CLUES FROM THE RED PLANET
AUGUST 7, 1996
NASA scientists have discovered chemical and mineralogical evidence suggesting single-celled organisms once existed on Mars. The discovery raises new hopes of life on other planets. Kwame Holman has the details on the Martian meteorite that has the scientific community buzzing, and Jim Lehrer talks to scientists about what happens next.
July 10, 1996
Jeffrey Kaye looks at the moons of Jupiter
Pictures of Mars.
JIM LEHRER: Now, to Richard Zare, professor of chemistry at Stanford University and a member of the research team, and Wesley Huntress, associate administrator for space science at NASA. Prof. Zare, President Clinton used the word 'stunning' to describe what you all found out. Is that the word you would use?
RICHARD ZARE, Stanford University: I certainly was stunned myself as I realized what the implications of what we think we've found, but I must say that as you live with this, and we lived with this for two and a half years, you become accustomed to it but at the same time you find that your own view of the world has changed in the process.
JIM LEHRER: Like what? In what way?
PROF. ZARE: To me, it was very much answering this question that I've wondered about, are we alone? To what extent is life unique to Earth? Were the conditions of Earth so special that that's the only place for life? You know, you look at the other planets, and most of them just don't have water. If you look at the first couple, Venus is impossible, Mercury is as dry as a bone, et cetera. And Mars looks like it once had water, and now there's hardly any water there, just traces.
JIM LEHRER: And you've got to have water to have life?
PROF. ZARE: As we understand life--
JIM LEHRER: How do you know that? How do they know you need water on Mars?
PROF. ZARE: Jim, what do I know about life? Truly, all I know about life is what I'm used to finding on Earth, and so in Earth I see that the life I know is very water-based.
JIM LEHRER: Okay.
PROF. ZARE: Right?
JIM LEHRER: Okay.
PROF. ZARE: But maybe I'm all wet. (laughing)
JIM LEHRER: When you started, when you and your colleagues started two and a half years ago, did you have a pretty good idea that you were going to be maybe not sitting here on this program but sitting at that news conference earlier today, saying, hey, we've got a sign or a smell or something that there was life on Mars, or was it all pure let's find out what we're going to do, what we're going to accomplish?
PROF. ZARE: It was certainly a quest to understand a rare specie. Imagine the possibility of holding in your hand a piece of Mars, and that's what we have, that possibility. As the realization came to us that a number of meteorites that have been found throughout the world seemed to come from Mars building on the results of the Viking Lander missions. Without the Viking Lander missions we never would have known this.
JIM LEHRER: Refresh our memory--
PROF. ZARE: Back oh, 20 years ago, I believe. Wes, I don't remember the exact anniversary.
WESLEY HUNTRESS, NASA: 1976.
PROF. ZARE: Think so.
JIM LEHRER: 1976.
PROF. ZARE: And 20 years ago two missions went to Mars and actually deployed landers on the surface that scooped up soil and did various analyses.
JIM LEHRER: And that was compared with--
PROF. ZARE: And also looked at the atmosphere.
JIM LEHRER: And that was then compared with this meteorite.
PROF. ZARE: That's right.
JIM LEHRER: That--that fell in Antarctica 1984, and that's how you are sure that that meteorite came from Mars.
PROF. ZARE: It's this way--now let me say about what sure is here--
JIM LEHRER: Okay.
PROF. ZARE: --because I think--
JIM LEHRER: All right.
PROF. ZARE: There are various levels of confidence in science, and I'm generally not sure of much, sometimes not even of my own name, right? Okay. What am I sure of? It has gases in it that look just like what the Viking Lander found, and there are orders of magnitudes, powers of ten different than what you'd find on Earth. It has a ratio of heavy hydrogen, which we call deuterium to hydrogen in the water, just like is found again on Mars but not on Earth.
It's found in an ice field. You don't find a rock in an ice field in the snow unless it generally comes in there, so it's a meteorite. I'm now with a situation that you see it waddles like a duck and it quacks like a duck, so I say it's a duck, but maybe it's not a duck. If it's not from Mars, it's from somewhere else, and it's still exciting. But I think it's from Mars from what I can tell.
JIM LEHRER: Mr. Huntress, to follow up on Prof. Zare's analogy, did NASA feel that there was a duck at the end of this rainbow two and a half years ago?
