It's generally agreed in the subject of Planetary Protection that we shouldn't colonize Europa. The problem is that it is such an interesting place for life, and there is a reasonable chance it has native lifeforms. And with a surface of ice, global subsurface ocean, and water plumes, any landing of humans there obviously has a significant risk of contaminating it with Earth life.
Even if it doesn't have life, we would want to know what it is like without introducing Earth life first. Does it have complex chemicals? Does it have DNA? Or XNA, or TNA not yet in the form of life? Does it have nanobe sized proto lifeforms? Or what happens to a global ocean rich in oxygen like Europa left to itself for billions of years? We will certainly want to know that before even considering sending humans there. And some scientists think we have a responsibility to keep Europa clear of Earth life not just for ourselves, for future studies in the next few decades or centuries, but for all future time. So even once we have studied it, and have a rough idea what it is like and if it has life, there would be many who would say we shouldn't colonize it.
Mars is a bit different, there some people think that the surface is so sterile that human exploration wouldn't make a significant difference for planetary protection. While others say they would. This would have to be resolved before we send humans to the surface of Mars.
But in the case of Europa, everyone is in agreement, in the planetary protection workshops discussing it. To the extent that they also take great care to make sure that none of the unmanned spacecraft sent to the Jupiter system have any chance of crashing into Europa. At the end of the spacecraft lifetime you have to show that it can't do that.
In any case the surface levels of radiation for Europa are so high, because it orbits right within the Jupiter version of the Van Allen belts which are also stronger than for Earth. The radiation would kill humans within hours. So - not an ideal place for humans. Yes would be protected in the ocean, but we wouldn't want humans there anyway.
Any humans in the Jupiter system would be further out, perhaps Callisto. Which has an ancient surface, no evidence of activity. Less radiation anyway, it's just outside the main radiation belt for Jupiter. And it may well have a subsurface ocean also, but it does not communicate with the surface as far as we know.
Or else, just orbiting Jupiter in an orbital settlement.
At any rate Jupiter is tough of access. Hohlman transfer getting on for two years, see Voyager - Jupiter
Before we can consider sending humans there, we need them to be able to survive long term, without resupply, in closed system habitats for a couple of years in space at least, preferably a lot longer for a safety margin. We are nowhere near that capability yet. Will soon probably have the capability to send the launch mass to Jupiter, but to actually survive the journey there is another thing altogether.
So not a thing we need to decide soon, how humans can survive in Jupiter orbit. Though there are people who are really keen on sending humans to the Jupiter system.
There is even, apparently, a group of people who want to do a one way manned trip to Europa.
I think, you are right, that once you get to Europa and if you can bury yourself beneath the ice quickly enough, within minutes of arrival on the surface, you'd be better able to survive there than on Mars. Because the advantages of an oxygen rich ocean, at temperatures similar to an Earth sea would be hard to beat, comparable probably to living permanently in an Earth sea or an Antarctic subsurface ice lake perhaps. I mean you'd never colonize such a place on the Earth but as you say - it would be a great analogue of Europa.
Move over, Mars: Manned Europa mission considered - CNET
But no way would these proposals pass planetary protection as mandated in the Outer Space Treaty signed by all space faring nations, and aspiring ones (even N. Korea), and just about all other nation states also. As with Mars missions, then often the enthusiasts give little consideration to the subject.
But before such a mission could be launched, those concerned would need to satisfy the rest of us that they are taking adequate planetary protection precautions, and would not contaminate Mars, or in this case Europa with Earth life. And this is a responsibility of the governments of both the state they are citizens of, and the state that provides the launching platform and rocket components, all those involved. And doesn't matter where they launch from, the responsibility extends to their activities once they are in space also.
E.g. all Elon Musk's activities in space are the responsibility of the US government, to make sure he keeps to planetary protection policies. In case of Mars One launching using US rockets, it's responsibility of both Netherlands and the US, and also the governments of all the countries that have citizens taking part in the mission to make sure that it complies with the planetary protection policies. No matter where they launch from. They have none of them suggested that they intend to breach these international laws anyway, I hasten to add.
In the case of Mars there is the idea of an "exploration phase" which however keeps being extended, the idea that at some point we may know enough about the planet so that we don't need to keep it pristine any more for scientific study. With some scientists saying it should have no end date.
