Have you heard the big news? NASA has reported that Mark Watney is alive and well on the surface of Mars. No, wait, they’ve reported that there’s water on Mars. Didn’t they already report this? Today we’ll update you on the latest discovery and what this means for the search for life on Mars.
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Computer: This episode of Astronomy Cast is brought to you by Swinburne Astronomy online, the world’s longest running online astronomy degree program. Visit astronomy.swin.edu.au for more information.
Mr. Cain: Astronomy Cast episode 387, Water on Mars Again.
Dr. Gay: Again.
Mr. Cain: Welcome to Astronomy Cast, our weekly facts based journey through the cosmos where we help you understand not only what we know, but how we know what we know. My name is Fraser Cain, I’m the publisher of Universe Today and with me is Dr. Pamela Gay, a professor at Southern Illinois, Edwardsville, and the director of CosmoQuest. Hi Pamela, how you doing?
Dr. Gay: I’m doing well. How are you doing, Fraser?
Mr. Cain: Good. So big new on CosmoQuest front, right? Maybe?
Dr. Gay: Yes.
Mr. Cain: Potentially.
Dr. Gay: Sort of. Well, we are one of the 27 teams that are selected to be NASA education partners for the coming half decade to decade depending on how they renew the funding. We are currently waiting for negotiations on funding to start. This isn’t a grant, it’s a cooperative agreement notice, so we’re going to be getting somewhere between one and a lot of money to keep our programs going. But like all the selected teams we’re still at the waiting to know more than was in the press release side of things, but this does mean that we’re just going to keep growing CosmoQuest for the coming half decade to decade to come.
Mr. Cain: Yeah, we get to do more citizen science with you, our beloved friends and listeners, and we really appreciate all of your support especially through all of the hangoutathons and stuff that really kept the whole machine going to help us get through this – to this next level of funding, and it really means a lot that you guys all supported us while we were sort of in the dark times.
Dr. Gay: And as promised, since we got funding we will do a hangoutathon that is pure science –
Mr. Cain: Pure science.
Dr. Gay: – for it.
Mr. Cain: No money.
Dr. Gay: Yeah.
Mr. Cain: We don’t want your money.
Dr. Gay: No money.
Mr. Cain: Yeah.
Dr. Gay: Just, please, come science all the things.
Mr. Cain: That sounds –
Dr. Gay: Science.
Mr. Cain: – that sound great.
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Mr. Cain: Well, have you heard the big news? NASA’s reported that Mark Watney’s alive and well on the surface of Mars. No, wait, they’ve reported there’s water on Mars. Didn’t they already –
Dr. Gay: Again.
Mr. Cain: – report this? Today we’ll update you on the latest discovery and what this means for the search of life of Mars. All right, so let’s sort of role back here and talk about the previous announcements of the discovery of water on Mars.
Dr. Gay: So it’s one of these things where I think I can go back to 2004 and there’s just this whole string of, and we have more evidence of water on Mars. There are water on Mars, yes, there is. And it’s come in the form of the neutron detections coming off the surface where you hit the minerals with the right high energy particles coming off the sun, the neutrons are released, that’s believed to be evidence of sub-surface water. You have the Mars Phoenix lander that landed in the Arctic regions, went digging down, found white stuff that sublimated, that was evidence of water.
There are surface features that look like they could only have been covered by flowing water. There are minerals, such as hematite that can only be formed if there’s water.
Mr. Cain: The ice caps have water in them?
Dr. Gay: Exactly. But it was long argued that that might just all be carbon monoxide, but everyone’s like no, no, there’s water/ice too.
Mr. Cain: Yeah, there’s water/ice, and carbon dioxide, but, yeah. There’s the blueberries that Opportunity – and was it Spirit found? There’s the, yeah, rocks and chemicals that only could have existed with the presence of water. The stuff that just looks like continents shaped, you know, old oceans and seas and rivers and –
Dr. Gay: Islands.
Mr. Cain: – lakes and islands, so come on, haven’t – didn’t we already know this?
Dr. Gay: Yeah.
Mr. Cain: So what is the discovery that was made just this week?
Dr. Gay: So it’s of the one thing that they had not previously announced was the mostly kind of, sort of, confirmed presence of flowing stuff that is water category. And I phrased that as vaguely as I did because what has been identified is dark streaks coming down cliff walls, the insides of crater walls, during the warm season. So what you see is during the warm season you get what appears to be darkening regions of dirt. If you’ve ever had a leaky pipe you may have noticed your paint getting darker on the inside of your house.
