They care about both. But have obligations under international law as well for the search for life. And I think it is clear that if there is any conflict between the two, that the search for life has the priority, at present anyway.
They are pursuing both at once at present, though all the missions to Mars so far have had the search for life as their top priority.
US is a signatory of the Outer Space Treaty. As such it has committed itself to
There harmful contamination has been taken to include contamination that interferes with the scientific activities of other parties to the treaty.
For more on this, see Planetary protection
They would in any case be shooting themselves in the foot if they introduce life to Mars. Because the most interesting thing about Mars is to find out if there was past life there, and if there still is life there.
With Curiosity's successor they will be sending the first ever experiment sent to Mars which arguably has colonization as the main motivation for including it - the Moxie instrument to generate oxygen on Mars - it has no value at all for the search for life, and it just adds extra mass for the rover to carry around with it, and it doesn't even make any use of the oxygen which will be discarded into the atmosphere after it is generated.
I think that is a good example of them trying to follow both goals at once.
Many people say that we need to send humans into space as a backup plan for Earth, famously of course Elon Musk. But this is not NASA's stated objective at all.
There is no significant risk of us going extinct on the Earth in the next few hundred million years, except by our own actions. The dinosaurs didn't have telescopes and had no way to deflect asteroids. If they did, they could have spotted something that large from the other side of the solar system (it was as large as Mars's outer moon Deimos). It would surely have done many flybys of Earth also because the Earth is a tiny target, before it hit.
And for that matter, they had no way to escape from its effects. Couldn't dig underground or build fireproof shelters, or stockpile food, or use submarines or boats or planes to escape. And there's only one in a million chance of such an impact in the next century. And other suggested disasters are first, even less likely, and also, would be similarly survived by a large fraction of our population with technology.
With our technology we can also not just detect asteroids but also divert them. There are many more of the smaller asteroids than larger ones. So it's almost certain that the first asteroids predicted to hit Earth will be of the scale of a hundred meters max, rather than the huge kilometer sized or larger ones of the asteroid scare stories you read. And the larger ones, we'd almost certainly spot thousands of years in advance, with many close flybys of Earth first. Even if there is just one close flyby before it hits, you can deflect it if you change its velocity by a fraction of a meter per second, which is something that's practical even with a kilometer scale asteroid. And with nuclear weapons, the very largest, thousand kilotons weapons, we can push asteroids out of their course or totally disintegrate them even with just a few years of warning.
So, it is important to protect ourselves from asteroids, just as it is for tsunamis and earthquakes, but with the unique thing that we can actually prevent an asteroid impact, while so far anyway, we have no way to prevent an earthquake or an earthquake caused tsunami.
So in some ways asteroid impacts are notable as the most easily prevented and "tameable" of all the natural disasters. We don't need to worry that they will make us extinct, we should instead be focusing our efforts on detecting and preventing them. With enough investment into the technology, then we could make sure that this can't happen.
And that would cost far less than any attempt to set up a space colony "backup" on Mars which in any case is in the wrong place, as if anything did happen to Earth, well the only obvious place to reconstruct civilization is back here on Earth, so you want your backup to be here, as close to Earth as possible.
This is NASA's priority for asteroid impacts - to find them and deflect them, as it is with all the international partners in the search for asteroids.
The idea that we need to make a backup of Earth in space is not currently a stated NASA policy or aim. And I don't think it should be, myself.
Even if Mars could be terraformed, which many doubt - that's a plan that can only provide something even approximately like Earth (probably still requiring aqualung like air breathers to get around, especially since only small concentrations of 1% or more of CO2 can kill a human).
At least that's the best we can hope for, for thousands of years, probably hundreds of thousands of years into the future. And no way that it can be at all "Earth-like" right now. So far too late to help with anything that goes wrong in this century, or the next, or the next ten centuries even.
Also, after any disaster that happens to Earth, your first priority would be to come back to Earth and help rebuild it.
