Water seems to flow freely on Mars | Hacker News Reader

Water seems to flow freely on Mars

nature.com

275 pointscryptoz161 comments

Is anyone else tired of hearing about the dangers of interplanetary contamination, particularly from the Earth to Mars? I want to see the whole place terraformed and I can't imagine that we'd be so successful in our lifetimes that we'd wipe out whatever scientifically interesting traces of extant Martian flora there are. Whether or not there was life on Mars is a fascinating question, but I think the more important one is when will we expand life on Mars?

right, this is pretty much the attitude with which colonial powers approached new continents. The universe was not built for humans alone - if there is life there - which in its current form is unable to protect itself - it is our duty to protect it and leave it untouched - not kill it in hordes and put the remaining few in reserves and allow them to open casinos as a consolation prize.

EDIT: On the other hand - if it is life that can protect itself - i.e. - attack human explorers or cause unintentional harm to them - then we also need to be able to understand that in an isolated environment before we just touchdown and put up our IKEA stuff..

Though if we do put martian bacteria in reservations en masse, I call dibs on teaching them how craps works.

We're not talking indigenous tribes here; its maybe some (unsuccessful) bacteria. You willfully destroy these every time you use mouthwash.

Lets not get all PC about some stains on some dirt on a rock somewhere.

You're implying that the inside of your mouth and the landscape of Mars are more or less equivalent?

Bone dry and dangerous to breathe describes my mouth some mornings.

I dont see your point apart from trying to sound as nasty as possible? Just because they arent tribes means they're irrelevant? They are indigenous species and should be protected in the interest of science if nothing else. You dont eliminate every bacteria of a certain species when you use mouthwash. In the grand scheme of things we are also just some stains on some dirt on a rock somewhere.

You're projecting. I just don't value a few struggling bacteria the same way you do.

In the interest of science, you can keep some on your desk in a petri dish. As for the rest of mankind, we'll be using all the resources in our solar system that are available. The future belongs to a system-spanning culture that will terraform, relocate and resurface every available rock we find to make more space for life.

While your techno-optimism is very inspiring, I'd rather not be the victim of a solar system black plague either. On the other hand, since we're speculating, I'm looking forward to the one piece of "dirt on a rock" somewhere that can make me immune to radiation while on my space voyage.

You're assuming that they'd a few struggling bacteria - and that all of mankind wants to quit earth and spread as far and wide as possible. Both of which is basically bullshit. If anything - our population is heading towards its peak - which will follow with a sinking population. A majority of the developed world is greying - these are people who would have access to plenty of space and resources for their offspring - choosing not to have more. So I guess since you've taken on the role of the spokesperson for the "rest of mankind" - you might want to check in and see if humans are really that eager to go live on every rock in the solar system - or are fine where they are.

I don't have to run a poll. There's me, and folks like me. That's enough. Colonization never means 'most folks'; it always means only those willing to take risks and try something new. So your greying, senescent population can go ahead and stay at home without affecting anything regarding mankind's future.

I strongly suspect that if you took a poll, you would find that the real shortage will be a shortage of seats on rockets, not people to fill them. Even if people with a suitable exploratory attitude are one in a million, that still gives you thousands of volunteers.

Not if they have to pay it themselves

Yes, even if they have to pay for it themselves. Someone interested in being an off-world colonist will have little use for earth assets; they could liquidate everything. Even if you peg it at tens of millions, you would still have more willing volunteers than rocket seats for the foreseeable future.

Though I am not sure why you assume that would necessarily be the scenario..

It seems as though you think he's alone in voicing the least bit of concern for the fact that it might be valuable to hold up a second before steamrolling the (hypothetical) only extraterrestrial life we've discovered in the universe in the pursuit of a future which to me sounds, quite frankly, disgusting. Claiming that mankind shares your views en masse and furthermore making declarative statements about who "owns" the future is a monument to hubris and quite possibly a solid example of the projection you accuse others of.

I can't wait for the time when a new super intelligent alien race comes on earth and exterminates us all because to them we look just like a bunch of lichens under a rock. That's definitely the way to go.

Yeah; until then are you going to stop using mouthwash? Stop washing your hands? This is just a silly conversation.

That depends. Could it increase the possibility of discerning the existence of extraterrestrial life and of being able to study it in it's natural habitat if I don't?

But it's really not a silly conversation. You are comparing (assuming it exists) the only extra terrestrial life we have ever found. Literally alien life.

