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NASA Announces Discovery of Water on MarsAired June 22, 2000 - 11:03 a.m. ET
THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.
DARYN KAGAN, CNN ANCHOR: Talking about some pretty cool scientific news this morning.
Signs of water on Mars has NASA scientists talking. They are about to do it right now in fact. We are waiting for NASA geologists to start their news conference. The topic: is there life on Mars? is there water on Mars?
The Mars Global Surveyor found signs of liquid water, not just ice, that might be present on the Red Planet, and that could mean more of a chance that there was, or possibly life on Mars.
About an hour ago, details of the find were posted on the Web site of the journal "Science." We have our space correspondent, Miles O'Brien, standing by.
Right now we will go live to -- there you are Miles. Miles, why don't we bring you in while we wait for the scientists to start talking. What do we expect to hear?
OK, a little bit of audio problems trying to get Miles. We will work on that. Meanwhile let's listen in to the NASA scientists from Washington, D.C.
(JOINED IN PROGRESS)
ED WEILER, NASA OFFICE OF SPACE SCIENCE: ... water, but there were other ideas and other scientists argue that some lava flows could have caused this or other geological happenings. I think it's fair to say today, the consensus in the scientific community is that, indeed, there was ample water on Mars, billions of years ago, that's billions with a B. And most people really believe now that water was abundant on Mars when it was warmer and a thicker atmosphere, billions of years ago.
Today's results are intriguing evidence for the first time that set that clock back a little bit about a factor of a million or more to a million years ago, perhaps 10,000 years ago, perhaps even yesterday. So that's the key result here.
Nobody, I think, in the community, before these results were shown, even proposed that water might be flowing today on Mars or even a million years ago. The second context, which is important, is biology. Two decades ago, when I took biology in college, it was sort of the Goldilocks theory of biology. If things were just right, life might form, 72 degrees, lots of sunlight, lots of water. The Earth was just right. Mars, too cold; Venus too hot.
But over the last two decades biologists have came up with an intriguing result. Just about any place they find liquid water that's below the boiling point, organic molecules and energy, they find life, whether it's on the surface of the Earth, whether it is 10,000 feet below the Earth, whether it's in radiation dumps, life seems to have a way of finding a way to exist.
Finding liquid water, finding possible evidence for liquid water at some point in the near term on Mars has profound implications for astrobiology. We have not found evidence of life on Mars. We are not saying that we even found evidence for past life on Mars. What I want to emphasize, if these results prove true after the scientific process takes its course, this is the first step in the science process, getting the results out to the other scientists and the public, if these results prove true, that there is water on Mars, near the surface, it has profound implications for the possibilities of life on Mars.
And a question everybody asks is: So what? what does this mean? The last thing I'll point out is that we are one sun in a galaxy of hundreds of billions of stars. We are one galaxy in a universe of hundreds of billions of galaxies. We know solar systems are probably common. Hubbell has seen proto-planetary systems being formed around many stars that we look at. We have found 40 planets, admittedly not Earth-like planets, but planets around other stars.
If the very first place we look in the universe in-depth, we find life, either past or present, that has profound implications for the ultimate question: Are we alone?
So now we'll get to the actual scientists who did the work and hear about the evidence they have found for potential water on Mars, Dr. Mike.
MICHAEL MALIN, MALIN SPACE SCIENCE SYSTEMS: First, I'd like to thank you all for coming on relatively short notice; and, second, I would to thank NASA, the Jet Propulsion Laboratory, and the journal "Science" for supporting this activity. I think you can all understand how daunting it would be for me to host you at my 12-person company in San Diego. It's not within our technical means.
And finally I hope you are not disappointed by what we're about to share with you, given all the speculation over the last couple of days, sometimes the actual observations sort of pale in comparison to the science fiction that has been written. But I'm very excited about it, and I hoped in the next couple of minutes to convey some of the reasons I'm excited to you. As a little bit of background, I need to remind you that the camera that took these pictures is on a spacecraft that has been orbiting Mars for over two years. About a year ago, this camera got to the orbit, the spacecraft got to the orbit that it was designed to operate in, which is a 400 kilometer, circular orbit in roughly a polar orbit. that allows us to really pass over much of the planet over the course of Martian year.
And in the first three months of the mapping orbit mission, which began in March, the first thing we did was focus the cameras, we had not focused it until it was in the relatively benign thermal environment of the planet, because it is very sensitive to temperature. Once we got it in focus, we then had a whole list of things that we wanted to study with this camera for many years, and we went through fairly methodically the list of things that we were looking for.