We have leaky furnaces in our house and we noticed this because the ceiling below the leaky furnace will get darker and darker in an expanding ring of, oh we’re going to die, the longer the finance drips. We’re essentially seeing the same sort of bleeding water through stuff on Mars. It is considered to probably be extremely nasty, deadly, would kill you if you tried to drink it water, so we’re talking extraordinarily salty, probably contains some purclorites, but there is some sort of sub-surface source of solidic water.
Mr. Cain: Right.
Dr. Gay: That –
Mr. Cain: And this is –
Dr. Gay: Yeah.
Mr. Cain: – even this isn’t new. I mean we first saw this discovered, I think it was back in 2010, ’11, there was like images from the Mars reconnaissance orbiter and some of the other spacecraft had seen these dark streaks going down craters on Mars in some of the southern regions and one of the theories predicted was that there was some kind of active – as you said – seep, that was sort of causing this darkening down the sides of the craters, and it sort of – they appear and disappear over the seasons.
Dr. Gay: Seasonally.
Mr. Cain: Yeah. But another idea is that maybe there was some kind of underground carbon dioxide, rupture that was sort of sending a cascade of material down, or some other liquid potentially. So watt is –
Dr. Gay: A few people said dark dart was flowing down the sides.
Mr. Cain: Dirt was flowing down the sides, or that there was some kind of strain ice formation that was happening. So would you say then that the announcement that NASA made, I guess last week, was that they – that they’re pretty sure it’s water now.
Dr. Gay: I think the best way to look at the announcement is to say, we have finally beat this problem with a statistical hammer to the point that it is very dead, and with sufficient statistics behind this thing that we discovered half a decade ago, we are now willing to step all the way out and say, yes, this is moisture wetting the dirt in a way that indicates there is moisture of the salty water variety flowing down the insides of these steep crater walls, embankments; whatever they are.
Mr. Cain: So what’s the mechanism that’s probably happening here?
Dr. Gay: Don’t know.
Mr. Cain: Does – has anyone guessed?
Dr. Gay: So –
Mr. Cain: I mean you know, when I look at it here, I’m kind of imagining that you’ve got some kind of ice layer that’s underneath the surface of Mars and this crater has scoped out down through this ice layer and sort of revealed a big chunk and then there’s some – it’s almost like it’s – because it’s seeping out of the crater wall at a certain depth almost that there was like an action happening in these regions that maybe aren’t happening in other places because you’re only getting that – the – that ice layer revealed.
Dr. Gay: Well, so ice layer’s one of the ideas, some sort of a spring-like geology, we have springs all over the earth they don’t flow year round. Some sort of a spring is another kind of idea, so in whatever format is it you have sub-surface liquid either in the form of ice or in the form of pockets of liquid water that seasonally, as the surface conditions change the now not as frozen surface is allowing that water to escape via some mechanism.
Mr. Cain: Right. And so you mentioned sort of that this water was, you know, pretty nasty stuff, what –
Dr. Gay: Yeah.
Mr. Cain: You know what is it – you know, if you could like take a look at a sample of it with good experimental gear what would you probably be looking at?
Dr. Gay: Well, so we know from work done by the various spacecraft that there’s a lot of perchlorates on the surface. We –
Mr. Cain: And sorry, what’s a perchlorate for people who don’t know.
Dr. Gay: It’s a nasty chemical that breaks down organic molecules and could happily kill you, so it’s death basically.
Mr. Cain: And this stuff is across the whole planet, right? I mean it’s right in the –
Dr. Gay: We’ve kind of –
Mr. Cain: – surface –
Dr. Gay: – we’ve kind of –
Mr. Cain: – of the regolith everywhere, it’s no getting away from it.
Dr. Gay: So it’s reasonable to believe we’d probably find it as part of this moist mixture. We know because the stuff isn’t evaporating radically that it probably has a high salt concentration. The properties of water change as you put salt into the solution, so salty water freezes as a different temperature, it evaporates at a different pressure. You add enough salt and it can actually be in the surface dirt without instantly sublimating into the atmosphere. Remove the salt it evaporates faster and you can’t get the effects we see. So in order to explain these lasting dark streaks that grow over the season it’s just got to be salty water.