Mouthwash bacteria doesn't mean a thing when you kill it because it's bacteria and it originated on earth. Bacteria that originated on Mars would be completely different as we'd study it for years just to find out how it originated and survives.

We don't even know they are there to begin with. I am all for proceeding carefully, but you're arguing for a paralysis of ignorance.

No, it doesn't mean they're irrelevant, it just means your previous analogy is irrelevant.

"The human body contains over 10 times more microbial cells than human cells, although the entire microbiome only weighs about 200 grams (7.1 oz), with some weight estimates ranging as high as 3 pounds (approximately 48 ounces or 1,400 grams)." [0]

You would literally not be the same animal you are now had bacteria not helped you along the way.

[0]http://en.wikipedia.org/wiki/Microbiome

You would be dead without the bacteria you have to help you along. But I'm not sure how this relates to a planet where said bacteria, if they exist, are sitting at the top of the biological pyramid.

Yeah, funny thing "defending" bacteria. I guess my point is that very simple organisms can have large a impact (on us, given the anthropocentric view I'm replying to here). Viruses for instance.

In a vibrant ecosystem, sure. But Mars is a dessicated husk of what might once have been a green thriving world. These remaining bacteria/fungi/whatever are like bugs on a corpse. Not an ecosystem; a fragment of a perhaps once-complex ecosystem and worth study. But not anything that should prevent or delay exploration of a planet.

Hopefully :)

I agree 100% with you, but it would be pretty embarrassing for top NASA scientists to report they have "found life on mars", only to later realize that it was life that the spacecraft brought from earth...

Better to decontaminate the spacecraft, have it take samples/perform measurements, then it can open a can of "life-from-earth" microbes and release them to the Mars surface.

Why terraform, then? Why not mine the hell out of the place right away? Are you really in such a hurry to get off this planet? Isn't it much more important to learn a bit about the world before we start shaping it in our image?

"Isn't it much more important to learn a bit about the world before we start shaping it in our image?"

Gonna have to go with, no.

There are over 6 billion monkeys on this planet, and the clock is ticking on what's left of our resources. Either we move some of the monkeys, or we remove some of the monkeys.

Or the monkeys learn to live with what they have.

I highly doubt that colonization of other planets will result in significant numbers of monkeys being moved from earth to somewhere else, and even if that were the case, how long before we now have two planets crawling with monkeys who still haven't figured out how to control themselves?

Long enough to get to a 3rd planet.

Interesting, your view of extraterrestial lifeforms is very similar to the approach of colonists in the 18th and 18th centuries - that the people/lifeforms being invaded were inferior to the colonists, and hence could be mistreated/mutilated/wiped out for the benefit of the invaders.

Thankfully, scientists are not of this mindset.

We basically have one shot, per body in the solar system, to find an example of life with an independent abiogenesis point. Right now biology only gets to work with a single example; the impact that finding another would have on the field really cannot be understated^W overstated.

Now, you may not be particularly interested in biology, preferring space travel, but you should be. Any realistic attempt to terraform Mars will require a lot of skill with genetic engineering. Furthermore, the discovery of life that can only be properly studied on Mars would provide a major boost to any colonization effort. The more 'kinds of science we use to justify the initial expenditure, the better.

The one shot for Mars may have been missed, millennia ago, when rocks blasted from Earth landed on Mars.

On the geologic scale things get knocked around a lot.

Even if we suppose that panspermia is likely, it is still important that we avoid cross-contamination ourselves. Discovering that panspermia took place through natural processes would tell us a lot about how prevalent and resilient life may be in the universe. Furthermore, two instances of life with the same abiogenesis point, isolated and diverged sometime in the past, would be very valuable for biologists.

Furthermore, two instances of life with the same abiogenesis point, isolated and diverged sometime in the past, would be very valuable for biologists.

Isn't this something you can basically get on Earth? Perspermia doesn't really seem to be required.

To a limited degree, yes. Biologists study divergence of isolated species all the time; panspermia would give us a difference in degree, not kind.

You're both right. Yes, we should check very carefully, but as you point out we have more than one body to play with. We should have a clearly defined cutoff point at which we stop looking for something that may not be there in the first place and do other things instead. Otherwise we're never going to get off the planet.

