By now you’ve heard that Phoenix found ice on Mars. This is cool — har har — but we need to be careful here. Basically, Phoenix scooped up some of the Martian regolith (what most people call soil), revealing some white solid beneath. Was it salt, or ice? A picture taken a little while later showed that some of the white stuff had disappeared.
Sounds like ice to me! Better yet, the temperatures on Mars at that location preclude it being dry ice (frozen carbon dioxide), meaning it must be water ice.
Yay! That’s what the scientists in charge of Phoenix were hoping for.
But while I was at TAM a lot of folks were asking me about it, and it became clear that some of them thought that this was the first time ice had been seen on Mars. But that’s not the case: we’ve known about the polar ice caps on Mars for centuries! The southern cap has lots of both water and CO2 as a permanent feature, while the northern cap is mostly water ice with a temporary cap of dry ice frost that appears in the winter and sublimates away in the summer. That’s why Phoenix went north; we knew before the mission started that there was water ice there!
Don’t get me wrong; this is a tremendous development and very exciting to the mission. it just wasn’t the first time we’ve seen water ice on Mars.
June 24th, 2008 at 4:36 pm
What’s neat about it probably is not a headline-maker for the general population, but from a planetary scientist’s point-of-view it surely is: there is abundant, accessible water ice just beneath the Martian regolith!
One of the major implications from an astrobiology point-of-view is that there may be water underground, where it may remain in liquid form. Whether this is happening now, or happened sometime in the past, means a great deal for the potential of finding evidence for (either extant or extinct) microbial life on Mars. I’m excited about that, but you are correct to point out that solid H2O on Mars has been observed for quite some time.
June 24th, 2008 at 4:46 pm
Of course, we won’t know the important stuff for a little while longer:
Does the water or immediately surrounding soil contain any remnants or building blocks of life?
Did it support any biological processes in the past?
Is it suitable for beer production?
Cheers to the dedicated folks that put the Phoenix mission together! Keep up the great mission, and thanks BA for keeping us informed.
June 24th, 2008 at 5:08 pm
Hmmm, BA you came across there like you think these findings are a waste of money.
I too am interested in beer making potential on Mars, as far as I’m concerned this should be humanity’s number one priority.
And the next mission should search for pizza!
June 24th, 2008 at 5:17 pm
Answers in Genesis already has a guess as to why its there:
http://www.answersingenesis.org/articles/2008/06/23/more-ice-on-mars
“The ice on Mars may possibly be, in part, a frozen remnant of a global Mars flood, which has been theorized by some creationists to have occurred near the same time as Noah’s flood—perhaps even as an extension of it.”
June 24th, 2008 at 5:19 pm
The most important aspect of the Phoenix finding - from a science-philosophical point of view - is that the ice was found, by digging in an apparent dusty desert, precisely where it had been predicted (i.e. some 5 cm deep) based data taken years ago from orbit and with novel methods.
This is science at its best, actually working as straightforward as the layman thinks: discovery, theorizing, prediction, checking it in situ, bingo. Please use this shining example in dealings with the “woo” crowd or how you like to call ‘em …
June 24th, 2008 at 5:30 pm
Water on Mars!
June 24th, 2008 at 5:42 pm
Hey, if they do discover evidence of bacterial life, wouldn’t that mean it’s soil and not regolith?
Prediction: If we do confirm the existence of life near the Mars polar ice caps, it will take Al Gore 20ms to start making alarmist comments about the possible environmental impact of the Phoenix lander’s batteries, and 50ms for GreenPeace to start making protest signs depicting green antennaed polar bears lying face down dead at the foot of Olympus Mons.
June 24th, 2008 at 5:51 pm
You gave a GREAT talk in St. Louis! (AAS)
Did we go to the moon? You bet we did! I mean I was in Houston during 17 and don’t tell me that was not real.
I loved your remarks about parallel shadows in moon photos. So on the mark!