And, of course, we were looking for things we already knew about or we suspected, and as always the case in exploration, it's the things that you don't anticipate that are the things that ultimately turn out to be the most exciting.
We spent a month looking at low resolution at the whole planet trying to get a snapshot of it. And we followed that month of operations with a month searching for a landing site for the Mars Polar Lander.
During the month that we were searching for Polar Lander, we also began our general surveys, we started just taking pictures not randomly, we have a process where we actually target things based on where the ground track of the orbit is, but we started taking other images. And in the month of July, the first of these features showed up, and we didn't quite recognize them in the first -- in our first view through the pictures, but as we saw more of them, and saw the pattern with which we were finding them, we were quite surprised and confused by it. Because, in fact, it doesn't really fit our models of what Mars is like.
So with that, let me start with my first graphic, please. This is a gully, exactly how the gully formed, we do not know, but it's a gully. The scale in the lower right, the 440 yards, that's a couple of city blocks, and you could walk the distance across that bar in a few minutes, to give you a scale for the -- a feel for the scale of these features.
That's a hill, actually it's the rim of an impact crater that's much larger than that picture. And you can see that there are a number of attributes of that, which I'll discuss in a second, that we as scientists can use to classify this land form, and how it's composed.
And if I can go to the next graphic, you'll see on the left an example on Mars, and on the right a very, very much smaller example from some research I did at Mount St. Helens right after the eruption, that gives you an idea of what the features are that we are using to classify these and interpret these land forms as having been formed by water.
And there are basically three elements to the shape or the aspect of this. The first is at the top -- could I go back to the graphic, please? -- at the top is an alcove. That's a collapse area where material has moved down and away off the wall, down lower onto the slope of this crater's wall. In the middle, there are channels that are both conduits that transported material. And they're actually cut into material that was earlier transported by an earlier phase of the development of this feature. And then at the bottom you can see that there's this smoother area, which we call an apron, which is where material has been deposited.
So, material starts up at the top and then moves down to the bottom, both under the influence of gravity primarily. It's pulled down just like a landslide is pulled down on the Earth. And, in fact, this very much resembles some terrestrial landslides. And then the channels are material -- things that have been cut into that apron during the transport of other materials.
And you can see that on the right in the channel from -- or in the example from Mount St. Helens, this a much smaller feature. That little color bar in the upper right inset is 30 centimeters across. So that's a very small feature, but it shows the same aspects. And this is where water in the soil at Mount St. Helens, in the ash from the eruption, was percolating through the ground and removing material and spreading it out in an apron at the bottom.
The next graphic shows a very good example of what we see in a relatively limited number of places, where you have a whole -- a large number of these areas, these land forms, that are all heading or starting at the same layer in rock. That layer is about 150 or 200 meters beneath the surface, and you can see the concentration of the process that forms these land forms, these aprons and alcoves and channels. And you can see that each unit has the same aspect. It has a collapse feature at the top, it has a channel, it has the apron and material at the bottom.
In -- had this been on the Earth, there would be absolutely no question that water was associated with the formation of this material -- this feature because we see these things all the time. This could be called a "weeping layer," for example, and we find these in the Colorado Plateau, for example.
The next graphic shows the distribution of these, and this is really the perplexing problem for us, and this is what caused us to think about all sorts of other explanations. This is a map of Mars, going from pole to pole, top to bottom, and across the 360 degrees of longitude. The light dot -- the white dots are the locations where we have found these features. And they're very rare. We've seen them in only about 200 or 250 images of the 65,000 that we've taken.
And they have a very unusual distribution. First, they are fall -- they are found almost exclusive poleward of 30 degree. That is, north of 30 degrees north, and south of 30 degrees south. So the equatorial region, which is the area that we have always thought would be the location where you would find the most evidence of water on Mars, is devoid of these features.
The second attribute that was also very puzzling is that they are found predominantly on surfaces that face away from the equator. So in the south, they're found on South-facing slopes. And in the north, they're found on north-facing slopes. Together, those two attributes being poleward of 30 degrees and pole-facing, means that these features form on the coldest locations on the planet -- or the coldest locations at any given latitude, which is exactly opposite of what you would have expected for something to be conducive to liquid water.
