The FREND instrument searches for neutrons to map hydrogen content in the Martian soil.
FREND revealed an area with an unusually large amount of hydrogen in the colossal Valles Marineris canyon system: assuming the hydrogen we see is bound into water molecules, as much as 40% of the near-surface material in this region appears to be water.
How confident are we that hydrogen detected really is water?
There just aren't alternatives to what it could be.
Hydrogen just doesn't get bound up into minerals (unless essentially as water) and not at any great density, and there isn't another plausible substance that would be hanging out in a canyon on mars.
If there was ever life on Mars at scale it wouldn't be impossible or unusual to find oil and coal, would it? Or does it degrade on the timescales that would be required for this to be possible?
tbc I don't believe there's oil on mars nor do I think it is remotely likely.
Evidence points to tectonic activity and liquid water on Mars at one point in its history so theoretically, yes. The geological processes that can move fossils deep enough to become fossil fuels could have been present along with the mud slides and sediment that are most favorable for preserving animal remains.
Earths, yes, but there are hydrocarbons elsewhere that are not biological in origin.
“Methane (CH4) is abundant on the giant planets—Jupiter, Saturn, Uranus and Neptune—where it was the product of chemical processing of primordial solar nebula material. On Earth, though, methane is special. Of the 1,750 parts per billion by volume (ppbv) of methane in Earth’s atmosphere, 90 to 95 percent is biological in origin.”[1]
Life is very likely to be carbon based (what other element makes 4 bonds, as is necessary for 3D structures?). Where life is carbon-based, decaying life in the absence of oxygen produces hydrocarbons.
There is silicon. Some sci-fi authors have postulated silicon-based life in their stories. (It’s been too long, I don’t remember which.) As with most science fiction, how plausible that is, is a different matter altogether.
very possible!!!!
In fact, the ground temperatures at the rover landing sites swing up during the day and down again during the night, varying by up to 113 degrees Celsius (or 235 degrees Fahrenheit) per Mars day.
https://mars.nasa.gov/mer/mission/rover/temperature/
Those temps for the freezing point will be for pressures above the triple point of ammonia, or pressures you’d find on earth.
The pressure on mars is too low for liquid ammonia to exist and the freezing/sublimation temperature is more like 180K or -100C
And to exist underground in large amounts for millions or billions of years it’s not good enough for temperatures to occasionally be low enough to freeze ammonia, when it was warmer the ammonia would turn into gas and blow away so unless there is a significant local source of ammonia it is highly doubtful that is where the hydrogen comes from.
Is water on Mars even exciting? We're already quite certain there is a ton of water on Mars... in the form of ice. The exciting discoveries are evidence of liquid water.
> The bulk of the northern ice cap consists of water ice; it also has a thin seasonal veneer of dry ice, solid carbon dioxide. Each winter the ice cap grows by adding 1.5 to 2 m of dry ice.
> The part of the cap that survives the summer is called the north residual cap and is made of water ice. This water ice is believed to be as much as three kilometers thick.
It is very exciting in the equatorial regions as it was typically assumed that because of the high summer temperatures (~70°F), any ice would melt and the water would evaporate. Valles Marineris would be an excellent location for a human settlement because of these warmer temperatures and the higher atmospheric pressure in the canyon. If there is water there as well then it ticks all the boxes.
But the pressure is still effectively nil. It's far below what would be needed for humans to venture outdoors, and makes a negligible difference to the strength required for pressurised buildings.
Absolutely but every little bit helps. A thicker atmosphere also means less radiation, thus less radiation shielding required. I don't have numbers on hand but from what recall it is a significant enough of a difference to worthy consideration.
Yes and no. Yes because there are people on Earth adapted to living at great heights (the Andes or Himalaya) and no because the pressure on Mars is far too low. At Mars' pressure, the boiling point of water is so low that our body temperature is too high and makes the blood boil.
If we found microscopic life forms in the water though, would we create a settlement or not? It would be so easy to contaminate stuff with a settlement there. I could see people pushing for it becoming a reservation, only to be studied from very far away using hyper-sterilized robots. At least for a while until we are sure we've exhaustively cataloged everything.
Finding life would be huge, we're not going to just go settle on top of it willy-nilly.
Which is what scares me. Yes it s cool to protect the local microbes but damn arent we also an important local life form of the solar system that would leap one level in evolution by just living on two planets ?
Should we lose that for the sake of microbs, as long as we can preserve them for study?
To an extent, it depends on what we find. What kind of biology does it have? How many species are we talking about? Can we throw it in a bio-bank somewhere and move on? Will it outcompete any Earth life we try to seed? Could it be dangerous if it colonized the Earth?