Keep up the good work!
Cheers,
Dick Henry, http://pha.jhu.edu/rch.html
June 24th, 2008 at 6:45 pm
The discovery by Phoenix is exciting because we finally will get a look at water on Mars up close and … OK, not personal, but still …
June 24th, 2008 at 7:05 pm
HWDA, I thought that Answers site had to be a joke or parody site but its for real!!! Yikes can I move to Mars please, it will be safer I think.
June 24th, 2008 at 7:20 pm
@ Kyle, I don’t blame you, ever hear of Poe’s Law.
@Blog re:Post
I like water, it helps a lot when I have to pee. While I understand that the Phoenix lander was looking for life, my mind always wanders off to the possibilities of terraforming Mars, as well as the question of if we should.
June 24th, 2008 at 7:32 pm
If we’ve known that there’s water ice in mars, why do people keep saying there’s no liquid water there? Isn’t it inevitable that if there’s solid H20 at the poles, there HAS to be some place further south where it is liquid? What am I missing here?
June 24th, 2008 at 7:50 pm
Pleco: Yeesh, I had to go to AiG myself for the first time to see that. I thought, surely this is a joke. But no.
Mus: The problem is that water on Mars tends to go straight from ice to vapor, due to the low atmospheric pressure. Liquid water would (almost?) have to be underground.
June 24th, 2008 at 7:52 pm
Mus,
Even at the equator, temperatures at the surface of the the planet seem much too low for water to exist in liquid form. A more promising location for liquid water might be way, way down far below the surface. Any heat generated from deep within the planet would be partially trapped by large amounts of insulating ice above.
June 24th, 2008 at 8:05 pm
Good question.
Apparently not:
June 24th, 2008 at 8:39 pm
Yeah, it may not be the first time we’ve detected ice on Mars, but it is the first time we’ve dug a hole and found ice in it. That’s pretty impressive.
P.S. Now, is there edible life on Mars. That’s the question I want answered.
June 24th, 2008 at 8:49 pm
Kaleberg asked:
P.S. Now, is there edible life on Mars. That’s the question I want answered.
Obvious candy bar references excepted . . .
June 24th, 2008 at 8:59 pm
Has anyone considered it wasn’t ice? Maybe it was white shelled little Martian bugs? Between photos they just dawdled off … or maybe flew off? Where’s Richard Hoagland? This could be some good stuff!
June 24th, 2008 at 9:05 pm
I the reason that there is no liquid water is that the combination of pressure and temp cause water to go from the solid state to the gaseous state and skip the liquid.
Terraforming would be fine by me, but I’m not sure how you handle the radiation since Mars has no magnetic field to protect you.
June 24th, 2008 at 9:05 pm
http://www.nasa.gov/mission_pages/phoenix/news/phoenix-20080620.html
I’m just so surprised that they have to use deductive reasoning to determine the presence of water ice. I would have thought that with all the high-tech gadgetry onboard the spacecraft this determination would have been a slam-dunk. A good gas chromatography experiment would be able to detect it and there must be a hundred other ways to do it - anything from measuring the dielectric constant to having a heated pole touch it.
I don’t know, I just can’t get all that excited about this mission when it takes them 30 days 3 hours 9 minutes 5 seconds into the mission before they discover water ice on the planet when earth-bound astronomers have known it existed for decades. Is there anything on that bucket-of-bolts that wasn’t on Viking 1 and Viking 2? It seems like TEGA isn’t any more sophisticated than what NASA had on the Vikings. It has something like 8 ovens and when each has been used only one time that’s the end of the experiment.
June 24th, 2008 at 9:06 pm
Sorry, my last post should have started “I thought the reason…”
June 24th, 2008 at 9:15 pm
You’re missing the phase diagram of H2O:
http://www.lsbu.ac.uk/water/phase.html
Below an atmospheric pressure of 1000 pascals H20 can never occur in liquid form. The atmospheric pressure at the surface of Mars is only 600 pascals so frozen H2O sublimates directly into water vapor.