Finally, if you go again to the graphic -- if I could have the graphics, please -- you can see I've marked four areas in blue. It turns out that the predominant number of these occur together in very small or localized clusters, so that you can see there's a -- almost a random distribution of points in the south polar -- in the southern hemisphere. And then there are maybe twice as many in just a few small locations. And the fact that these sort of cluster together is also telling us something very important about the formation mechanism.
And with that background to the morphology but without telling you what we actually think, I'm going to turn it over to my colleague, Ken Edgett, who will tell you a little about the age and other attributes of these features.
KEN EDGETT, MALIN SPACE SCIENCE SYSTEMS: OK, I'm going to start by just describing why we think these features are young, and then I'm going to get into why we think they have something to do with water.
If we can go to the first graphic, this one basically shows some of the evidence that these features that Mike Malin has just described are young. The very first picture on the left I think is the one that blows my mind the most. You see one of these gullies or channels coming down a slope on the wall of -- near Galvalis (ph), and you see its apron, the deposit of material from that, is on top of a field of sand dunes.
Sand dunes tend to be fairly young features whether you find them on Mars or the Earth. In fact, those sand dunes are young enough that there are no craters on them. And geologists studying planets use craters to tell you how hold something is. The channels don't have craters, the aprons don't have craters, and the things that they are on top of, like these dunes, also do not have craters. From a geological point of view, that means these things are very, very young, just like North America. There are very few craters in North America.
The picture in the middle a little more complicated, but you're looking at some aprons coming down the side of a crater wall. But surrounding those aprons, you see this pattern that kind of maybe looks like a basketball surface -- the surface of a basketball or something. Those are little polygons that form in arctic environments, antarctic environments. You find these in Alaska, for example. Those kinds of features form by the cycling of warming and cooling or the freezing and thawing of ice in the ground in the Arctic. Now on Mars, whether that's the same thing or not is not completely known. But polygons like that on the Earth would only be few thousand years old at most, maybe 10,000 at most, or they could be very, very young -- hundreds of years.
So you're, again, looking at materials that are aprons of debris that are sitting on top of things that are already fairly young to begin with. The aprons have to be younger than the polygons.
The picture on the right shows an alcove portion of one of these other, you know, gully features that we found on Mars. And here you see a variety of bright and dark surfaces. Bright and dark surfaces really close to each other like that in that picture there on Mars is very unusual unless you're in an area where there's some process that is actively removing dust. Dust on Mars seems to settle out all the time. Sojourner, for example, saw dust settling on it for the whole 83 days that it was operational in 1997.
The dust is being cleaned off of these surfaces by some processes. Now, obviously, this is a slope and material is coming down the slope, and so there is some landslide activity. But there is also a very fine little channel running down that slope, coming out of the rock and down the slope. And so that's another one of our examples.
So these things are so young. The dust one is the one that bothers me the most because that would tell you that something is happening on these slopes right now or, you know, within the last year or two. So that really bothers me.
We were -- I was dragged kicking and screaming to this conclusion. Mike Malin has done field work on Earth in places very similar to the places we're describing here today, but I haven't been out there and I was very much disturbed.
One of the things we did was, do these things really involve water? What other processes modify slopes on Mars? Let's go to the next slide. The point is that there are way -- there are other slopes on Mars where things move down slope but they're not wet, they're dry.
And there are two examples. The one on the left and the one in the middle are the types of things we see on Mars that we know are dry, mass movements. That's what geologists call material coming down a slope, is a mass movement.
The slope on the left is in the Valles Marinaris, a big canyon at the equatorial regions of Mars. And you see a bunch of streaks coming from the upper left down toward the lower right. That's all the debris: rock, sand, dirt, coming down that slope. That's happening dry. The one in the middle shows a bunch of dark streaks coming down a slope, and they even look almost fluid. Some people look at these and say: Wow, that's seepage, right?
No, those are actually avalanches of dry dust coming down the slope, leaving little scars, if you will. And we've actually seen those things changing over time, during the course of our MGS mission. But the one on the right is one of our gullies with the alcove channel and apron features. And the one thing to notice here is that the -- first of all, the alcove is very deep here relative to the tops of the slopes in these other pictures. And second of all, the apron itself, toward the bottom center of that picture on the right, is more like a low bate, flow-like feature, a very different shape, very different morphology. It has relief as well -- thanks.
These features we're talking about today are very different than the things we know on Mars happened dry. But I'll be honest, the thing that convinced me the most that these things have to have something to do with water is the associations that Mike Malin showed. These things have a relationship to sunlight. It's backwards. It doesn't make any sense. But they -- because they occur at certain latitudes on Mars, even though they are away from the equator, and because they tend to occur on slopes that point away from the sunlight, that's telling you that whatever material is involved in creating these features is something that responds to heating from sunlight, or in this case, responds backwards from what you would think.