I think myself, it makes most sense to have tour backups on Earth itself, multiple backups in different places on the surface, if you think that is important, and you are sorted.
Also this idea of "backing up" in space - I think can lead people to feel that it is time to give up on the Earth and start again elsewhere. As if we wouldn't make the same mistakes again elsewhere. And that it could lead them to stop putting so much effort into the efforts to preserve our Earth's habitability.
If we went extinct, that would as likely be the result of our technology as otherwise. Any space colonies would be the most technological outposts of humanity, continually working with and evolving new technologies. For instance 3D printers, self replicating machines etc. Also anyone with the capability to go into space has technology far more capable than ICBMs.
So if done carelessly, without care taken for peaceful co-operation in space, then attempts to colonize would as likely be the cause of our extinction as save us from it.
We have managed to explore peacefully so far. But if we start to have independent nation states in space, that might not be so easy. If the main risk to us continuing as a species is high technology warfare, well colonies in space would probably make that worse. And if the main risk is the technology itself, again they'd make it worse if anything. If the risk is a disease, well with fast transport, then there wouldn't be anything to stop it spreading to or from space colonies. If quarantine is the solution, we can do that as easily on Earth as in space.
I think we can explore space peacefully, and have made an excellent start on it. But we don't need to go all out to establish new nations in space as our first priority. If exploration and science is our priority, we can let any settlement, if it happens, occur naturally as an outcome from that.
And the Earth is by far the most habitable planet in our solar system and will be for the foreseeble future. There is nothing that could make it anything like as uninhabitable as Mars.
So, if there is any chance that humans could accidentally introduce life to Mars, and confuse the scientific studies of Mars by the USA but also by all other space faring nations, then there is no way we should send humans there.
NASA has a planetary protection office devoted to protecting the planets from contamination from Earth life. They seem to think that they can explore Mars with humans without contaminating it with Earth life. Some years back, you could argue that there is no chance at all of life on the surface, and that humans on the surface might be sufficiently insulated from subsurface life that they couldn't contaminate it.
But now, that argument is rather harder to put. Because there are many potential habitats now suggested, where liquid water could form on the surface of Mars. If these habitats do exist, then I'm sure NASA like everyone else will agree that we have to keep humans away from them.
Then, the next question is, can you send humans to one part of Mars, and then robots only to other parts, and so keep the humans away from the habitats where life could exist. That seems to be the current NASA plan for the future.
But the main issue with that is, that Mars is a connected surface, with global dust storms. Those dust storms would protect life from the UV radiation.
This was pointed out by Carl Sagan long ago, iron oxides are good at filtering out UV light so a microbe in a dormant state, imbedded in a crack in a grain of Martian dust would be protected from the sunlight, and could be blown anywhere on the surface of Mars - for that matter the dust storms block out nearly all the light anyway when they are at their thickest).
A human mission to the surface also could well crash land. A hard landing would end with human bodies and food and water and the air spread out over the surface. So far about half of all landings on Mars have crashed in one way or another. And - you are talking about an order of magnitude increase in complexity to send humans there. Surely some of the ships would crash. Landing even four uninhabited habitats safely first would prove nothing - with a 50 / 50 chance of crashing, then there is a 1 in 16 chance of landing successfully four times in succession. Even ten successful landings one after another would not prove that your chances for the next landing is better than 1 in 2.
After a human crash landing on Mars, then any life you found on Mars after that, your first guess would be that it came from that crash landing.
And - I don't see any advantage of humans on the surface myself for the search for life. They can't drill better than robots - ever seen the video of the astronauts drilling on the Moon? In spacesuits? Robots can use robotic moles and those in principle can drill down kilometers (moles work better than conventional drilling because you can't use water to lubricate the drill on Mars because of the vacuum atmosphere).
As for any habitats for life on Mars, then if they exist, then in the NASA plans - humans would go nowhere near them, for planetary protection reasons, and also, because then they'd as likely only detect Earth life. So they'd be operating the robots remotely anyway for all the most interesting searches. They have outlined ideas where the humans land many kilometers away from the places of interest for life. Then robots travel from the human habitats to explore them, and bring back samples for the humans to study.