Mr. Cain: And, you know, so then we talk about it would happily kill you, could anything live in this stuff?
Dr. Gay: Well, the perchlorates probably not, but – I – so that’s not a given, it’s simply a probable. And so there is a chance that maybe the perchlorates have simply been where Phoenix was making its samples, but maybe it’s not everywhere. So if there are areas of Mars where the chemistry at the surface is slightly different, sort of like we have areas of the earth that have high sulfur concentrations and those that don’t. We have areas that have iron deposits, areas that don’t. Depending on what the surface composition is maybe we don’t have perchlorates everywhere that are going to get dissolved in this briny solution.
We do know that there is less life in high saline environments, the Dead Sea is called the Dead Sea for a reason, but it’s possible that perhaps life in the extremophile variety could exist feeding off of this moisture.
Mr. Cain: Yeah, there’s actually microbes here on earth that use perchlorates as an energy source, so they can actually live off this stuff and, in fact, clean out the water a little bit. So microbial life, there’s a possibility that it could do it, but if we try to drink it. I wonder about growing potatoes in it.
Dr. Gay: Probably not. You don’t want to try that.
Mr. Cain: No.
Dr. Gay: Yeah.
Mr. Cain: Probably don’t. I wonder if you could clean out the perchlorate if you – before you want to try and grow your potatoes?
Dr. Gay: Yeah, that’s –
Mr. Cain: [Inaudible] [13:23:15].
Dr. Gay: – actually not that hard to do a simple evaporative system would get you most of the way there.
Mr. Cain: So what is this mean then for what is probably how the water is on Mars, could you drill down and find reservoirs of water on Mar, or is probably going to be this stuff for quite a ways down?
Dr. Gay: Well, this is the type of science release that that leaves you literally scratching your head and going, well, we know that there’s all of these neutrons being given off maybe it’s mixed into the soil, but not as badly as, as like on the moon where trying to get the water of the minerals is next to impossible as reasonable energy thresholds. Maybe this is simply a matter of you can scoop up the dirt, heat it, and the water comes out. I don’t think we’re going to be digging artisanal wells any time soon. It could be that there are small reservoirs that will have the ability to tap into one way or another someday in the future.
Mr. Cain: Now the exploration of Mars has really been this story of searching for the water, you know, they’ve – they – with the Spirit and Opportunity their really looking for evidence that there had ever been water on the surface of Mars in any way and with, with Curiosity they’re really looking for evidence that the conditions on Mars were wet for long periods of time that there could have been life, so can you kind of – when you look at sort of Curiosity and Opportunity’s doing they’re really looking into the history of Mars. And then you look at what these recent observations show. What does this tell us about sort of how we got from then till now?
Dr. Gay: It’s hard to put a complete timeline together where all we have is snapshots. Mars, and its environments are incredibly diverse, where with Gale Crater you have an area that hasn’t had huge amounts of erosion. That’s why the crater is so beautifully crater, it’s not eroded with sand dunes, it’s – still has these old structures on its surface. So with Curiosity we are very much trying to figure out what was Mars. With Opportunity we’re trying to figure out was Mars. And now that we’re finding this current water it’s like, not going to go there, not going to go there. We don’t want to screw up this new current resurfacing that’s going on.
We don’t want to go pollute the water. We don’t potentially want to, like be the Mars rover equivalent of smallpox blankets. So we’re going from, with our probes exploring history to with the at a distance remote sensing spacecraft going this is today. This is the chemistry today. Unfortunately, it’s the rovers that have the ability to start to understand the top several ten of centimetres soil, with Mars 2020 we’re going to be looking into more and more instruments that will probe to greater and greater depths. And that’s where we’ll finally start to get a geologic n understanding of how deep is the different kind of minerals. How deep is the different kinds of brininess.
But now we have to figure out how to sterilize everything in a whole new way because we know that there’s that potential for modern life.
Mr. Cain: Well, there’s – yeah, because, as I mentioned, the – this perchlorate solution is perfectly fine for certain kinds of extremophile microbes, so they could, they would be perfectly happy living in this. And this is sort of one of the big questions that the Viking lander had was like, is there life that’s feeding off this perchlorates system that could be generating some kind out gassing that maybe Viking detected, or didn’t; we don’t know.