As these things go, Mars is far less interesting to me than Europa. That moon of Jupiter seems to have massive amounts of liquid water, geysers, ice quakes and plate tectonics, (presumably due to) tidal forces from Jupiter, and a thin oxygen atmosphere. Along with Saturn's moon Enceladus, it's the most promising place to look for other forms of life.

http://en.wikipedia.org/wiki/Europa_(moon) http://en.wikipedia.org/wiki/Enceladus_(moon)

There is more than one body to play with, but Mars is among the better chances that we have (and I'd say certainly the easiest chance. Europa is the best chance, but it is not exactly easy to get out there).

Of course we need some sort of cutoff for how cautious we need to be, even if we do embrace caution. Slapping a McMurdo style base down on Mars so that biologists could work more efficiently would risk contaminating the planet, but I think that is a risk we should take (once we have confirmed that there is life there, it would probably be reasonable to loosen controls).

Seems we're ont he same page. In discussions like this my comments are partly tinged with frustration about how much more we could be doing at relatively modest cost, though activities int he private sector and from countries like China and India are greatly encouraging. I want the space colonies I was promised, dammit.

I wish humanity could fix its memory leaks before it goes out to buy more sticks of RAM.

Regardless of whether we fix the memory leak or buy more RAM we are still running our production service on a single server, and could do with a high-availability setup.

Either way, our deployment process to new servers leaves something to be desired.

We keep trying to automate it but the PHBs keep on shutting down project after project.

That's just begging the question. The whole point here is that we shouldn't need "science" to somehow "justify" the colonization of Mars. Saying that it's a good thing because it "justifies" expenditure, is like saying that it was good for Hitler to continue WW2 because that's what incentivised the US to invade Europe: pragmatically it's correct, but pragmatism is really not what's debated here.

Personally I would like to see the priorities of "colonization vs science" reversed.

The expenditure does not need to be justified to people like you or me; it is obvious to us that we should colonize Mars even if it is currently a dead sterile rock. Sadly however I have not yet become emperor (work in progress), and funding for space exploration often requires short-term tangible justifications. This becomes more true the more expensive it gets.

From a pragmatic standpoint, it is important that any life that may be on Mars is discovered so that we can use those results to push for more funding. Anything that could accelerate the process should be investigated.

If that is unsatisfactory for you, I'll point out again that it isn't just a matter of politics and funding. The discovery and study of non-Earth life would provide countless opportunities for the advance of biology. An advanced understanding of biology is essential to the core mission of colonizing and terraforming Mars, even if I am made emperor.

I agree, but what you are saying is "assuming the status-quo, let's see if we can find something good about it". Whereas I'm saying: you might be right, but the status quo is still wrong, and we shouldn't be happy about it being wrong.

Concerning your last paragraph - while it may be true, I'm pretty sure that gaining terraforming-related knowledge plays a very minor role in NASA's research decisions, which is also something we shouldn't be happy about.

Anything that we learn of biology will help with the eventual terraforming. That is not the sort of thing that necessarily needs to be researched directly right now, researching things in general expands our knowledge base, giving something for terraforming research to stand and build on.

Blimey Charlie, I definitely wasn't expecting this discussion thread to be Godwinned.

There's no reason to assume that we are currently working with a single independent abiogenesis point on this planet, that is one plausible hypothesis among many and not one I particularly favor.

I am particularly interested in biology, enough to know that the chances of an Earth-adapted microbe or lichen running roughshod over any Mars-adapted life are roughly on the order of the LHC spawning a black hole when it was switched on. Analogies to organisms crossing between the continents and human populations of Earth (which you have not made but several posters have) are incredibly far off the mark. Whatever life has tenuously held to Mars, if it exists, will not be disturbed by our minuscule presence, and it will be sufficiently novel at the biochemical and sequence (will it even have sequences?) level to be readily recognizable, even if it is cultured from the 22nd equivalent of a Starbucks parking lot on Olympus Mons.

The life that we have available to study on earth right now has a common ancestor. There may have been multiple abiogenesis events, but life on earth stemming from other abiogenesis events has either died out, merged so as to be functionally indistinguishable, or has not been discovered. I am unaware of anyone working in biology under other models.

I suspect, as you do, that any Martian life will likely be recognizable as "life". The long term fear is of course that either things from earth will eat all of it, or it will eat everything from earth (that's less of a concern since quarantine in that direction is pretty easy). The short term is what we really need to be concerned about though. In the short term, the concern is that Martian life will be mistaken or written off as life from Earth.