So why not do that from orbit instead? It saves all the danger of the landing on Mars, no need for a human rated lander, no need to develop rovers to carry humans on the surface, along with oxygen and provisions. No need for Mars rated spacesuits, or protection from the Mars dust. Shirt sleeves environment from space. And it removes what seems an unnecessary extra increase in risk of contaminating the habitats with Earth life.
Here I'm of course presenting just one view on the matter.
But however they do it, one way or another any NASA astronauts to Mars, indeed any astronauts from any country, including private astronauts, will have to show that they are complying with the planetary protection requirements.
Private citizens also have to do this, because, just as with quarantine rules, the planetary protection rules apply to you, no matter how you get into space. And it is the responsibility for your country of citizenship to enforce these rules - also anyone who supplies you with equipment, such as spaceships, rockets, oxygen equipment or whatever, is also bound by these rules, they are required to make sure that the expedition they are supporting is in accord with the treaty.
There's a potential conflict of interests here, as Max Jones said. But it is one where if habitats for Earth life exist there, the colonists would probably irreversibly change Mars as it's hard to see how you could remove a microbe from a planet once it has "set up home" there, unless very localized. While those who advocate planetary protection are not doing anything irreversibly, but just keeping the options open for the future.
At the very least we'd need to investigate many examples of all the potential habitats suggested for present day life on Mars. Because, life on Mars might not be able to spread easily to new habitats, some may remain uninhabited for long periods of time. So if you find no life in a particular type of habitat, you won't be able to deduce, right away, that there is no life in that type of habitat over the whole of Mars.
Current scientific views span a wide spectrum, from those who are skeptical about the possibility of finding any life on the Mars surface, to those who think it is quite likely.
Nilton Remmo - a project scientist for Curiosity in charge of the REMS weather station on Mars - is an example of someone who is optimistic about our prospects for finding present day life there. He thinks there is a reasonable chance that there are droplets of water on Mars on salt / ice interfaces (as a result of Mars simulation experiments) and that there may be life in those droplets.
If we want to send humans in space - and I think humans do have a role to play in space - well our moon is the first and most obvious target. Barely explored on the surface, and there are many limitations to what we can find out from orbit. We've only had one scientist visit the Moon - the rest were all jet fighter pilots by training, with a small amount of geology field trips, but they were not scientists, they were chosen for their fast reactions, ability to stay calm in a crisis and such like qualities. And the live video feed was low quality and in black and white so not easy for those on the ground to assess what it was they could see.
So basically we've had a single "field expedition" to the Moon, to just one spot and by one scientist with one non scientist helper - plus several reconnaissance visits by non scientists who took various scientific packages there, and the rocks they brought back. Though we learnt a lot from these visits, it's no surprise that it wasn't enough to get a thorough understanding of what the Moon is like.
The Moon is turning out to be far more interesting than we thought in the 1960s and 1970s. With discoveries of probable ice at the poles - layers of ice preserving the history of the solar system. Caves, which may be huge, even large enough for cities inside them. Best place to build radio telescopes on the far side of the Moon. Predicted to have meteorites from the early Earth, even before the earliest rocks we know of on Earth, if we dig for them. Lots of reasons to go there.
And for Mars then once we have the capabilities to send humans that far, journeys of years rather than days of travel to get back to Earth - then the obvious thing is to send humans to orbit, or to Phobos and Deimos. And to explore the surface via telerobotics.
I know that is not NASA's current policy but think, as they work through the implications for planetary protection, especially in the event of a hard landing on Mars, that this is bound to be the final decision. That is unless they discover that the surface of Mars is totally sterile for life. But there is a decent chance, at present anyway, for the much more interesting possibility that there actually are habitats there.
