On The (Salt) Waters Of Mars

Monday morning the world was greeted by an announcement from NASA that (after much deliberation and careful examination of all their scientific data) the presence of liquid water on Mars has been confirmed.

I repeat: there is water on Mars.

Well, we kind of already knew this as NASA has been giving us hints in the form of pictures suggesting that Mars has water, mostly in ice form. There were also tantalizing pictures over the last 40+ years to suggest that water routinely flowed on the surface, as evidenced as far back as 1971 by Mariner 9 and you’d think with all that evidence staring us in the face NASA would have made this call a lot sooner than they did.

So why wait until now to call it? Scientists are a cautious lot. There could be any number of logical explanations as to why it appears there is liquid water on Mars. In the first place, it might not even be water – could be something liquid, certainly, but maybe not water.

Consider Saturn’s moon, Titan. Recent pictures from the Huygens clearly show what looks like lakes on its surface – but it can’t be water for a multitude of reasons, the least of which being Titan is a very cold place with surface temperatures dipping down to around -220 F.

Better put on your mittens.

In truth, the lakes of Titan are 75% ethane, 10% methane, 7% propane with smaller amounts of butane, hydrogen cyanide, nitrogen and argon – all the ingredients you need to make hydrocarbon fuels.

I personally know a few Texas oilmen who would, on principle, try to recover as much of that as they could.

I remember once watching a documentary on PBS back in the late 70s where one of the scientists being interviewed opined that if we were to send any kind of a spaceship to Titan it would most likely have to be a submarine as it was theorized that the surface of Titan may predominantly be a vast hydrocarbon ocean.

Without the benefit of having seen the surface of Titan (it’s perpetually shrouded in an orange haze that makes spotting ground features impossible) he was nearly correct in his hypothesis when confirmation of the presence of liquid hydrocarbons by Huygens came in 2005, some 25+ years later.

Not a bad guess, really. The only reason this scientist even speculated about Titan is that while we couldn’t see it’s surface feature we could infer what it must be like on Titan’s surface from the composition of the atmosphere going as far back as 1944 by observations made from Gerard Kuiper (yeah, that Kuiper – as in the the name of the scientist for whom the famous Kupier Belt in our solar system is named for) and only because he had picked up on earlier work from a Catalan scientist named Josep Sola whose own work on Titan predates Kuiper’s by 41 years.

So as far back as 1944, at least, the hydrocarbon oceans of Titan have garnered much speculation and hypothesis until we actually went there to look for ourselves.

And that’s pretty much the reason why, even after all the pictures from 1971 forward of Mars that heavily suggested the presence of water, it took so long for the scientific community to come out and say it.

Scientists are a cautious lot, as it bears repeating. They don’t like being wrong (nobody does) and they only pronounce findings after all the data has been carefully pored over – a process that sometimes takes years or even decades.

Science – avoiding the term “slow” – is deliberate. And that’s really a good thing.

Now about this discovery…

It’s amazing to me that liquid water could exist on the surface of Mars at all considering what I understand about it.

Mars’ atmospheric pressure is less than 1% of the total atmospheric pressure of planet Earth (14psi).

While 14 pounds per square inch doesn’t sound like a lot, it matters a great deal as this is the only thing on this planet that keeps liquid in a liquid state, from water in the ocean to the blood in your veins and without it life would come to an end.

On Earth, water boils at 212 F because of our atmospheric pressure. As the pressure drops, that boiling point also drops along with it until you get atmospheric pressure so low that water would actually boil at room temperature (at 0.5 psi, water boils at 79 F).

The atmospheric pressure on Mars is 0.087 psi. At this pressure, water boils at 50 F.

So why doesn’t this surface water on Mars boil away?

Well, it does albeit a bit slower. The water on the surface of Mars isn’t exactly water – it’s more a incredibly salty brine, about as salty as the Dead Sea and just as lethal to a person if you decided to top off a glass of the stuff and drink it.

One gulp would most likely kill you, just like the Dead Sea.

Also, the water on Mars only comes out as liquid during the summer when it’s warm enough on the surface for it appear and, by the way, summer is 6 months long on Mars because a Martian year is two of our own.

The water is coming from…well, somewhere – most likely underground but in a frozen state and what water ice is near enough to the surface will melt when the temperature rises.

Recent photos sent back from the Phoenix lander on Mars in 2008 clearly show water ice at shallow depths that melted then evaporated just about as quickly as it was uncovered so (at least in some areas of Mars) you don’t have to dig very far to find ice.

As for the possibility of life…

Well, the odds of life on Mars are certainly better than they were prior to the discovery of liquid water on Mars as the general scientific community seems to agree on and maybe, just maybe, we will find a niche on Mars suitable to sustain Martian microbes.

The prevailing theory goes that there must be – between the cold ice below and the hostile surface above – a “Goldilocks Zone” where microbial and bacterial life could live and thrive.

I’m of the contrary position that this is probably unlikely, not dismissing the notion completely out of hand but I think if there is such a zone on Mars favorable to life we’re really going to have to go looking for it as it is likely rare such zones could exist on a planet where everything about it is hostile to life as we know and understand it, including the very soil of Mars which will have a go at killing you.

But there have been examples here on Earth where life has taken hold in the most unlikeliest of places from volcanic vents at the bottom of the Atlantic ocean where creatures – instead of living on sunlight and oxygen – thrive on heat and toxic chemicals to the Antarctic where it’s much too cold for us (or for most species on this planet) to survive but doesn’t seem to bother the denizens as they’ve gotten on just fine for unrecorded millennia and because of this I could very well be proven wrong.

I’m also not the only person taking a contrary position of the possibility of life on Mars as there are those in the scientific community who also feel the way I do about Mars and it’s precarious environment.

Because that’s what science and scientists do.

Well, any scientist worth their salt.