So what we've done with taking all this stuff and pulling it together, is we've come up with a little sketch. If we had another week, we would have had a cool animation, but we'll show you the sketch. And what you're looking at is -- we showed a picture earlier. You saw that something had come out at a specific layer and gone down a slope. In this cartoon, you see a bluish layer with an arrow and some dots in it. This is a layer, a permeable layer in the rock, in the crust of Mars.
These are typically within a few hundred meters of the surface, so less than half-a-kilometer, and water -- this happens on the Earth all the time. Water percolates through that layer. It eventually emerges and goes down the slope. As that goes down the slope, which is that green stuff there, as you're getting all this debris and you've got these little red rocks coming down the slope. As it comes down the slope, it erodes the layer from which it's coming. So the layer itself eats backwards into the slope, which causes that -- you see that purple...
KAGAN: We've been listening to some interesting scientific findings from scientists at NASA, talking about the discovery of water on Mars. Now, the scientists explaining that, there for a long time has been a belief that billions of years ago, there was water on Mars. But now they're talking about as little ago as a million years ago, 10,000 years ago, or even right now in the present day. And, of course, that plays into the question of whether or not there could be life on Mars.
For more on this finding and this news conference, let's bring in our space correspondent, Miles O'Brien, also standing by in Washington with more on this.
Miles, neat stuff.
MILES O'BRIEN, CNN SPACE CORRESPONDENT: It is neat stuff, Daryn. And the time frame is the key issue here. The issue of water on Mars has never been really in debate, or at least in recent times. At one time, many billions of years ago, the planet was filled with water and it was much warmer. The question has always been: Where did the water go? Well, scientists may be on the verge of finding that answer. What they're finding, essentially -- and there's a lot of scientific jargon there, so you have to sort of sort through it a little bit -- but essentially what they're saying is, there's an aquifer underground.
And this aquifer is spewing out water. Now typically, water, when it reaches the atmosphere of Mars, which is very cold and very thin, water almost simultaneously boils, evaporates, and freezes. So you would not expect to see any sort of flow. But what they're suggesting is sort of ice dams build up in these porous locations. And the water builds up behind it and then it spurts out. And that gives what, in effect, a brief water flow, and giving them the evidence that there might be water activity right now.
Why is this important? Water is important because wherever you go on Earth, if you find liquid water, you find life. Let's take a look at some of these images. To the right of your screen is Mount St. Helens, here on Earth. This is just for use by comparison. To the left is Mars, from the Mars Global Surveyor spacecraft, about 400 kilometers above the surface. And just to give you a point of reference, the smallest thing you can see there is about the size of a sport utility vehicle.
Now, that alcove you see there is essentially a place where sort of a flash-flood effect has occurred. And then you see where they've pointed out channels. Essentially, that is the effects, they believe, of recent water flows down a slope. The aprons are where it is all depositing. Now, it turns out that Mike Malin, who is the chief executive officer of Malin Space Science Systems, the people who designed and built this camera, which is on the Mars Global Surveyor, has studied Mount St. Helens. And he immediately saw some parallels here.
Now, of course, the one thing you've got to remember here is, no one has found a Martian swimming hole here. There is no pictures from Mars Global Surveyor of bubbling springs on Mars, so we're still dealing with evidence like you're seeing right here, which indicates these gullies. These gullies, according to scientists, would lead them to believe they were formed by liquid water. Very surprising announcement, given the fact no one expected to see liquid water survive on the surface, for the reasons I just told you.
Now, what this all means for scientists here at NASA -- well, first of all, it's a bit of good news after a long stint of bad news. The loss of the Mars Polar Lander left them very red-faced and they've been trying to explain their faster, better, cheaper program ever since. But as they look toward regrouping, and sending additional landers to Mars, Daryn, these sites will be of high interest. It's very likely this will help them pinpoint landing zones, which would allow them the opportunity to perhaps independently verify if there is in fact water there. And then the question is: If you find water there, are there going to be tiny microscopic organisms there? And then that opens up a whole -- well, I guess you could call it a can of worms, Daryn.
KAGAN: A can of worms found on Mars. No, not really.
Miles O'Brien, bringing us the latest on that NASA news conference.
And very interesting and fascinating stuff, and even more to learn ahead.
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