will eat up a lot of the systems resources.
The early crusade would have finished off the rest of the small bodies in the sol system. Building a hive world takes a lot of material, and Mars being the largest Forge World probably used more material. Also each capital ship, starfort, fleet base, etc. are enormous in 40k. Each one is the size of a raw unprocessed asteroid. It would take several asteroids worth to get the material to make a capital ship.

I do recall Pluto being a listening station or something, but cannot recall the source (Probably 3ed or earlier). I'd imagine several Kuiper belt objects are waystations/fleet bases.

I'd imagine everything left in the Sol system would be colonized and crawling with humans. Every moon that's not been delegated to a unique role is likely covered with people. Mercury would likely be a hive world status(albeit a small one). I don't see the Imperium wasting real estate. The scale of Terra is mind boggling, the rest of the system should be as well. After all Sol is supported by a million worlds it should be at a near incomprehensible scale of settlement.

[The bearded one]

Sol won't go supernova, it's too small. In about a 5 billion years it will expand as a red giant., which will envelope both Mercury and Venus (and possibly Terra). About a billion years from now the habital zone will have migrated outwards that Terra(Earth) will be uninhabitable with M3k technology. By M30k-40k Sol won't have changed to much to effect the planets.

Woops, you're right, I used the wrong star-fate, the sun will go red giant The difference within 30-40k years ought to be minimal though.

[ManOfRust]

Politically the Solar System is probably a nightmare, so many incredibly powerful organisations, so much stratification of society. The basic shmoes have probably been trapped in the same cycle of labour, deceits and recycling for 4,000 years. Might even be that way all the way to the top, duty that can never end choking everything.

Half the Imperium would probably give their lives to be as physically close to the Emperor himself but if you're a box-mover on Io you probably don't see any further than the next rest period. Were there some role-playing articles in the dark, rogue trader days for playing on Holy Terra? Seemed as lawless as anywhere else in the empire.

As for solar resources it depends on how picky you are. If you just want dense ferrous metals there are vast volumes to be found in the asteroids between Mars and Jupiter. That is assuming you don't just siphon off hydrogen from the gas giants and utilise Mad Science to fission it into the heavier elements you need. If humanity were trapped in the Sol System for 10 millennia we would probably have tried crazier things.