So space colonization enthusiasts who want to send colonists to Mars may think that at some point we will know enough about Mars to have finished this "exploration phase". Or they may think that we will find out that the surface of Mars is so hostile that no Earth life can survive there unprotected (that of course would also make it very hostile for humans also).
In the case of Europa nobody in the planetary protection discussions has yet suggested it should have an "exploration phase" at all. So, despite these ideas of enthusiasts, I don't see that happening any time soon.
Also as well as that - in Antarctica also they take great care not to contaminate the sub surface lakes with Earth life, because they have been isolated from the surface for so long, and they want to know what happens to life in such conditions, with no communication with surface life. Introducing surface life would confuse their findings.
The Russians drilled to within a few meters of Lake Vostock and then stopped for many years as they developed the technology to go for the last few meters into the lake itself without contaminating it. And the US similarly sent their first exploration to a similar lake again taking great precautions.
So just like with Europa, they would not permit humans to colonize or even explore these places yet, until they have a chance to study them, and quite possibly never.
If you want to attempt colonization of space - well I'd recommend the Moon, there are no planetary protection requirements there at present as it is thought to be impossible for Earth life to survive there. And it is also a major challenge to keep humans alive even within 2 days journey from Earth, surely best to crack that one first. Or more space station type colonies.
Or, my own favourite for human space exploration, a space station in the L2 position, far side of the Moon, explore the surface telerobotically - lots of science value as it is hard to study the far side of the Moon - and a challenging place to send humans, but not too challenging, easier to get back to Earth even than from the lunar surface, it's a logical next step from LEO as an interesting place to send humans that is just difficult enough to be a major challenge, but not so challenging as to be a huge safety issue for humans.
The logistics even for that likely to be a major challenge - though at the worse, with improving launch capabilities we could just launch supplies there every few months as with the ISS. But to be a good precursor for interplanetary exploration, should be designed for resupply only every couple of years or so, if that is at all possible.
If that can't be done, if we don't have the technology for a multiple year space station at L2, and we certainly can't do that at a reasonable cost with present day technology - I'd say that no way are we really ready for large scale interplanetary human exploration or settlement, never mind colonization.
See also : Robert Walker's answer to Has NASA purposefully sent any life forms to other planets?
Even if it doesn't have life, we would want to know what it is like without introducing Earth life first. Does it have complex chemicals? Does it have DNA? Or XNA, or TNA not yet in the form of life? Does it have nanobe sized proto lifeforms? Or what happens to a global ocean rich in oxygen like Europa left to itself for billions of years? We will certainly want to know that before even considering sending humans there. And some scientists think we have a responsibility to keep Europa clear of Earth life not just for ourselves, for future studies in the next few decades or centuries, but for all future time. So even once we have studied it, and have a rough idea what it is like and if it has life, there would be many who would say we shouldn't colonize it.
Mars is a bit different, there some people think that the surface is so sterile that human exploration wouldn't make a significant difference for planetary protection. While others say they would. This would have to be resolved before we send humans to the surface of Mars.
But in the case of Europa, everyone is in agreement, in the planetary protection workshops discussing it. To the extent that they also take great care to make sure that none of the unmanned spacecraft sent to the Jupiter system have any chance of crashing into Europa. At the end of the spacecraft lifetime you have to show that it can't do that.
In any case the surface levels of radiation for Europa are so high, because it orbits right within the Jupiter version of the Van Allen belts which are also stronger than for Earth. The radiation would kill humans within hours. So - not an ideal place for humans. Yes would be protected in the ocean, but we wouldn't want humans there anyway.
Any humans in the Jupiter system would be further out, perhaps Callisto. Which has an ancient surface, no evidence of activity. Less radiation anyway, it's just outside the main radiation belt for Jupiter. And it may well have a subsurface ocean also, but it does not communicate with the surface as far as we know.
Or else, just orbiting Jupiter in an orbital settlement.
At any rate Jupiter is tough of access. Hohlman transfer getting on for two years, see Voyager - Jupiter
Before we can consider sending humans there, we need them to be able to survive long term, without resupply, in closed system habitats for a couple of years in space at least, preferably a lot longer for a safety margin. We are nowhere near that capability yet. Will soon probably have the capability to send the launch mass to Jupiter, but to actually survive the journey there is another thing altogether.