June 24th, 2008 at 9:32 pm
Nemo, Brian, RL, and Tom- Thanks! that makes sense. I didn’t know the atmospheric pressure was that low on mars.
June 24th, 2008 at 11:09 pm
This just proves how silly people are, there’s NO pizzas on Mars.
There is however great chances of finding the general ingredients, why else would the Phoenix have eight ovens?
June 25th, 2008 at 12:04 am
@ RL,
i’m not sure, but I think an atmosphere would block a lot of radiation, especially if it happens to have an ozone layer.
According to the BA in his review of The Core,
That’s my source anyway. Other than that, maybe we’ll need to keep an eye on solar weather and shield our devices better. I’m just not sure it’s possible to make enough air on Mars to serve this purpose, and I’m also curious about the need for phosphorus if plant life is to flourish. From what I can tell, Mars lacks an abundance of phosphorus, but I’m not sure if that’s true.
June 25th, 2008 at 12:22 am
First picture from NASA of water on Mars, outstanding!!
http://apod.nasa.gov/apod/image/0504/WaterOnMars2_gcc.jpg
June 25th, 2008 at 2:39 am
And yet, no fog machines and laser lights to accompany Floyd music. Not impressed.
*sarcasm tag, for the sarcasm-impaired*
June 25th, 2008 at 2:47 am
Hey, BA, now you just need to mix the perfect gin & tonic using Martian icecubes…
—
There needs to be a corollary to Poe’s Law that says it won’t be long before a fundagelical site devolves into self-parody…
June 25th, 2008 at 2:48 am
It’s really awesome but I am trying to find a clear answer to a question somewhere but am having trouble? Can someone tell me why it has to be liquid water and not a liquid of something else? I have often wondered if the patterns in the ground that are attributed to flowing water might not be another type of liquid flowing. Also the ice they found with Phoenix and suggest is water ice, how possible is it that it ice of another substance ?
If anyone could explain it clearly, why it has to be water, I’d really like to know ;p
June 25th, 2008 at 3:59 am
quasidog, what other substance would you suggest? This is a serious question. Whatever it is has to have the observed properties: solid at Mars daytime temperature but with a vapor pressure at that temperature high enough to sublime at Mars’ surface pressure of 700-900 Pa. The temperature at the Phoenix site ranges between 196K at night and 256K during the day. At Mars’ pressure, ammonia sublimes around 181K, so that can’t be it. CO2 sublimes at 195K, so it would go much more quickly. Same for SO2 which melts at 200K. Methane is right out. It boils at 112K at 1 atm, so it’d be even lower on Mars. Ethane melts at 90K. Propane, 85.5. Butane, 135. Carbon monoxide boils at 85K at 1atm, again less on Mars. Formaldehyde melts at 156K. All the usual gases (He, Ne, Kr, H2, O2, N2, Ar) would be much too cold in solid form.
Can you think of anything else? Remember, you’d expect to find it in Mars’ atmosphere in at least trace amounts, and I’ve covered nearly all of them above.
June 25th, 2008 at 4:57 am
Tom Marking
It seems like TEGA isn’t any more sophisticated than what NASA had on the Vikings.
If you poke around on the Phoenix site that you linked you will find a mission overview and, as I recall, a fairly detailed press pack. I haven’t had time to follow up and understand the detailed science objectives of Phoenix, but I’m pretty sure it’s a lot more sophisticated than Viking (like both you and Phil Plait, I’m having trouble getting my head round the hoopla about ice, and want to understand what the next step is supposed to tell us).
One of the big problems with landers like Phoenix is that you can’t land, take a look around, and then decide what experiment you’d like to do. You can only do the experiments you take along. (This is one of the main arguments for a sample return mission, though the cost is frightening.) Inevitably that’s going to seem limited and lacking foresight at some point.