Earth should be as unsuitable for them as mars is for us, except in the case of non alive organisms like viruses or prions. But to have viruses you need higher forms of life supporting them, those based in cells
If we found some alive in Mars and we could found it quickly if we found a cannon with water, we should call them in a distinct way. I will propose marteviruses:
Marte-herpesvirus, Marte-adenovirus, Marte-coronavirus, etc.
Another way could be putting before a M- prefix but would be less convenient to read
One of the interesting consequences of water on Mars is the fact that it can be used to make methane and oxygen (used by both SpaceX's Raptor and Blue Origin's BE-4 engines). This potentially increases the amount of cargo one can carry from Earth to Mars as one no longer needs to bring hydrogen (for the Sabatier process for making methane) from Earth for the return trip back to Earth
Refueling for what? The realities of orbital dynamics mean that Mars isn’t a convenient stopping place on the way to say, the outer solar system. I don’t have the numbers in my head but the delta-v requirements to intercept, match velocity and land negate any potential refueling benefit in my understanding. (Not to mention the added complexity vs a straight shot, this is a lot to pull off even in a sim like KSP)
You might be able to make an argument for refueling bases on Mar’s tiny moons with their negligible gravity wells for Martian missions themselves but that’s about all I can see.
But what if you built a base there that continuously flung refueling pods into orbit? Make these pods leave orbit to rendezvous with another craft somewhere else rather than the craft needing fuel to come to a stop on Mars.
Every deposit of water, even as ice, opens a new series of inquiry. Suddenly you have new regions, geographies, biogeochemical hypotheses, and potential support for life. More history, more to explore.
New sites give us more to consider for future missions and broaden the set of experiments we want to conduct.
I'd much rather keep finding water, even as ice, then have the planet run dry. It only increases the odds.
Though I distinctly remember reading in an encyclopedia from the '70s that certain large dark regions on the Martian surface were believed to be thick vegetation (: I'm not kidding!
From [1]: "As recently as the early 1960s, it still seemed possible to a few astronomers that the dark regions had some kind of plant life because they seemed to darken each summer as if plants were growing in response to sunlight."
Yes, I remember reading books from the 60s my grandmother got from a charity shop. They had wonderful illustrations of Mars with vegetation and where the canyons discussed in the article were canals full of water. It's easy to forget just how much we've discovered about the other planets in the solar system in the last 50 years.
There is so much science fiction writing from the golden age and beyond, up to the 60s and 70s, which prominently features Martians and Martian cities. Mars having alien life was a massive source of speculation among the public at that time. While the stories are still great, reading them today I can't help but go "nah we've been to Mars, there's nothing there".
Makes me think about how soon sci-fi written today will get similarly outdated.
I'm reading Red Mars at the moment, written in the 1990s and set in the 2030s, and a cluttered lab is described as having piles of floppy disks lying around. So, yeah.
It was observed simultaneously as canals and vegetation were "observed", and roundly discarded by 1970s. Water on Mars remained unconfirmed until this century.
One of the more interesting challenges in creating self sustaining colonies on other planets is the availability of water. And this is another example of how Mars might provide water in a very accessible way (40% by volume is a lot of water :-))
NASA has already pretty much convinced itself that plants could grow in suitably amended martian soil[1][2]. I haven't seen a paper yet on whether or not there is enough solar irradiation for robust photo synthesis (needed for the production of plant sugars) but one could always add grow lights powered by one of the small nuclear power sources[3].
The thing I don't understand is why aren't we building something here on Earth that is underground designed to be a self-sustaining system. It seems like if we can't figure out how to do it here, we have no chance to do it on the Moon or Mars. Mars is cool as a story but we don't have our sh!t together enough to really try.
I can tell no one here has any real awareness of the real science literature written on the subject. We are building, testing, and designing things like this all the time. Just in smaller increments. Just last year I met a young scientist who was working on a research base in Antarctica doing various biology studies on plants/animals living in low-light sealed environments... I was headed to the North Pole and she the South.
I know a one-to-one experiment has a grandiose appeal, but NASA and all sorts of other institutions work on this problem in minor steps every day. The step just aren't, on their own, media worthy or very sci-fi-ish. Heck. Antarctic bases and the ISS, and many other science ventures are essentially a testing ground for some of these things on their own.
My apologies if it's condescending, that's not my intent. I wanted to point out that there's a lot of large wild hairs being thrown around, that's all.
It's a good question, the whole "Biosphere" project which you can go visit in Arizona which sought to do something like this. It isn't underground, there really isn't much advantage, and there is a whole lot of expense, in building under ground.
So the partial answer is that people are doing this research. Complex interactive systems like this however are very hard to design all at once. One strategy might be to solve individual problems like having a habitat that provides all of its own oxygen and CO2 processing. Then once that is understood have one that can recycle 100% of bio-waste. Then add a long term power supply, then figure out how to make that supply a renewable one. It is a very complex process and each step will reveal new interconnections that need to be dealt with.
