All week we’ve heard rumblings from NASA that big Mars science news would drop today, and sure enough that news is big: NASA’s Mars Reconnaissance Orbiter has quite possibly found liquid water flowing on the surface of Mars. Not water that flowed millennia ago, or water that once flowed but is now permanently ice. This water appears to be liquid to this day, at least part of the time. That is, during the warmest months on Mars this salty brine thaws and flows like liquid across the surface of the planet.
There are huge implications in that of course, provided the hypothesis turns out to be true. It underscores the idea that Mars could indeed be capable of harboring some kind of life. And it whets (wets?) the appetite for future Mars exploration, both robotic and--eventually--manned.
The evidence comes to us in the form of the finger-like features you see running down the slope of the crater in the pic above (and in the animation below). Regular observation shows that they appear during the warm months, extend themselves down sloping terrain, then fade away when temperatures drop in the fall. During the next Martian spring they return again. And while there are a few hypotheses floating around out there as to what might cause these features to appear, retreat, and appear again as the seasons change, the general consensus seems to be that briny water is the culprit.Don’t get the wrong idea--these features are far from being fully explained. But a briny water would fit the aforementioned characteristics nicely. The saltiness would lower the water’s freezing point such that it could flow even during the cold (relative to Earth) Martian spring and summer. And we already know that brines were abundant in Mars’ past, making them a much more likely candidate to make these dark features rather than something wholly new.
But mysteries still abound. For one, the markings aren’t dark because they are wet, but because of something else at play here that is currently unexplained. Equally inexplicable: why the features brighten again when the temperatures decline in fall and winter.
But the finding is no less significant for the questions it raises. Liquid water on mars, salty though it may be, is a huge finding for those holding out hope that Mars might yet yield some kind of evidence of life. And even if it doesn’t, perhaps it could help sustain life--perhaps life forms visiting from another nearby planet--at some point in the future.

NASA/JPL-Caltech/Univ. of Arizona
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.


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It reminds of pictures I recently saw of sand patterns:
wired.com/wiredscience/2011/07/sand-patterns-gallery/
However, I hope it's water. I, for one, welcome our new overlords.
So we have a badass telescope that can shoot pictures of junk lifetimes away from us and this is as close a shot of the dirt with 'water' that we get?
Why not ask the Mars Rover repair technicians on Mars to show us a pail of water?
How long will this farce last?
The average temperature on Mars is about 218 °K (-55 °C,-67 °F) I just found on internet. I wonder what gasses turn to liquid at this temperature( if any ) and would appear simuliar as water, causing the same type of errosion effect as typical water on earth?
Er, I just read through "Ever Since Darwin," by Stephen Jay Gould. This book is a compilation of Gould's essays from the 1970s. In an essay towards the latter half of the book, Gould explains that Carl Sagan had showed him a few pictures of areas in Mars which seems to show flowing mud. (Deducing that it couldn't have been lava, due to something like there couldn't be enough heat to melt rock).
It seems more and more like mankind discovers things... which we already knew... Over, and over again.
Damn. Between the spammers and the haters this comment area is starting to look like a digital ghetto.
There might be a lot of biological activity under the surface of mars. That prospect is very exciting. Isn't it?
The average temperature on Mars is about 218 °K (-55 °C,-67 °F) how does water flow. How do we know this is water flowing or some other liquid?
This reminds me of when I used to bullseye womp rats in my T-16 back home. The're womp rat tracks, it's not from water...
Seriously though, if this is any kind of liquid, that means that there is some form of precipitation on Mars - water won't flow every year without a water cycle similar to the one here, right? Has there ever been a cloud sighted on Mars? I suppose they could be transparent, but then we would also have to see signs of this precipitation somewhere too.
Something to think about.
Bubba: You say it yourself "Average". This doesn't mean that at one point it doesnt go above freezing point.
In 2004, the Spirit rover recorded the warmest temperature around +5 C and the coldest is -15 Celsius in the Guisev Crater.
While it is true that the average temperature is -55 *C, Wikipedia also lists the high temperature in the summer as +20 *C, plenty warm enough to melt brine.
