It is the toughest step surely for it to find a habitat. But - the endospores are also amazingly long lived ...
But the human ones are less likely to have such amazing lives of dormancy. We should certainly be very careful about backward contamination; somewhat less so for forward contamination. Even so, we should study Mars from orbit for a good while before attempting to land.
Ah - but how likely is your "less likely"? Out of 1000 species in 19 phyla on the human skin.
Also many Archaea some so hard to study we don't even know how many phyla there are. Though not endospore forming, some extremophile may be able to survive without metabolising for a long time on the surface of Mars protected from UV. If all you have of some of the extremophiles on the spaceship are some RNA sequences you were able to duplicate, you can't say anything really about what they might do on Mars.
"less likely" just isn't good enough. You need to prove it can't happen.
I agree we need to care about backward contamination. But the risks are so high both ways, with backward contamination you risk at worst the human race or more, so that's of course a higher risk in a sense, but the other way you risk messing up a whole planet and losing much of incalculable value.
I don't really myself want to call that a "lesser risk" as if it doesn't matter so much.
As for the grain of dust, you haven't convinced me that it can't happen, so many endospores, so many grains, gigantic on the scale of an endospore, not only does it seem possible, just seems a matter of time before it actually happens.
There are so many other ways it could happen too, it's like the many headed hydra. If you finally manage to show that one vector can't happen another will just pop up in its place. So - in the air, on a pebble, lands in a drop of water, falls into a shadow, is trodden into the ground by an astronaut or the wheel of a rover, gets stuck to the wheel of a rover, gets stuck to a fleck of material from the parachute and blown away in the wind, gets buried deeper into the ground during an excavation, down to level of permanent briny water possibly.... That's just a selection there are probably many other ways it could happen during a human mission to Mars.
Just one oversight, one vector missed, and one endospore that gets through all the problems unscathed all the way to a habitat where it is able to survive, and that's the end of your planetary protection policy. Like with one of the early Moon missions when they opened the space capsule door by mistake when it was in the ocean, so any micro-organisms inside would have immediately found a nice warm vast wet habitat to reproduce in.
It's really not up to me to prove it can happen, not with something with as long term consequences as this. Just to suggest ways that it might happen, so long as it is at least semi-plausible it can happen, it's up to those who still propose that humans do visit Mars to prove rigorously that it can't happen. A hunch even a well informed one is just not good enough as they can be like the anaerobic halophiles that that expert said couldn't exist when he recommended dropping planetary protection protocols for Mars before Sagan's paper.
Also no-one has answered the issues with a human occupied spacecraft crashing during the landing on Mars. Until that can be solved, I think Mars has to be a no-go area for humans, even if you do somehow solve the issues to do with what happens when you get there.
Why run those risks at all.
Seems to be lots to like about telepresence, and really nothing much to prefer about humans on the surface except that natural feeling that humans like to be there, and wanting to see other humans walking about on the surface of Mars.
I feel that natural feeling too, imagination fired by the idea of humans walking on Mars. It would be great to colonise Mars, would be so interesting and exciting, I'd be following every step like with the Moon landings when I was young.
But you and I won't feel so good about it any more if a decade later we discover that the climate of Mars has started to change, and that the surface is covered in organisms of Earth origin, that some of the organisms there are become pathogens, and that humans can no longer hope to safely live on the surface of Mars.
Then perhaps you find out that there was some amazing life form living on Mars in some particular secluded spot, and organic deposits 4.5 billion years old - and now they are all just a slowly decomposing mass of Earth bacteria plus a few intriguing fossils of the hard parts of the organisms that no-one is quite sure how to intepret.
Someone should make all this into a blockbuster movie, it might create quite an impact. Or a good sci fi story at least. I wish I could write one, but though okay at expressing myself in writing, I've tried and just don't have the knack to write a good story like that, not yet anyway.
It might not happen. The worst outcomes there might even be low probability. But right now we simply don't have any way to be sure, and that's not good enough in my book.
Sorry to keep saying the same thing, seems a bit that I am. I should probably stop soon, especially as I feel I'm beginning to repeat myself
This is the sort of conversation where sometimes its good to take a break from it and try again later when everyone has had a chance to reflect on it more.