Microbes by themselves are not especially interesting except to microbiologists. But microbes that have evolved independently of Earth life, whether they have a common origin billions of years ago or not, those are of great interest to biology generally. And that's the main reason, for most scientists, why Mars is of special interest to explore, and the main reason why we have sent so many more missions to Mars than any other planet.
The most exciting thing would of course be non DNA based life. But I think DNA based life would be very interesting on Mars also. First, it's likely to be a precursor of modern life, or to have branched off in the first few hundred million years of the solar system as that is when there was most transfer. Or indeed, originated on Mars then come to Earth. So it might show us how some of the immense complexity of DNA based life started to arise from simpler earlier microbes.
Also, even if it is more recently related, then still it has evolved for probably hundreds of millions, or billions of years on a planet with almost no atmosphere, huge amounts of radiation, CO2 atmosphere with no oxygen, perchlorates abundant, colder temperatures etc etc. Those are conditions that are not available anywhere on Earth. It would almost certainly be at least as interesting as life in hydrothermal vents, even if closely related. And if there is no life there, but complex chemistry instead - a chemistry that has developed over billions of years on a planet without life - well that is of huge interest also. What does happen on a planet left for billions of years, with organics and without life? Especially if it has present day uninhabited habitats, I think those also could be of huge interest for exobiology.
So to answer the question, NASA have to care about finding life on Mars, that's mandated by the OST. And - they are also influenced by the colonization advocates, such as the Mars Society who are particularly strong in the US. So they are trying to pursue a policy that satisfies both.
So far that's been possible. But in future I think there may be conflicts. If so, they are tasked with protecting Mars from Earth life, and there would also be considerable international pressure on them from scientists world wide to do that, and scientists in NASA also would not want to explore the Mars surface with humans if they felt that would jeopardize the search for life there.
If there is a conflict like that, this would delay human colonization for sure. And some scientists at least, such as Chris McKay, say that if we do find independently evolved life on Mars, that we should reverse all the contamination we have done there already - and leave Mars to the microbes. And perhaps even, try to restore the earlier Mars with conditions favourable to the Mars life whatever it is, rather than for us.
There are many other places in the solar system for human colonization. Including the Moon, the upper Venus atmosphere, or converting the asteroid belt into Stanford Torus type habitats. That last is in many ways the most promising of all, dates back to a 1970s calculation there's enough material in the asteroid belt to make habitats with total living area a thousand times the land surface of the Earth. We could make copies of Mars, of Earth, of interesting exoplanets, of a thousand different planets, entire surface, just using materials from the asteroid belt.
But all of these places are far less habitable than even the most inhospitable deserts on Earth. So once we have the technology for space colonies like that, we'd also be able to "set up home" in any desert and colonize it using just the desert sand and the moisture in the atmosphere - with a big head start of course that we don't need spacesuits and can breath the atmosphere.
See also my Science20 articles:
They are pursuing both at once at present, though all the missions to Mars so far have had the search for life as their top priority.
US is a signatory of the Outer Space Treaty. As such it has committed itself to
Article IX: ... States Parties to the Treaty shall pursue studies of outer space, including the Moon and other celestial bodies, and conduct exploration of them so as to avoid their harmful contamination and also adverse changes in the environment of the Earth resulting from the introduction of extraterrestrial matter and, where necessary, shall adopt appropriate measures for this purpose..
There harmful contamination has been taken to include contamination that interferes with the scientific activities of other parties to the treaty.
For more on this, see Planetary protection
They would in any case be shooting themselves in the foot if they introduce life to Mars. Because the most interesting thing about Mars is to find out if there was past life there, and if there still is life there.
NASA ARE DOING BOTH AT ONCE AS BEST THEY CAN
With Curiosity's successor they will be sending the first ever experiment sent to Mars which arguably has colonization as the main motivation for including it - the Moxie instrument to generate oxygen on Mars - it has no value at all for the search for life, and it just adds extra mass for the rover to carry around with it, and it doesn't even make any use of the oxygen which will be discarded into the atmosphere after it is generated.
I think that is a good example of them trying to follow both goals at once.