June 25th, 2008 at 5:35 am
Of course there’s beer on Mars:
http://www.youtube.com/watch?v=WP6gbxskEuw
June 25th, 2008 at 5:40 am
Thanks for clearing this up, BA. I think the media (both mainstream and other blogs) is part of the problem on this one. Articles I’d read in a few places made it sound like (though didn’t directly claim) scientists weren’t sure if there was ice on Mars. This confused me mightily.
Also, to address quasidog, there have been several observations (I believe infrared and radio waves) in the past several decades that conclusively show it is good old H2O:
http://www.daviddarling.info/encyclopedia/M/Marspoles.html
Although if you’re talking about what Phoenix is scraping against, Phil’s answer about sublimation is more sophisticated than anything I can offer.
June 25th, 2008 at 7:07 am
Hmm… Aliens drink ice water?
June 25th, 2008 at 7:45 am
I haven’t been keeping up with this because while I understand water is important, it’s aliens that are cool.
Anyway, the story I read stated they inferred there is water because small particles that might be ice were there and then they weren’t. Therefore it is ice that melted.
Maybe I’m missing something but that seems like incredibly weak “proof.”
What’s to say they weren’t little chunks of rock that blew away?
Am I missing something?
June 25th, 2008 at 7:51 am
Hooray! We’re talking about Astronomy again!!!
June 25th, 2008 at 8:27 am
“I’m just so surprised that they have to use deductive reasoning to determine the presence of water ice. I would have thought that with all the high-tech gadgetry onboard the spacecraft this determination would have been a slam-dunk. A good gas chromatography experiment would be able to detect it and there must be a hundred other ways to do it - anything from measuring the dielectric constant to having a heated pole touch it.”
You probably could, but this was a serendipitous discovery. The chunks were found when digging a trench. The trench was dug to test the composition of the soil. Unfortunately, there was a problem with the oven used for that purpose. Had it worked as planned, ice would have been found in that sample.
It was only the difficulties with that unit that required deductive reasoning in the first place.
June 25th, 2008 at 9:07 am
Did you say Mice on Mars?
http://www.stevethecat.com/mars.htm
June 25th, 2008 at 10:00 am
“One of the big problems with landers like Phoenix is that you can’t land, take a look around, and then decide what experiment you’d like to do. You can only do the experiments you take along. (This is one of the main arguments for a sample return mission, though the cost is frightening.) Inevitably that’s going to seem limited and lacking foresight at some point.”
Not only that, but the systems checks and maneuvers take for-ev-er because you do NOT want to make a mistake when the craft is so far away. They have to look around, stretch things out, take their time… and yet the scientists and engineers themselves hardly have time for sleep because they are so busy with these tasks.
I only know this from a colloquium that Steve Squyres gave here about a year ago.
June 25th, 2008 at 10:18 am
Well, true, we saw ice before but that was also deduced ice. But from the perspective of the armchair scientist there was still that doubt. We’d been told for a long time that the caps were dry ice. Then that they were a mix of frozen water and dry ice. We read the articles about slump tests done from orbit and how the caps had to have so much of this and so much of that in order to keep from collapsing. We saw the erosion in the craters. We read about the minerals that only form in the presence of water.
We knew, but we didn’t KNOW. That’s what the droid was for.
So now the droid has dug a trench and watched ice sublimate. We’re almost completely sold. We’re 99.44% convinced. What else could it be? But I still want to a scoop shoved in the oven. I want a spectral analysis of the white stuff. That’s when we KNOW it’s water.
June 25th, 2008 at 10:30 am
overstroming said:
> Hmmm, BA you came across there like you think these findings are a waste of money.
No he doesn’t (not to me). What he sounds is concerned that these findings are being misrepresented and overhyped. “We found water ice on Mars.” Uh, we knew it was there. We just got pictures of it up close.