This problem is exacerbated when we consider that the life on Mars that we are looking for could be former Earth life that hitched a ride on some rocks millions or billions of years ago. If we scoop up some Martian soil and find a few rather prokaryote-ish looking things bopping around in it, then exactly what we have just found becomes very hard to determine if our spacecraft was not sterile. Did it just find an example of convergent abiogenesis and evolution? Evidence of panspermia? Or did somebody in the assembly building sneeze on the scoop?

"Quarantine in that direction is pretty easy"

Until unrecognized Martian life jumps onto your happy home-bound spacecraft and starts colonising Earth. We can't even make sure recognised life from Earth is wiped from spacecraft...

I'd prefer the safe approach be taken as well, but I imagine even if there were contamination we would still be able to identify original Martian life by DNA or whatever.

Unless it just gets killed off too quickly.

Before we terraform the planet don't you think it might be interesting to learn about martian history before it cannot be recovered?

If you dig the foundation of a parking lot and you find the vestiges of an ancient civilisation don't you take the time to study what you've found before your send the steamrollers in?

No, you usually just steamroll the dirt.

In the US, yes. But I know Italy and other places in Europe have laws that require an excavation to be done to look for historical stuff. It can end up cancelling entire projects if they discover something important which can't be extracted.

Well Europe has thousands of years of productive civilisation (not to denigrate the achievements of mesoamerican civilisations) - but density and continuous habitation of cities is different in Europe.

It seems madness to suggest we should mount an archological expidition to Mars before a colonisation mission but I hope efforts are made to explore it scientifically.

We have those laws in the US too, and I'm sure Europe has its fair share of developers trying to cover up archeological finds to avoid derailing a development project.

Of course the Avatar example. :-)

I think we will learn MUCH quicker and MUCH more and about the history of Mars once we'll get serious about colonizing it, and not "exploring" it at the the crawling pace it's currently happening at.

Sounds a little like 'We will learn about Martian history as we make it!' although I understand you mean that we will learn about Martian history faster once we get permanent feet on the ground.

Why the hurry? Let's explore it for 100 years before terraforming it. I am not tired of it all, it is much more valuable to figure out what is there first before changing it.

EDIT. Terraforming it in a hurry feels like building a shopping mall on top of the remains of an ancient civilization before it has been properly researched

There is a strong argument to be made that there is a deadline at some point where we will need to have colonized other planets before we extinct ourselves through war.

Though sadly interplanetary warfare seems much easier than extraterrestrial colonization.

Warheads only have to survive re-entry, and they care very little about a prepared landing site.

It would be far cheaper just to build strong bunkers than to build a long-term self-sufficient colony on another planet. Not that a nuclear war would be anywhere near enough to cause extinction in the first place.

I'm all for colonizing other planets because it's cool, but lets not pretend there is any practical reason to do it.

Please, humans destroying themselves through war is nothing compared to a large rock from space hitting the planet at 20,000 miles per hour. The amount of energy in the entire world's nuclear stockpile would be dwarfed by the energy of that happening. Hell, I wouldn't be surprised if the 2004 tsunami in the South Pacific contained more energy than the sum of all of earth's weapons.

The point is if you're going to talk about the threat of extinction, at least provide a plausible case for the argument. The negativity of "humans are going to extinct themselves" isn't inspiring. If we're going to kill ourselves, why even bother? If you want to make a case for us getting off this death trap of a rock, one of "we should work together to fight things out of our control" is much more inspiring than "I want to get off the planet before all you other idiots kill yourselves."

Just if you're interested, it appears it did. 23,000 hiroshima bombs worth of energy:

http://news.nationalgeographic.co.uk/news/2004/12/1227_04122...

From what I can tell that's a lot more than the global supply.

> From what I can tell that's a lot more than the global supply.

Where are you getting that from? Wikipedia says 17,000 nukes (4,100 active), and IIRC modern weapons tend to have ~30x the energy of the one that was dropped on Hiroshima.

http://en.wikipedia.org/wiki/2004_Indian_Ocean_earthquake_an... quotes it as 26 megatons of surface energy, and 9,600 gigatons (or 550 million Hiroshima bomb) of total energy.

Hiroshima was about 15 kT, so your number gives 345 megatons. Tsar Bomba was about 50 Mt, which is more than the energy of the tsunami.

According to http://en.wikipedia.org/wiki/TNT_equivalent , "The total global nuclear arsenal is about 30,000 nuclear warheads with a destructive capacity of 5,000 megatons or 5 gigatons".