DINOSAURS DIDN'T HAVE TELESCOPES OR SUBMARINES OR FIREPROOF SHELTERS
Many people say that we need to send humans into space as a backup plan for Earth, famously of course Elon Musk. But this is not NASA's stated objective at all.
There is no significant risk of us going extinct on the Earth in the next few hundred million years, except by our own actions. The dinosaurs didn't have telescopes and had no way to deflect asteroids. If they did, they could have spotted something that large from the other side of the solar system (it was as large as Mars's outer moon Deimos). It would surely have done many flybys of Earth also because the Earth is a tiny target, before it hit.
And for that matter, they had no way to escape from its effects. Couldn't dig underground or build fireproof shelters, or stockpile food, or use submarines or boats or planes to escape. And there's only one in a million chance of such an impact in the next century. And other suggested disasters are first, even less likely, and also, would be similarly survived by a large fraction of our population with technology.
DETECTING AND DEFLECTING ASTEROIDS
With our technology we can also not just detect asteroids but also divert them. There are many more of the smaller asteroids than larger ones. So it's almost certain that the first asteroids predicted to hit Earth will be of the scale of a hundred meters max, rather than the huge kilometer sized or larger ones of the asteroid scare stories you read. And the larger ones, we'd almost certainly spot thousands of years in advance, with many close flybys of Earth first. Even if there is just one close flyby before it hits, you can deflect it if you change its velocity by a fraction of a meter per second, which is something that's practical even with a kilometer scale asteroid. And with nuclear weapons, the very largest, thousand kilotons weapons, we can push asteroids out of their course or totally disintegrate them even with just a few years of warning.
So, it is important to protect ourselves from asteroids, just as it is for tsunamis and earthquakes, but with the unique thing that we can actually prevent an asteroid impact, while so far anyway, we have no way to prevent an earthquake or an earthquake caused tsunami.
So in some ways asteroid impacts are notable as the most easily prevented and "tameable" of all the natural disasters. We don't need to worry that they will make us extinct, we should instead be focusing our efforts on detecting and preventing them. With enough investment into the technology, then we could make sure that this can't happen.
And that would cost far less than any attempt to set up a space colony "backup" on Mars which in any case is in the wrong place, as if anything did happen to Earth, well the only obvious place to reconstruct civilization is back here on Earth, so you want your backup to be here, as close to Earth as possible.
This is NASA's priority for asteroid impacts - to find them and deflect them, as it is with all the international partners in the search for asteroids.
The idea that we need to make a backup of Earth in space is not currently a stated NASA policy or aim. And I don't think it should be, myself.
WHY MARS CAN'T BE A BACKUP RIGHT NOW
Even if Mars could be terraformed, which many doubt - that's a plan that can only provide something even approximately like Earth (probably still requiring aqualung like air breathers to get around, especially since only small concentrations of 1% or more of CO2 can kill a human).
At least that's the best we can hope for, for thousands of years, probably hundreds of thousands of years into the future. And no way that it can be at all "Earth-like" right now. So far too late to help with anything that goes wrong in this century, or the next, or the next ten centuries even.
Also, after any disaster that happens to Earth, your first priority would be to come back to Earth and help rebuild it.
I think myself, it makes most sense to have tour backups on Earth itself, multiple backups in different places on the surface, if you think that is important, and you are sorted.
Also this idea of "backing up" in space - I think can lead people to feel that it is time to give up on the Earth and start again elsewhere. As if we wouldn't make the same mistakes again elsewhere. And that it could lead them to stop putting so much effort into the efforts to preserve our Earth's habitability.
TECHNOLOGY, INCLUDING SPACE COLONIES - A TWO EDGED SWORD
If we went extinct, that would as likely be the result of our technology as otherwise. Any space colonies would be the most technological outposts of humanity, continually working with and evolving new technologies. For instance 3D printers, self replicating machines etc. Also anyone with the capability to go into space has technology far more capable than ICBMs.