So not a thing we need to decide soon, how humans can survive in Jupiter orbit. Though there are people who are really keen on sending humans to the Jupiter system.
There is even, apparently, a group of people who want to do a one way manned trip to Europa.
I think, you are right, that once you get to Europa and if you can bury yourself beneath the ice quickly enough, within minutes of arrival on the surface, you'd be better able to survive there than on Mars. Because the advantages of an oxygen rich ocean, at temperatures similar to an Earth sea would be hard to beat, comparable probably to living permanently in an Earth sea or an Antarctic subsurface ice lake perhaps. I mean you'd never colonize such a place on the Earth but as you say - it would be a great analogue of Europa.
Move over, Mars: Manned Europa mission considered - CNET
But no way would these proposals pass planetary protection as mandated in the Outer Space Treaty signed by all space faring nations, and aspiring ones (even N. Korea), and just about all other nation states also. As with Mars missions, then often the enthusiasts give little consideration to the subject.
But before such a mission could be launched, those concerned would need to satisfy the rest of us that they are taking adequate planetary protection precautions, and would not contaminate Mars, or in this case Europa with Earth life. And this is a responsibility of the governments of both the state they are citizens of, and the state that provides the launching platform and rocket components, all those involved. And doesn't matter where they launch from, the responsibility extends to their activities once they are in space also.
E.g. all Elon Musk's activities in space are the responsibility of the US government, to make sure he keeps to planetary protection policies. In case of Mars One launching using US rockets, it's responsibility of both Netherlands and the US, and also the governments of all the countries that have citizens taking part in the mission to make sure that it complies with the planetary protection policies. No matter where they launch from. They have none of them suggested that they intend to breach these international laws anyway, I hasten to add.
In the case of Mars there is the idea of an "exploration phase" which however keeps being extended, the idea that at some point we may know enough about the planet so that we don't need to keep it pristine any more for scientific study. With some scientists saying it should have no end date.
So space colonization enthusiasts who want to send colonists to Mars may think that at some point we will know enough about Mars to have finished this "exploration phase". Or they may think that we will find out that the surface of Mars is so hostile that no Earth life can survive there unprotected (that of course would also make it very hostile for humans also).
In the case of Europa nobody in the planetary protection discussions has yet suggested it should have an "exploration phase" at all. So, despite these ideas of enthusiasts, I don't see that happening any time soon.
Also as well as that - in Antarctica also they take great care not to contaminate the sub surface lakes with Earth life, because they have been isolated from the surface for so long, and they want to know what happens to life in such conditions, with no communication with surface life. Introducing surface life would confuse their findings.
The Russians drilled to within a few meters of Lake Vostock and then stopped for many years as they developed the technology to go for the last few meters into the lake itself without contaminating it. And the US similarly sent their first exploration to a similar lake again taking great precautions.
So just like with Europa, they would not permit humans to colonize or even explore these places yet, until they have a chance to study them, and quite possibly never.
If you want to attempt colonization of space - well I'd recommend the Moon, there are no planetary protection requirements there at present as it is thought to be impossible for Earth life to survive there. And it is also a major challenge to keep humans alive even within 2 days journey from Earth, surely best to crack that one first. Or more space station type colonies.
Or, my own favourite for human space exploration, a space station in the L2 position, far side of the Moon, explore the surface telerobotically - lots of science value as it is hard to study the far side of the Moon - and a challenging place to send humans, but not too challenging, easier to get back to Earth even than from the lunar surface, it's a logical next step from LEO as an interesting place to send humans that is just difficult enough to be a major challenge, but not so challenging as to be a huge safety issue for humans.
The logistics even for that likely to be a major challenge - though at the worse, with improving launch capabilities we could just launch supplies there every few months as with the ISS. But to be a good precursor for interplanetary exploration, should be designed for resupply only every couple of years or so, if that is at all possible.
If that can't be done, if we don't have the technology for a multiple year space station at L2, and we certainly can't do that at a reasonable cost with present day technology - I'd say that no way are we really ready for large scale interplanetary human exploration or settlement, never mind colonization.
See also : Robert Walker's answer to Has NASA purposefully sent any life forms to other planets?
About the Author
Robert Walker
Writer of articles on Mars and Space issues - Software Developer of Tune Smithy, Bounce Metronome etc.Studied at Wolfson College, Oxford
Lives in Isle of Mull
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