The sudden release of Energy isn't what would cause extinction from nuclear weapons, it's the persistent fallout which would make the entire surface of the planet uninhabitable for many years.

http://en.wikipedia.org/wiki/Nuclear_winter

"Based on new work published in 2007 and 2008 by some of the authors of the original studies, several new hypotheses have been put forth.[16][17] A minor nuclear war with each country using 50 Hiroshima-sized atom bombs as airbursts on urban areas could produce climate change unprecedented in recorded human history. A nuclear war between the United States and Russia today could produce nuclear winter, with temperatures plunging below freezing in the summer in major agricultural regions, threatening the food supply for most of the planet. The climatic effects of the smoke from burning cities and industrial areas would last for several years, much longer than previously thought. New climate model simulations, which are said to have the capability of including the entire atmosphere and oceans, show that the smoke would be lofted by solar heating to the upper stratosphere, where it would remain for years. Compared to climate change for the past millennium, even the smallest exchange modeled would plunge the planet into temperatures colder than the Little Ice Age (the period of history between approximately A.D. 1600 and A.D. 1850). This would take effect instantly, and agriculture would be severely threatened. Larger amounts of smoke would produce larger climate changes, and for the 150 teragrams (Tg) case produce a true nuclear winter (1 Tg is 1012 grams), making agriculture impossible for years. In both cases, new climate model simulations show that the effects would last for more than a decade."

>but I think the more important one is when will we expand life on Mars?

Because we've done so well with Earth it's time to take our success to another planet?

Basically, yes.

This is very shortsighted. What is "interesting"? With all the knowledge Alexander Flemming had about bacteria in the 1920's, it was an accident that he discovered penicillin (by contamination from a neighboring lab, while on vacation). Assuming you know the absolute value, or even the best case scenario when it comes to biology is one way to only rely on accidents for important discoveries. Probably not the smartest thing to do.

I think it amusing that the one place where we would most likely find life on Mars, we may be specifically forbidden from going to. Kinda puts a crimp in the 'seek out new life' mission doesn't it :-)

While I have no strong opinion on this, it's interesting from a game theoretical perspective that the only way Mars doesn't get contaminated requires the consent of pretty much all of humanity, as a single entity deciding to send some antarctic lichens (or whatever) can't easily be stopped by the others.

An entity interested in this could be the space program of a country or even a privately backed kickstarter project; such an undertaking doesn't take nearly as much resources as one would initially estimate.

send some antarctic lichens

I know what novel you read - and I recommend the series

https://en.wikipedia.org/wiki/Mars_trilogy

Summary of Mars trilogy: go to Mars, become a hippie.

Ok, I know there's a lot more to the book, but the whole hippie-ish thing blew it for me. I stopped reading halfway through Green Mars when Hiroko shows up naked and the conference for the future of Mars becomes a huge pagan ritual/festival.

If I wasn't interested before, now I definitely want to read this

As I recall, it confused Hiroko as well. Apparently it was translated as an artistic statement against the confines of rigid structure, or something like that.

It's been a while since I read the series. Once it got to the political debates, including on how the future school system might be set up, I started skimming.

My understanding is Mars can never host earth-like life because it doesn't have a magnetic field. There's too much radiation.

If you teleported an earth-like atmosphere to Mars, it would last somewhere in the neighborhood of upper thousands, low millions of years. That would give us a good chunk of time to figure out the whole "create a magnetosphere" problem.

Of course we don't get to just magic an atmosphere out of thin air, but there are a few more realistic proposals.

The fear is pointless in the first place. Life that has been living on mars for millions of years is going to be far more adapted to the climate than anything from Earth.

sigh human memory is so short. It was only a few hundred years ago we last managed to wipe out several advanced civilizations due to inadvertent organic contamination.

While Mars likely doesn't host sentient life, we ought at least show restraint exploring this new frontier until we are able to investigate and prove beyond a reasonable doubt that there is no such life existing in these regions of Mars.

Pft. Which part of "manifest destiny" was unclear about Mars?

>Is anyone else tired of hearing about the dangers of interplanetary contamination

The risk is real - humanity is still learning to deal with it though - people overreacting & under-reacting is inevitable. Damage will be done - such is life. At this stage I think that space exploration as a whole should take priority. Perhaps we screw over a planet. So be it. Mistakes are inevitable & I can deal with that. Space exploration & humanity's long term survival being screwed with by republican vs democrats debates...that is a serious problem for me...and I'm not even an American. Humanity as a whole suffers.

What? Don't you think that any life existing on Mars has the most to teach us about how to successfully live on Mars?