So if done carelessly, without care taken for peaceful co-operation in space, then attempts to colonize would as likely be the cause of our extinction as save us from it.
We have managed to explore peacefully so far. But if we start to have independent nation states in space, that might not be so easy. If the main risk to us continuing as a species is high technology warfare, well colonies in space would probably make that worse. And if the main risk is the technology itself, again they'd make it worse if anything. If the risk is a disease, well with fast transport, then there wouldn't be anything to stop it spreading to or from space colonies. If quarantine is the solution, we can do that as easily on Earth as in space.
I think we can explore space peacefully, and have made an excellent start on it. But we don't need to go all out to establish new nations in space as our first priority. If exploration and science is our priority, we can let any settlement, if it happens, occur naturally as an outcome from that.
And the Earth is by far the most habitable planet in our solar system and will be for the foreseeble future. There is nothing that could make it anything like as uninhabitable as Mars.
So, if there is any chance that humans could accidentally introduce life to Mars, and confuse the scientific studies of Mars by the USA but also by all other space faring nations, then there is no way we should send humans there.
PLANETARY PROTECTION
NASA has a planetary protection office devoted to protecting the planets from contamination from Earth life. They seem to think that they can explore Mars with humans without contaminating it with Earth life. Some years back, you could argue that there is no chance at all of life on the surface, and that humans on the surface might be sufficiently insulated from subsurface life that they couldn't contaminate it.
But now, that argument is rather harder to put. Because there are many potential habitats now suggested, where liquid water could form on the surface of Mars. If these habitats do exist, then I'm sure NASA like everyone else will agree that we have to keep humans away from them.
SENDING HUMANS TO BIOLOGICALLY UNINTERESTING PARTS OF MARS ONLY (FOR CURRENT LIFE ANYWAY)
Then, the next question is, can you send humans to one part of Mars, and then robots only to other parts, and so keep the humans away from the habitats where life could exist. That seems to be the current NASA plan for the future.
But the main issue with that is, that Mars is a connected surface, with global dust storms. Those dust storms would protect life from the UV radiation.
This was pointed out by Carl Sagan long ago, iron oxides are good at filtering out UV light so a microbe in a dormant state, imbedded in a crack in a grain of Martian dust would be protected from the sunlight, and could be blown anywhere on the surface of Mars - for that matter the dust storms block out nearly all the light anyway when they are at their thickest).
CRASH LANDINGS ON MARS BY HUMANS
A human mission to the surface also could well crash land. A hard landing would end with human bodies and food and water and the air spread out over the surface. So far about half of all landings on Mars have crashed in one way or another. And - you are talking about an order of magnitude increase in complexity to send humans there. Surely some of the ships would crash. Landing even four uninhabited habitats safely first would prove nothing - with a 50 / 50 chance of crashing, then there is a 1 in 16 chance of landing successfully four times in succession. Even ten successful landings one after another would not prove that your chances for the next landing is better than 1 in 2.
After a human crash landing on Mars, then any life you found on Mars after that, your first guess would be that it came from that crash landing.
And - I don't see any advantage of humans on the surface myself for the search for life. They can't drill better than robots - ever seen the video of the astronauts drilling on the Moon? In spacesuits? Robots can use robotic moles and those in principle can drill down kilometers (moles work better than conventional drilling because you can't use water to lubricate the drill on Mars because of the vacuum atmosphere).
OPERATING ROBOTS REMOTELY ON MARS - WHY NOT DO FROM ORBIT?
As for any habitats for life on Mars, then if they exist, then in the NASA plans - humans would go nowhere near them, for planetary protection reasons, and also, because then they'd as likely only detect Earth life. So they'd be operating the robots remotely anyway for all the most interesting searches. They have outlined ideas where the humans land many kilometers away from the places of interest for life. Then robots travel from the human habitats to explore them, and bring back samples for the humans to study.