If the Biosphere project taught us anything it's there is a huge amount of problems that wouldn't transfer into other environments, and those other environments will also create tons of different nontransferable problems.
While the famous experiment is over, they've not stopped entirely. Three months ago [0], they announced they'd reopen a small portion of it to investigate how they can winnow down from scrubbers to plant based oxygen replenishment.
You seem to be assuming that a base on Mars or the Moon would have to be a closed system but that is not true.
There are plenty of useful materials on a planetary surface, for example water. There are also many ways to take advantage of a CO2 atmosphere or oxygen from lunar rocks.
Even space stations don't need to be fully closed, for example the ISS is constantly being resupplied.
Because that's boring. Once Mars colonies become a real possibility, obviously the missions will be tested on earth before we yeet billions of dollars to another planet and hope it all works. But going through all that work and money solely for the purpose of an Earth bound terrarium is boring. Who would want to pay for that?
Not only is it a profound and fundamental capability if we intend to live off-planet, it's basically the only relevant capacity, conceived broadly (how to manufacture the means for indefinite survival given supplies of matter and energy). It's the universal constructor problem and our present solutions are fragile and primitive. There is virtually infinite room for improvement. How is that boring?
You’ve got it right here. If life’s ultimate purpose is to grow, we have a whole solar system we can grow into. Once we solve growth on planet two, we will be vastly closer to other planets, moons, asteroids and habitats. There’s a whole lot of energy and materials right here at this star and a whole lot of real estate that doesn’t require an environmental impact statement. Per aspera ad astra.
regardless of questions of growth or ultimate purpose we need to be able to do this if we want to persist for any significant length of time in any habitat, planetary or otherwise
a truly sustainable civilization can successfully manage its planetary (or ship- or station-borne) ecology and protect itself from threats with advanced technology equally well, and we are wildly immature in both capacities
>> obviously the missions will be tested on earth before we yeet billions of dollars to another planet and hope it all works.
That's my whole point. This work is only interesting as a precursor to doing it on another planet. Nobody has any motivation to do the work and spend the money without a direct connection to transferring it to another planet.
Whenever someone says "why don't we just do it on earth first??". We will: but only as the testing phase of an actual mars colony mission.
were we not actively making this planet more difficult to live on I would be a bit more likely to agree but even so there seems to be plenty of motivation
do we not want to be resilient to e.g. solar flares, supervolcanoes, asteroid impacts/nukes/tungsten rods dropped from orbit, on Earth or Mars or anywhere
I think some benefits are difficulty (we want to stress test), similarity (we probably build underground on Mars), and a whole lot fewer outside influences (a lot fewer organisms underground).
Heliostats could work too but might be a challenge with the dust storms. At least at first.
What’s the current wisdom on bioremediation of perchlorates? That seems to be the sticking point.
We know on earth that tidal zones have been a hotbed of evolution. I have this notion in my head of creating terraforming equipment (specifically atmosphere and water) that buffers its output and releases it in pulses though a transitional zone. Like a marine fish tank. Say at the bottom of a canyon or partially enclosed space.
This alternating availability of resources should select for more resilient lines.
Every 5 or 6 years since I was born, NASA has discovered water on Mars. I was predicting they would discover water on Mars back in 2020, but I think COVID clearly slowed them down this time.
No, and Valles Marineris is about 7km deep in places vs the Grand Canyon's 1.8km max depth, not something a rover could go check out.
Robert Zubrin actually uses Valles Marineris as part of the plot in his work of fiction First Landing that lays out how a manned mission to Mars might go.
So, we ship our carbon to Mars, which warms it up while solving our climate problem. Once it's warm enough, that water can exist on the surface, setting it up for terraforming.
Now that I've solved all that, I think I'll knock off early for the weekend.
Not enough carbon, that said somehow siphoning CO2 from Venus turning it into dry ice and using a mass driver to shoot it at mars whilst completely nuts and well beyond our technological reach might actually work.
It would also be a 2 for 1 terraforming effort. Then the only thing you need to do is figure out how to spin Venus to break the tidal lock. And if you set up your mass drivers correctly you should be able to give it some additional spin at least.
I don’t understand any of these comments. Discover has two meanings. Unexpected or within the course of a search. We discover oil and mineral deposits all the time. We don’t usually say “You discovered more lithium? Big deal. Been done before”
While it may not be mind blowing, each source of water discovered makes some kind of Martian base more feasible so it is of interest to some
If new sources of water don’t interest you, that’s fine. But it is still within the definition of discovery
Question is when will someone invest in a mission for something that actually does something with it that is not measuring its existence with remote sensors.
FREND revealed an area with an unusually large amount of hydrogen in the colossal Valles Marineris canyon system: assuming the hydrogen we see is bound into water molecules, as much as 40% of the near-surface material in this region appears to be water.
How confident are we that hydrogen detected really is water?