I say we just dump a few tons of various vegetation all over Mars and see what happens :-). There's plenty of space to do archaeological research, it's not like Mars is the size of Machu Picchu or something...

This comment really makes no sense.

We have no idea where we'd start on terraforming or if it's even possible. It'd probably take a century or two just to come up with a tenable plan if we started throwing an unlimited amount of money into it now. And then it would take tens or hundreds of thousands of years.

Terraforming is, at best, a game for those with impossibly long attention spans, not those who become impatient on the time scale of decades.

Why do you want to see mars terraformed? I agree it sounds cool, but what would be the point? if we want more comfort, it would be much much easier to control our population growth and preserve our resources.

I'd be okay with just having a colony there. In the long term, the sun will go boom and we're not going to want to be there when that happens. Of course that's super-mega-long-term, but the only way we'll ever be able to move from Earth is if we start taking small steps in developing what we'll need for that. Creating a colony on one of our closer neighbors seems like a pretty good next step to me. Why not start sooner rather than later? I agree it would be great to fix the problems we have on this planet first, but even with adequate allocation of resources, it might take less time to put humans on Mars than it will to eradicate poverty, end war, and reduce population growth.

Discovering life on another planet would be an incredibly significant historic event. Frankly, it would change everything. It may be the most important first goal as well. I believe that we would find that answering that question would usher in a whole new era of science and exploration.

I think the key part of this research is that this adds significantly to the evidence that there's liquid water deep in the crust of Mars. We know that there is water in the form of ice in lots of places on Mars but the idea of subsurface liquid water is exciting because there might be life in there! If it's gushing up to the surface periodically, we might even be able to sample it and see if there's signs of life! There's been previous evidence of these streaks before - but researchers had generally thought that was due to ice melting during the planet's warm season. Now they've found "streaks near the equator, including in the gargantuan Valles Marineris canyon". Any subsurface ice here would likely have sublimated. So it's looking pretty likely that this is subsurface liquid water that is leaking out from time to time. An alternative explanation - dust avalanches - was offered when the same scientists unveiled their initial results back in 2011. With the observation of so many streaks at the equator now the simplest explanation appears to be groundwater welling up to the surface. Similar streaks on Antarctica are known to be caused by water.

I know this is an unpopular opinion here but:

NASA needs to stop milking the "water on mars" thing. Every few months it seems their PR department lazily says to themselves "Hey! let's do another water on mars story!" (I know, NASA doesn't do PR and these are just completely objective releases of scientific papers... believe what you will.)

I hope within my lifetime we have some disruption in this space and NASA stops constantly taking blatant advantage of its near monopoly on space exploration.

How would a private company "milking" science be any better?

>NASA needs to stop milking the "water on mars" thing.

Perhaps. I'm inclined to cut NASA some slack though - they are in a tricky catch 22 position: To get spectacular results they need funding and to get funding they need spectacular results. So I'm all for them milking whatever seems viable.

>its near monopoly on space exploration.

When it comes to space exploration I tend to agree with Nike & their slogan. I really don't care whether the US or the Chinese does it as long as someone acts. Same thing with costs...humanity as a whole needs to get off this rock to have any hope of long term survival. If it takes X billion USD...who cares? Raise some notional debt ceiling if you must...

> humanity as a whole needs to get off this rock to have any hope of long term survival

Or, people could have <= 2 kids on average. Seems more achievable to me than terraforming another planet.

Agreed. Your answer is entirely sound. We are talking past each other here though.

We are talking about fundamentally different time scales here: I was thinking more asteroid hitting earth / nuclear MAD. Sooner or latter something scary is going to screw over earth. Given sufficient time its inevitable - earth is going to die...maybe tomorrow, maybe in a billion years. If it happens tomorrow...so be it. Nothing can be done about that. If it happens in 200 years & humanity didn't plan for it then I'd say humanity fcked up things in royal style.

Thats also why I don't care whether the US/russians/chinese make progress...they're all humanity in my book.

Terraforming - admittedly not happening right now. Forget terraforming. I just want to see progress. The above risks are real & we don't have an answer right now. Fine - so be it. Republicans & democrats arguing about debt ceilings and NASA budgets...that I have little patience for. As I said - Nike slogan. How exactly progress is achieve - I really don't care as long as it happens. Frankly I'm thankful that the Chinese are playing the space race. Their political structure and resource allocation seems uniquely well suited to said nike slogan approach.