But one of the things that’s really interesting we did a lot of reporting on this, on these perchlorates, on Universe Today, and to look at it like it’s like a toxic landfill, like there’s heavy metals and things like that in the soil everywhere and that anyone who actually goes and tries to live on Mars and tries to use this regolith for some kind of purpose is going have to treat this stuff like it’s poison dirt and actually –
Dr. Gay: Yeah.
Mr. Cain: – process the stuff –
Dr. Gay: It’s a super fun site.
Mr. Cain: Yeah, yeah, exactly. The whole planet is a super fun site and that to use any part of it you’re going to have to – they’re going to have to come up with some kind of industrial process to get the perchlorates out of the regolith and out of the water so that they can actually use it. And then once you’ve actually done that then you have to keep the cleaned regolith away from all of the poison stuff. So do you think that – you know, you mentioned the Mars 2020 mission you know does the – this announcement, and this discovery, does that change NASA’s thinking at all about where to maybe send probes? To send landers, and rovers?
Dr. Gay: I don’t know. So speaking as just like normal human being who can tell you that Mars is putting a great deal of effort into trying to flush out the journey to Mars one step at a time, but doesn’t have any inside information. What I can say based on what’s publically available is you can imagine with Mars 2020 there’s going to be a different kind of emphasis on let’s stay away from the millennia so that we don’t accidently pollute them, but let’s definitely work to try and understand more about these fast erosion sites that may be revealing organic materials that maybe we’re going want to increase the sensitivity of our sensors to look for things currently alive as well as previously alive.
Mr. Cain: We talked a bit about this on the weekly space hangout actually last Friday, but the fact is that Curiosity is not allowed to go and check out these sites.
Dr. Gay: No.
Mr. Cain: It’s too dirty.
Dr. Gay: Well, it’s – people don’t realize in general how hard it is to get things clean. My favorite extremophile is this little critter that goes by the colloquial name of Water Bear tardigrade. And these little critters look kind of like gummy worms with extra sets of legs. And if you have them on the outside heat shield of your spacecraft, launch it into space, orbit for a little while, come back to earth exposing that heat shield to the horrors of re-entry, they’ll still be alive.
Mr. Cain: Not of them, but some of them.
Dr. Gay: Not – yeah, and all it takes is some. We – for all we know they’d quite happily eat everything on Mars, or kill in some other viral way. I don’t know what viruses these things might have, and it’s that not knowing that forces us to keep our distance.
Mr. Cain: And so there could very well be microbes, tardigrades, viruses, all kind of things on the outsides of Curiosity?
Dr. Gay: I think it’s safe to say there definitely are human and earth based viruses, bacteria; all of that.
Mr. Cain: And at the very best you sort of confuse the science results if, if Curiosity did try to dig around and see what it might find. It might go, yeah, there’s life here. That’s funny; it’s the life that we brought there. Very similar to the life that was covering Curiosity. But the – sort of at the very worst case is you actually infect Mars with life that then…
Dr. Gay: That destroys native life.
Mr. Cain: Yeah, and so we would never get a chance to really discover it because we’ve turned it into earth life.
Dr. Gay: And archeologically we deal with this here in the Americas all the time. There’s the original fishers and trappers that went through left behind journals talking about the great Mississippian nations and the Canadian indigenous people, and within a few years when we had people going through to make maps all those people were dead. Well, the robots that we’re sending currently don’t have the ability of those fishers and trappers to just spontaneously notice things. We don’t know what we’ve already killed and we don’t want to make it worse.
Mr. Cain: Yeah. And it’s entirely possible that we could. It’s a strange thing for me to think about, just this idea that what if we do find that there is life and we do find that it’s the kind of life that we could affect, should we even be allowed to, to potentially kill the life on Mars to turn it into a world that we could inhabit and eventually colonize, you know? I mean if it’s that fragile is it off limits forever? Like, you know, Uropia attempt no landing there?
Dr. Gay: And that gets really, really difficult because I mean there’s so many different eco systems on Mars. What if there’s highly specialized extremophile for each of those very different climates? There’s no easy way to say, okay, so we’re going to cordon off this area of this valley and area of this caldera, and this area and somehow create little tiny arks in each eco system. If we’re out to terraform the world we’re going to terraform a world and that would mean just like in the Star Trek movie, it would mean destroying all existing life and altering it into that future genesis.
Mr. Cain: Yeah. Even a little scarier is this idea of doing a sample return mission that actually you go down and pick up a sample and then you return that to earth and potentially –
Dr. Gay: Well, not –
Mr. Cain: – infect earth with Martian life.