Tom Marking said:
> I’m just so surprised that they have to use deductive reasoning to determine the presence of water ice. I would have thought that with all the high-tech gadgetry onboard the spacecraft this determination would have been a slam-dunk.
I don’t think it’s a matter of being forced to use deductive reasoning, I think it’s a matter of serendipitous images showing evidence of water ice before the experiments are conducted.
> I don’t know, I just can’t get all that excited about this mission when it takes them 30 days 3 hours 9 minutes 5 seconds into the mission before they discover water ice on the planet when earth-bound astronomers have known it existed for decades.
Pre-programmed algorithms updated from afar and transmitted via radio to tell the arm where to go and sample, checking out the systems prior to using them, looking around with the cameras prior to digging - all sorts of reasons why things take time. You’re not happy because Phoenix isn’t like walking out the hatch, grabbing a shovel, and scooping up a pile of the first spot you see. Great. That’s why we need human explorers on Mars. For robotics, you get a slightly slower pace.
> Is there anything on that bucket-of-bolts that wasn’t on Viking 1 and Viking 2? It seems like TEGA isn’t any more sophisticated than what NASA had on the Vikings.
I’m not certain what Viking had vs. what Phoenix has. However, unexpected hardware difficulties with the oven doors is contributing to the delay, as well as data transfer problems.
>It has something like 8 ovens and when each has been used only one time that’s the end of the experiment.
That was curious to me as well, but there are practical concerns. First, the intent is to have 8 separate, independent samples. The problem is there is no easy way to clean an oven once it has been used in order to make sure the second use is not contaminated from the first use. Ergo, separate ovens. Then add in that given the location at the pole the lander will likely not survive the Martian winter and it makes sense to have a limited number of one-time-use ovens that provide independent sample analysis, which also gives redundancy. If oven doors on 1-3 and 6-8 work properly, then the glitches in doors 4 and 5 won’t be so bad a loss. Of course since we don’t know why 4 and 5 aren’t working, that suggests we may have troubles with the others as well. That does not bode well.
quasidog said:
>I have often wondered if the patterns in the ground that are attributed to flowing water might not be another type of liquid flowing.
My dad had that same question. I finally got the opportunity to ask Steven Squyres that question. His answer was given the conditions on Mars and the observed patterns, it is difficult to see how it could be anything else. Wind couldn’t create the patterns demonstrated, it would have to be something a lot more dense. Whatever it was, where did it all go? The thought is that water might be trapped below the Martian surface, but also some of it got stripped away into space with the atmosphere.
CafeenMan said:
> What’s to say they weren’t little chunks of rock that blew away?
> Am I missing something?
First, the atmosphere on Mars is very thin, so the wind is very weak. Even a fast wind is weak. Second, there are no indications in the pictures of tracks or wind effects. There are no marks of a rock rolling across dirt, no loose dust. No data indicating being hit by a dust devil. What you see is lumps there and then not there. The white stuff that is exposed has a reduced visibility, as if exposed ice has sublimated and the dirt around it is left behind.
June 25th, 2008 at 10:56 am
BA said: “Ice is nice”
Which leads to the rhetorical question, “How does it feel to be frozen?”
Then RL said: “… to go from the solid state to the gaseous state and skip the liquid.”
Which should be followed by something like, “Now if I can just keep it from exploding.” (then he puts on a pair of goggles)
If you’re confused then you’ve never seen (or aren’t thinking about) “Real Genius”.
On an unrelated topic: I’ve been watching “Firefly” for the past couple of nights. You’re right, BA, it’s awesome.
June 25th, 2008 at 1:42 pm
Remember, the planned operational lifetime of the lander is only 90 Martian sols (about 92 days). One third of the planned mission is already over and they have just deduced the presence of water ice - not directly measured it. Also, I can’t help but notice the almost total lack of AI (artificial intelligence) on the Phoenix lander. It is now 40 years since the movie “2001: A Space Odyssey” was released and NASA still has nothing remotely resembling the HAL 9000 computer. Phoenix appears to be a total dummy - it can’t make any decisions on its own and it must wait for direct instructions from humans on Earth before it does anything. Totally depressing given what I was expecting in my youth.