During the Apollo era the US gov had both the political will & the public support. In short - they were invincible & the outcome was certain. If a nation like the US is collectively hell bent on putting a man on the moon...then a man shall walk on the moon. The US has lost that spirit & right now the Chinese are humanities best hope - yes the US has mars ambitions - it'll go nowhere. This I'm certain of - unless something drastic changes. Compare the __ emotional content __ of Kennedy's moon speech vs current NASA budget cuts. Forget budgets, technical ability etc...just emotional content. That is why I'm cheering for the Chinese - they have the will power and the resources. The US has politicians squabbling about budgets.

What extra percentage of taxes are you willing to pay? Assume that the everyone gets the tax hike and the money is well spent solely on this issue.

It is highly uncontroversial that there is water on Mars. NASA does press releases for the discoveries they make in general, the "Mars/water" stories are not really given special treatment by NASA above and beyond their other interesting stories.

The difference is the media and general public, who for some bizarre reason have decided to cling to the idea that there is no water on Mars but NASA is desperately trying to find it. Therefore, whenever NASA talks about water and Mars they all go ape-shit, like when a university announces that a drug one of their researchers is working on that is suppose to slow the growth of one particular type of cancer completes one stage of animal testing.

Complain about the people that are actually the problem here.

I think they put out regular press releases of anything interesting they find. HN just has a taste for certain types of articles is all..

> I hope within my lifetime we have some disruption in this space and NASA stops constantly taking blatant advantage of its near monopoly on space exploration.

I think that with Mangalyaan well on its way to Mars we can probably - barring a mission-crippling accident - say that the disruption is in progress.

Oh how I wish Mars had a thicker atmosphere.

You'll love this!

http://wikitravel.org/en/South_Pole

Rocks, water ice, and a thick atmosphere with oxygen. For only 0.00001% the price of a Mars vacation.

I'm half joking, but I'm worried someone will try to sell spaceplane trips to some inhospitable alien desert like Namibia and market it as "the interplanetary experience"...

edit: Actually that could be interesting..

Ooh, I'll happily build the spaceship's "earth communication unit" so it has realistic delay:

http://stackoverflow.com/questions/614795/simulate-delayed-a...

Death Valley in California is good enough for that IMO.

Why worry? Who cares if somebody wants to fly over Namibia and pretend they're looking at Mars?

Hey, don't give people stupid ideas :-). But really, that could pretty cool (until you find out you were duped).

"Drink

As the Pole is entirely covered by a massive ice sheet, those with the ability to melt ice should not worry about lack of water."

Set up a distillery to make martian whiskey, it would cost a bomb.

Some time and funds: https://en.wikipedia.org/wiki/Terraforming_of_Mars.

I strongly suggest we start a kickstarter.

You've my 10 bucks.

$20 from me if that tier includes a shirt.

you'll enjoy this: http://marscoin.org

So, how legitimate is this claim? I feel like we hear about this all of the time, only to be disappointed later after further analysis.

As far as I can tell, this is not a claim at all. It is an observed phenomenon, for which the presence of water is one possible explanation.

As far as I can see, shadows being the other one. Depending on the time of day / position of the sun of course, so it should be easy enough to rule that one out.

Could it also be explained by saltation[1]? If avalanches can behave like a fluid due to a saltation layer, and saltation can happen to sand particles in wind, then couldn't the streaks be caused by sand/wind instead of water?

Any geologists reading that could offer an opinion? Would this part of the article support this hypothesis:

> Some of the streaks seem to begin at the tops of ridges, too close to the surface to easily be explained by subsurface aquifers

[1] http://en.wikipedia.org/wiki/Saltation_(geology)

It is also possible that there are a number of other explanations that nobody has considered. Ruling out shadows doesn't confirm water.

Why not send a drone plane together with the Curiosity? It sounds more efficient doing exploration from sky than land. I get that the weather could be a problem. Anyway, just food for thought.

Not enough atmosphere to generate lift. Same reason we can't fly satellites into orbit.

Silly question, but why is it that we can't fly a satellite into the orbit of Mars? What is it about the space 300 miles up from Earth that differs from Mars? (unless we also want to discuss geosynchronous orbit)

Edit: I should have written "launch" a satellite into Orbit from Earth to Mars

Actually we currently have 3 satellites orbiting Mars:

http://en.m.wikipedia.org/wiki/Category:Artificial_satellite...