So why not do that from orbit instead? It saves all the danger of the landing on Mars, no need for a human rated lander, no need to develop rovers to carry humans on the surface, along with oxygen and provisions. No need for Mars rated spacesuits, or protection from the Mars dust. Shirt sleeves environment from space. And it removes what seems an unnecessary extra increase in risk of contaminating the habitats with Earth life.
Here I'm of course presenting just one view on the matter.
But however they do it, one way or another any NASA astronauts to Mars, indeed any astronauts from any country, including private astronauts, will have to show that they are complying with the planetary protection requirements.
Private citizens also have to do this, because, just as with quarantine rules, the planetary protection rules apply to you, no matter how you get into space. And it is the responsibility for your country of citizenship to enforce these rules - also anyone who supplies you with equipment, such as spaceships, rockets, oxygen equipment or whatever, is also bound by these rules, they are required to make sure that the expedition they are supporting is in accord with the treaty.
There's a potential conflict of interests here, as Max Jones said. But it is one where if habitats for Earth life exist there, the colonists would probably irreversibly change Mars as it's hard to see how you could remove a microbe from a planet once it has "set up home" there, unless very localized. While those who advocate planetary protection are not doing anything irreversibly, but just keeping the options open for the future.
At the very least we'd need to investigate many examples of all the potential habitats suggested for present day life on Mars. Because, life on Mars might not be able to spread easily to new habitats, some may remain uninhabited for long periods of time. So if you find no life in a particular type of habitat, you won't be able to deduce, right away, that there is no life in that type of habitat over the whole of Mars.
Current scientific views span a wide spectrum, from those who are skeptical about the possibility of finding any life on the Mars surface, to those who think it is quite likely.
Nilton Remmo - a project scientist for Curiosity in charge of the REMS weather station on Mars - is an example of someone who is optimistic about our prospects for finding present day life there. He thinks there is a reasonable chance that there are droplets of water on Mars on salt / ice interfaces (as a result of Mars simulation experiments) and that there may be life in those droplets.
ROLE FOR HUMANS
If we want to send humans in space - and I think humans do have a role to play in space - well our moon is the first and most obvious target. Barely explored on the surface, and there are many limitations to what we can find out from orbit. We've only had one scientist visit the Moon - the rest were all jet fighter pilots by training, with a small amount of geology field trips, but they were not scientists, they were chosen for their fast reactions, ability to stay calm in a crisis and such like qualities. And the live video feed was low quality and in black and white so not easy for those on the ground to assess what it was they could see.
So basically we've had a single "field expedition" to the Moon, to just one spot and by one scientist with one non scientist helper - plus several reconnaissance visits by non scientists who took various scientific packages there, and the rocks they brought back. Though we learnt a lot from these visits, it's no surprise that it wasn't enough to get a thorough understanding of what the Moon is like.
The Moon is turning out to be far more interesting than we thought in the 1960s and 1970s. With discoveries of probable ice at the poles - layers of ice preserving the history of the solar system. Caves, which may be huge, even large enough for cities inside them. Best place to build radio telescopes on the far side of the Moon. Predicted to have meteorites from the early Earth, even before the earliest rocks we know of on Earth, if we dig for them. Lots of reasons to go there.
And for Mars then once we have the capabilities to send humans that far, journeys of years rather than days of travel to get back to Earth - then the obvious thing is to send humans to orbit, or to Phobos and Deimos. And to explore the surface via telerobotics.
I know that is not NASA's current policy but think, as they work through the implications for planetary protection, especially in the event of a hard landing on Mars, that this is bound to be the final decision. That is unless they discover that the surface of Mars is totally sterile for life. But there is a decent chance, at present anyway, for the much more interesting possibility that there actually are habitats there.
WHY MICROBES ON MARS ARE INTERESTING
Microbes by themselves are not especially interesting except to microbiologists. But microbes that have evolved independently of Earth life, whether they have a common origin billions of years ago or not, those are of great interest to biology generally. And that's the main reason, for most scientists, why Mars is of special interest to explore, and the main reason why we have sent so many more missions to Mars than any other planet.