June 25th, 2008 at 2:46 pm
Really? What makes you think that? The Vikings had 4 biology experiments on them:
http://en.wikipedia.org/wiki/Viking_Biological_Experiments
1.) Gas Chromatograph / Mass Spectrometer (GCMS) - failed to find any organic molecules
2.) Gas Exchange (GEX) - Look for gas released from a soil sample after providing a nutrient and water
3.) Labeled Release (LR) - Look for radioactive gas given off by a soil sample to which C-14 tagged nutrient was added
4.) Pyrolytic Release (PR) - Look for radioactivity in the soil sample after being exposed to a C-14 tagged atmosphere
The LR experiment produced positive results. Later it was hypothesized that oxidizing chemicals in the Martian soil were the cause of the positive LR results. You would think that after all these years NASA would be interested in at least repeating these same experiments in the Martian polar region to see if the same results are obtained. Or to track down what the oxidizing agent is (it is still unknown).
Now, this is what is on Phoenix: TEGA
http://en.wikipedia.org/wiki/Thermal_and_Evolved_Gas_Analyzer
It appears to be a slightly upgraded version of just one of the Viking experiments (GCMS). There is no C-14 tagged nutrient, no C-14 tagged atmosphere, no C-14 tagging at all. What makes anyone think this is a step above Viking? It’s clearly not.
June 25th, 2008 at 3:59 pm
Tom Marking said:
> Also, I can’t help but notice the almost total lack of AI (artificial intelligence) on the Phoenix lander.
Name any industrial or commercial application currently using artificial intelligence.
> It is now 40 years since the movie “2001: A Space Odyssey” was released and NASA still has nothing remotely resembling the HAL 9000 computer.
Nobody anywhere has anything like HAL 9000.
June 25th, 2008 at 4:02 pm
We don’t know ‘for centuries’. 200 years ago an icecap was an icecap although it could have been salt.
June 25th, 2008 at 4:04 pm
The bad astronomer said “…regolith (what most people call soil).”
Well, soil is not a synonym for regolith (”dirt” would work better in this context).
Soil has different definitions based on who’s talking:
A civil engineer would say “soil is anything I can cut with a D-9.” (Regolith plus soft rock).
A farmer would say “soil is the black stuff my crops grow in.”
A soil scientist would point out the the farmer’s “soil” was just the A horizon. Soil is characterized by horizons and “pedogenisis” (the physical and chemical processes that turn dirt or rock into soil).
Here on Earth, soil also has lots of living things — which is probably why IRONMANAustraliaon asked “Hey, if they do discover evidence of bacterial life, wouldn’t that mean it’s soil and not regolith?”
But without liquid water, pedogenisis wouldn’t occur, and soil wouldn’t form.
But it’s still REALLY cool to find water ice in the regolith!
June 25th, 2008 at 8:22 pm
http://www.cleverace.com/AI_and_expert_systems.htm
June 26th, 2008 at 5:53 pm
Yes, we knew Mars has water ice.
Yes, it’s exciting for phoenix to have scraped some up.
What’s more exciting is the prospect of those little ovens showing us there’s more than just water ice and regolith under phoenix.
June 27th, 2008 at 3:30 am
Dunno if anyone’s reading this any more, but Emily has a good description of some of what Phoenix is doing - more the wet chemistry than the TEGA, but it’s claimed to be something never done before.
http://www.planetary.org/blog/article/00001526/
As Tom’s link implies, AI has been slow on delivering on its early promise. You’d think anyone who comments on a blog would be capable of noticing that computers are stupid. Expert systems are a million miles from HAL.
June 27th, 2008 at 3:49 am
@Phil , well I wasn’t suggesting anything as It was a question I was asking. But thanks for your info.