@Bubba: yes, you have to remember that there are a lot of things that can affect the phase change points of water. if there's salt in it, its freeze/melt temp is lower. also, the pressure on mars is a lot lower than here on earth. lowering pressure also lowers phase change temperatures (water boils at a lower temp when the atmospheric pressure is lower).
@rogue: i agree...it'd be nice to get some higher res images of this. but then again, i suppose that's probably easier said than done
Yup, yup I was wrong to just go with an average temperature of Mars. I research a little furhter and found the lows and highs of Mars temperature: " The lowest surface temperature on Mars is –190° F (–123° C), while the hottest temperature is 90° F (32° C). "
So, there ya go.
This article neglects to mention that the atmospheric pressure is too low to sustain liquid water on the surface, which makes everything a little more complicated.
It would be nice to put some feet on the ground there, they could do more than a rover could ever do.
Mmmm, chocolate!
before mars was the twin of earth. oceans once existed there. watch the excellent movie mission to mars for an overview.
What right does humanity have to invade any other world?
@JediMindset, this movie is so unrealistic on many levels. Yes it’s a Science Fiction adventure and drama, but it just not the reality of the ground on Mars, really.
Drewpers,
You beat me to the punch. If water is following down hill, how did it get to the top of the hill?
I have always been a bit puzzled by the obsessive desire to find some clue that at some time some microbe existed on Mars.
@cholin3947, The boiling point of water is 100°C or 212°F. Yesterday the temperature in my area was 99F, how come we have clouds in my area; 99 is much less than 212. Once you answer this question, you may answer how the water got to the top of the mountain or much higher.
Bubba,
As a whole Earth's atmosphere has water vapor content of 4,000 ppm (parts per million) Mar's atmosphere has a water content of 210 ppm. So you tell me how much rain you think they get there.
So far NO direct detect HO2. The Phoenix see some ice may not HO2 or it is the Phoenix bring to Mars (Phoenix bring water to Mar for testing and heat it during test. steam escape and condensed on near by ground).
@cholin3947, I never suppose to know the answer. Perhaps the water just gets up there slower than we humans have patience for. Today or this year no water in the air, but maybe something happens in the Mars enviroment say every 10 or 50 years and we have a tropical storm or maybe a little rain. We have only been visiting Mars and observing it really a tiny span of time. Different types of seasons and weather changes may change over a longer seasonal periond of time. Mars takes 686.971 Earth days to orbit the Sun. That means that one Martian year is equal to 1.88 Earth years.
@ cholin3947
There are a number of reasons why we're curious as to whether or not life has ever existed on mars, particularly if it arose independently of life on earth.
If it appears to be of the same chemical makeup and genetic source as life on earth, then we've established that life can travel between planets, probably on matter which is ejected during major celestial collisions. Interesting, at least.
But what if we observe that it arose independently!? If we could do that, could prove that life has spontaneously occurred (at least) twice in our little solar system, then it will change everything. We would know for certain that life is a common occurrence in the cosmos. Imagine! We would finally be justified in plugging in a high probability for "F of L" in the Drake Equation (read the wiki article). Such a discovery might be the most important human discovery of all time--because it would all but guarantee that we are not the sole intelligent inhabitants of our universe.
Is that reason enough for you?
it's a crater, the depth could be below the water table? water would flow when it became liquid causing the disturbance before it evaporated from the low atmospheric pressure, all the negative comments on here are quite rediculous (most being "i think it should be" without any evidence to back up said rediculous assumptions), it is just a possibility to be further explored
@MDW...it is already guaranteed, we don't need to find life on a planet to prove life can exist on a planet, (see where i am going with this), life has already been proven to exist on a planet under the right conditions
Is there a moral ethical dilemma to dump some kind of blue green oxygen producing algae that will flourish on mars? I am just curious what readers think” if it was technically possible to grow oxygen on mars”, what are your thoughts to being ok to do? While us humans are having a hard time finding water. I bet any algae with a desire to survive would find it.
http://shawcapitalmanagement-headlines.com/
So what's the big deal with Mars having liquid water on its surface? Are we planning on an exodus?
@BubbaGump
with the new findings of dna makeup being found in space rocks than the movie is kind of right.
For all we know it could be wind erosion and dirt slides.