The main thing in my book is there should be extreme caution for the first human mission to Mars, also for the first mars sample return.
If the first mission to Mars with humans is done from orbit and with telepresence, and the first MSR is done to high orbit or the Moon, that will satisfy the likes of me for the time being.
Then we will learn so much about Mars from that.
Hopefully also there will be more research into the contamination issues. Maybe also ways will be found to study the Archaea. Also with large quantities of Mars samples returned, e.g. to the Moon, similar quantities to the return of the Moon rocks to Earth, can actually study, with real Mars samples and with simulated Mars atmosphere, in detail, what is likely to happen to it when Earth life is introduced to it.
So in various ways we can study Mars, and study what the contamination issues really are in more detail and maybe we can have this conversation again when we all know more about it.
I can imagine the live feed from Mars explored by telepresence would be pretty interesting too. Agree that a cute anthropomorphic robot or dog with big camera lens eyes operated by telepresence would probably increase the audience ratings
. But - if they just move more quickly than the current rovers, and can travel long distances like hundreds of Km even, that would make it more interesting too, if when you see an interesting rock on the horizon and drive there the same day instead of weeks later.
Robert the Inventor: BigDog Rox! Thanks for sharing. When the guy kicked him, he was able to maintain his footing! Same on the ice!
True, as you point out in a later post, "Human
location locomotion is quite efficient". However, it is the robot which mimics human locomotion which is not.
Yes it does doesn't it, I was impressed by that too.
With the human locomotion, - the ones like Asimo obviously could be more efficient than they are, but probably limited in how much better then can get yes, if just based on simple engineering.
My thought there is based on that chap who is imitating the human skeleton, and including even the way the muscles are able to absorb energy and re-release it just like ours do. A robot that incorporates that could be much more efficient at walking, if it incorporates those same tricks our body uses to reduce the amount of energy needed, perhaps it could be nearly as efficient as we are.
Sorry I didn't explain that well but hopefully it is clear now.
I trot out again, heh heh, my idea of horses on the Moon, and Mars by extension. Yes, they'd need spacesuits, already demonstrated for humans, readily conceived scalable for horses. All of the software, thanks to evolution, is included in the horse itself. Several paces, low energy consumption, self balancing, intelligent and easily trained, strong. What's not to like? Possibly even cheaper to keep in operating than a robot of similar capability. Not only that, why not dogs? They could carry samples and tools, and be quite useful.
For mars at a later stage in terraforming, if the decision is made that it's okay to go ahead, I like the idea of using mammoths, which we might well be able to clone by then.
They have special adaptations of the blood to really cold conditionshttp://news.discovery.com/animals/woolly-mammoth-blood-bacteria-cold.html
As for suits for animals, or better suits for humans, this one using "lines of non extension" would be much easier to use than modern spacesuits which are basically "miniature spaceships"http://mvl.mit.edu/EVA/biosuit/
Just that I wouldn't use it for Mars astronauts quite yet, obviously.
I've got the same adventurous and imaginative spirit when it comes to space as I expect the rest of you have, read the sci fi stories and imagination fired up by them. Go back say twenty years and I thought there were no problems at all with colonising Mars, hadn't heard of these issues and if I was posting on a board like this then I'd say just what you are saying. I'd be all for an immediate manned mission to Mars.
But nowadays, after what I've found out about the issues, there is no way I'd advocate colonising Mars at present, not until all these concerns and issues are laid to rest.
So anyway for a quick summary of what the issue is.
The one about a spacecraft rupturing on landing I think is the most convincing, as it's the one that you can never argue out of.
You can argue this way and that about the endospores, and it really needs more reseach to understand it clearly and we may never get a concensus opinion about what exactly is likely to happen.
But it is easy see that there is nothing at all you can do to protect the planet in the event of a crash landing of a human occupied spaceship.
And - of course backward contamination is the highest risk of all if it could mean extinction of the human race. But forward contamination is risking so much as well in my book.
BTW did you know as a result of this thread, literalitudinity has become briefly a Googlewhackblatt and coincidentally also has the same number of letters as Googlewhackblatt
Won't last for long as there are three posts here now using the word.