"Same reason we can't fly satellites into orbit [of Earth]"

Orbit isn't about going up - it's about going sideways so fast that the planet curves away just as fast as you fall towards it. While you can use the atmosphere to lift yourself up to a certain extent, it doesn't help you achieve orbit. The 100km boundary for space on Earth isn't picked as just a clean number - it's the altitude at which a plane would have to fly at orbital speeds to generate the required lift, and if you're going orbital speeds you don't need lift.

I know this doesn't exactly answer your question, but it might help to frame it better.

I probably should have phrased it better, actually. I understand the concept that the satellites are falling along a path in orbit that causes them to "miss" the planet as you describe. I misunderstood the parent's phrasing use of flying, which implies the presence of an atmosphere, as opposed to just "putting" a satellite into Mars orbit(by way of launching a rocket with the desired payload or whatever).

The pressure on the surface of Mars (0.6 kilopascals or 0.087 psi) is about one tenth of the pressure at the height of 20KM from surface of Earth (Armstrong limit 6.25 kilopascals or 0.906 psi). Of course, the structure of the "Martian" plane has to be designed accordingly. But definitely not impossible though.

Why not a drone dirigible?

My hypothesis: The minimum atmosphere likely makes it hard for anything to fly close to the surface. Most of our drones/flying machines (winged or rotored) depend on there being relatively thick air to "push" off of.

A drone plane has been considered, although the technical feasibility isn't really there. Mars has less than 1% of the atmospheric pressure that Earth does, so a drone would have to fly very fast to get to proper lift. This comes at a high energy cost, which would be hard to provide in a lightweight package. Additionally, the plane would have to land at night and do so autonomously.

Even if all of this was achieved (and it is by no means impossible), the drone wouldn't really provide more data than the satellites in orbit already do. Aerial survey is pretty much taken care of, what is needed are actual samples of minerals on the ground.

However, if people were able to go to Mars, some sort of drone would be ideal for real-time surveys and control. The explorers would be able to recharge the drone at will so power isn't too much of an issue. There are ideas floating around that talk about a drone that kind of acts like a grasshopper: it takes in Martian atmosphere, and uses it to 'jump' around the surface. It then lands and takes samples, and recharges its energy for the next hop.

I believe that most UAV designs for extra-terrestrial missions are designed around the use of airships rather than more traditional airplane or quadrotor designs. An example of initial research in the area is the Titan Aerobot [1]

[1] https://scienceandtechnology.jpl.nasa.gov/research/facilitie...

You are very right - I forgot to mention those. They tend to be a lot more feasible than fixed-wing aircraft, and their ability to land and take samples makes them even more useful.

Much though I love the idea of extraterrestrial airships, wouldn't an airship be even less effective than heavier-than-air machines in an incredibly thin atmosphere like Mars'?

Airships would be harder to make work on Mars, but once you have it working you would almost certainly be in a better position.

Also, Wolfram Alpha peggs the air pressure at 39km on earth, the height Felix Baumgartner jumped from, as 330 Pa. It has the atmospheric pressure on Mars (presumably the average at the surface) as 650 Pa. So balloons that will float in that, at least at a low altitude, are not beyond our engineering grasp. (and unmanned balloons on earth have gone down to as few as 55 Pa http://en.wikipedia.org/wiki/High-altitude_balloon).

Thanks for the detailed explanation, very informative. Could a big Zeppelin-like airship filled with hydrogen make more sense on Mars?

Yes - so long as the payload was very light. We're talking maybe 35kg here[0].

[0] http://eoss.org/eoss043/EOSS43summary.pdf

The pdf was a fun read. Thanks. Don't know where did you get the figure of 35kg though. The article talked about a payload of 12kg if the balloon is filled with NH3. My estimation is that the payload can be increased to about 60kg if hydrogen is used instead, assuming the Mars does have plenty of water. With a bit of more creativity, that figure can be improved even further.

"if Helium is used instead, assuming the Mars does have plenty of water."

I think you mean hydrogen? Assuming we can make a rover that can collect non-trivial amounts of water (say by baking it out of the dirt), we could make a hydrogen filled balloon with electrolysis.

Thanks. Fixed.

I had at first put the 12kg max from the first figure, but on re-read I saw the water vapor pressure could have a balloon go as heavy as 35kg. It would makes sense that helium (or more preferably hydrogen) would work better. I suppose I should RTFA better next time.

They had a mission to do so, but it was cancelled. http://marsairplane.larc.nasa.gov/

The video of the drop test is pretty neat.