Dr. Gay: That for some reason actually worries me a whole lot less, mostly because Mars has been very good at sending us samples over the millennia. If you hit Mars with a large enough object you’ll jettison rocks into space that will quite often make their way here where some scientist, probably down in Antarctica walking across the ice will see it and pick it up and bring it home and slice it open, and we’ve done this.
Mr. Cain: Right.
Dr. Gay: Been there, done that, no problems so far.
Mr. Cain: So it’s entirely possible that Mars – I mean this is this idea of panspermia, that Mars has been sending life to earth for billions of years.
Dr. Gay: Or the quote the great original, actually quite bad, Battlestar Galactica, “It’s possible that life here began out there among the stars.”
Mr. Cain: Great. Now we’re quoting Battlestar Galactica for our science.
Dr. Gay: Of course, always, always.
Mr. Cain: I’ll never forgive them for the last episode, anyway – but I’m not going to spoil it.
Dr. Gay: Those last 15-minutes didn’t exist.
Mr. Cain: No, they didn’t happen. Anyway, so I guess now what would you like to see as sort of future of the search for water on Mars? Do you think this is – this has accelerated the whole timeline for what missions are going to be expected to search for and look for? I mean NASA’s approach to this has been so – you know, we talked about this here on Astronomy Cast, they’ve been very thorough, very methodical. Does this sort of jump start a new line of research? Or do you think it’s still –
Dr. Gay: Well –
Mr. Cain: – keep going the same way?
Dr. Gay: So we’re in a really weird position. Prior to the successful landing on Mars Curiosity, we had all at the Lunar and Planetary Sciences Conference very loudly been given the message funding’s not going to keep going to Mars. Funding’s going to start going to the outer solar system and other places and all you Mars researchers need to find new careers, and then Curiosity was success familiar and suddenly out of nowhere there’s a Mars 2020 rover, that we’re like huh? Where did that come from? We didn’t know about that. We haven’t been planning for that. So you’re never quite sure where Congressional mandates are going to come from.
And so I don’t know. And personally what I would love to see is an emphasis on let’s figure out how to get down into the skylights what’s on the Moon and Mars, let’s pilot the technology on the Moon figure it out for Mars. If we’re going go live there we’re going to want to live in those caves. And if there’s life still there it’s going to be in those caves so we need to go figure out what would we’d be living with, but maybe we need to figure out to how to really sterilize things along the way, so let’s practice the technology on the moon, practice the sterilization and go find ourselves a cave to go explore.
Mr. Cain: But there’s something to be said for like for the 2020 rover. Send it to one of these craters where the seeps are happening, let it climb up the crater wall and actually do a sample and try to sort of really understand what’s going on in there before it goes off and wanders the landscape, so I guess it would be –
Dr. Gay: Well, I think Mars –
Mr. Cain: – change in the instruments.
Dr. Gay: – 2020 they’re going to send one of these highly eroded area that would be revealing past organics on the surface that’s pretty well set and you do have to keep in mind the safety. These are steep crater walls where I’d be reluctant to send a beginning climber and a rover is not a skilled as a beginning climber. So unless you want to kill your space probe is the very first you do probably not a good idea.
Mr. Cain: Right, well, you know Opportunity crawled out of a crater and down into a crater, so it’s happened before.
Dr. Gay: On very shallow, shallow areas again linear and steep ones and that’s the problem.
Mr. Cain: Well, so once again water’s been discovered on Mars and this –
Dr. Gay: Again.
Mr. Cain: – this is not the first time that this has been announced and I’m sure it won’t be the last time that it has been announced. And hopefully you’ll have some context for the next time water is announced on Mars. Thanks Pamela.
Dr. Gay: My pleasure, Fraser.
Computer: Thanks for listening to Astronomy Cast. A non-profit resource provided by Astrosphere New Media Association, Fraser Cain, and Dr. Pamela Gay. You can find show notes and transcripts for every episode at AstronomyCast.com. You can email us at info@ AstronomyCast.com. Tweak us at Astronomy Cast. Like us on Facebook, or circle us on Google+. We record our show live on Google+ every Monday at 12:00 p.m. Pacific, 3:00 p.m. Eastern, or 2000 Greenwich Meantime. If you missed the live event you can always catch up over at CosmoQuest.org.
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