The most exciting thing would of course be non DNA based life. But I think DNA based life would be very interesting on Mars also. First, it's likely to be a precursor of modern life, or to have branched off in the first few hundred million years of the solar system as that is when there was most transfer. Or indeed, originated on Mars then come to Earth. So it might show us how some of the immense complexity of DNA based life started to arise from simpler earlier microbes.
Also, even if it is more recently related, then still it has evolved for probably hundreds of millions, or billions of years on a planet with almost no atmosphere, huge amounts of radiation, CO2 atmosphere with no oxygen, perchlorates abundant, colder temperatures etc etc. Those are conditions that are not available anywhere on Earth. It would almost certainly be at least as interesting as life in hydrothermal vents, even if closely related. And if there is no life there, but complex chemistry instead - a chemistry that has developed over billions of years on a planet without life - well that is of huge interest also. What does happen on a planet left for billions of years, with organics and without life? Especially if it has present day uninhabited habitats, I think those also could be of huge interest for exobiology.
So to answer the question, NASA have to care about finding life on Mars, that's mandated by the OST. And - they are also influenced by the colonization advocates, such as the Mars Society who are particularly strong in the US. So they are trying to pursue a policy that satisfies both.
So far that's been possible. But in future I think there may be conflicts. If so, they are tasked with protecting Mars from Earth life, and there would also be considerable international pressure on them from scientists world wide to do that, and scientists in NASA also would not want to explore the Mars surface with humans if they felt that would jeopardize the search for life there.
If there is a conflict like that, this would delay human colonization for sure. And some scientists at least, such as Chris McKay, say that if we do find independently evolved life on Mars, that we should reverse all the contamination we have done there already - and leave Mars to the microbes. And perhaps even, try to restore the earlier Mars with conditions favourable to the Mars life whatever it is, rather than for us.
There are many other places in the solar system for human colonization. Including the Moon, the upper Venus atmosphere, or converting the asteroid belt into Stanford Torus type habitats. That last is in many ways the most promising of all, dates back to a 1970s calculation there's enough material in the asteroid belt to make habitats with total living area a thousand times the land surface of the Earth. We could make copies of Mars, of Earth, of interesting exoplanets, of a thousand different planets, entire surface, just using materials from the asteroid belt.
But all of these places are far less habitable than even the most inhospitable deserts on Earth. So once we have the technology for space colonies like that, we'd also be able to "set up home" in any desert and colonize it using just the desert sand and the moisture in the atmosphere - with a big head start of course that we don't need spacesuits and can breath the atmosphere.
See also my Science20 articles:
- Trouble With Terraforming Mars
- Ten Reasons NOT To Live On Mars - Great Place To Explore
- Why We Can't "Backup Earth" On Mars, The Moon, Or Anywhere Else In Our Solar System
- Why Elon Musk's Colony on Mars in 2020s is Unfeasible - What Could We Do - Really?
- Will We Meet ET Microbes On Mars? Why We Should Care Deeply About Them - Like Tigers
- Might there be Microbes on the Surface of Mars?
- Imagined Colours Of Future Mars - What Happens If We Treat A Planet As A Giant Petri Dish?
- To Explore Mars With Likes Of Occulus Rift & Virtuix Omni - From Mars Capture Orbit, Phobos Or Deimos
- How Valuable is Pristine Mars for Humanity - Opinion Piece?
- How Life May Exist On Mars With Atmosphere Close To Equilibrium
- Does Earth Share Microbes With Mars Via Meteorites - Or Are They Interestingly Different For Life?
- Habitability Of Mars - Salty Seeps, Liquid Layers In Polar Ice, Ice Fumaroles, Sand Dune Bioreactors. ...
- Where To Search On Mars For Droplets, & Shallow Flows Of Liquid Water - Where Microbial Life May Flourish
- Asteroid Resources Could Create Space Habs For Trillions; Land Area Of A Thousand Earths
- and quite a few more on this general topic
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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