MR. HUNTRESS: Oh, I think so. I've watched the duck waddle today, and I'm impressed, and what strikes me about this is that if, in fact, when--we're going to do a lot more work on this to try to confirm that, in fact, the conclusion that they found biological activity in this rock is true--if that's true, then the inferences that life started on a planet in the solar system, other than our own, and if, in fact, it started on two places in this solar system early in its history, then why not others?
And there may be other places in the solar system where it may have started, and if it started on two places in this solar system, then it almost assuredly happened in other solar systems, and we're beginning to find examples of those other solar systems, other planets.
JIM LEHRER: Now define--when you scientists use the word 'life' in this context, what do you mean?
MR. HUNTRESS: What it means is the, the signs of life's activity in this rock.
JIM LEHRER: Human life?
MR. HUNTRESS: No, no.
JIM LEHRER: Animal life, plant life?
MR. HUNTRESS: This is microscopic bacterial life, a very primitive form.
PROF. ZARE: Single cell it looks like, the most primitive thing you can find. In fact, if you look back on what we understand of the fossil records of Earth, it seemed that on Earth there were single cells for something like a billion years. It took nature a long time to figure out how to fuse cells together to make multi-cell creatures, whether they were plants or animals.
JIM LEHRER: But it all starts with that cell.
PROF. ZARE: It seems to.
JIM LEHRER: And that's what you think you have on that rock.
MR. HUNTRESS: Yes.
PROF. ZARE: It looks very much that way.
JIM LEHRER: But you don't know at this stage of the game whether or not there were also other forms of life, in other words, higher forms of life?
MR. HUNTRESS: That's right. This is only evidence for a very primitive form of life early in Mars' history, a billion years after the planet, itself, formed, and so these--and the evidence is, is chemical, it's mineralogical, and we even had images of what appear to be the fossilized remnant structures of these bacteria-like objects, and that's what--
JIM LEHRER: How big are they? Are they--I mean, are they truly microscopic?
PROF. ZARE: Really, you do need a microscope, and, indeed, I think they weren't found without it.
JIM LEHRER: You notice I held up my hand--
PROF. ZARE: They weren't found without advances in, in high resolution electronic microscopy, the type of--only a few instruments in the country, one of them being at Johnson's Space Center, has that capability.
JIM LEHRER: All right, now--
PROF. ZARE: To look at small structures.
JIM LEHRER: Okay. Do you have any, any unofficial private theories, professors there, about where this might go? In other words, if this is there, then based on your knowledge and the knowledge of others about life on, on Earth, what might you then find? Where does it all go? Does it go to this?
PROF. ZARE: I actually expect that if this is confirmed, that we will then make a generalization and say look, we now know that there are other stars that have planets. That's a recent discovery too in the last couple of years.
JIM LEHRER: Other stars? I don't follow that.
PROF. ZARE: There are stars that we see now that have planet systems, have solar systems.
JIM LEHRER: Around them.
PROF. ZARE: Yes, planets that orbit them.
JIM LEHRER: Got you.
PROF. ZARE: Like Earth orbits the Sun.
JIM LEHRER: Okay. Got it. Got it. All right. So--
PROF. ZARE: At least, Galileo and Copernicus and all that, okay.
JIM LEHRER: I got you.
PROF. ZARE: (laughing) And anyways, then I would imagine that the conditions of some of those planets would prevail not so dissimilar from what must have prevailed when life started I assume on Earth and on Mars.
JIM LEHRER: All right now from NASA's point of view, what happens next? This is an exciting discovery. The President says he's going to call a summit. What does the summit do, and then what do you want done?
MR. HUNTRESS: The most important thing to do right away is to try to work to get confirmation of this result. This is a very very fascinating result.
JIM LEHRER: Now where do you go to get that?
MR. HUNTRESS: It's not proven.
JIM LEHRER: Where do you go to get that?
MR. HUNTRESS: Well, this work was done by one group of researchers in this country. There are other research groups that can do work that would add to confirmation or to debate as to whether or not this is really--
JIM LEHRER: There were some today who said, hey, wait a minute, we don't think--they're not--in fact, you even had one of them in your news conference today.
MR. HUNTRESS: Yeah. We wanted to make sure we had both sides of this issue represented.
JIM LEHRER: Yeah.
MR. HUNTRESS: But I certainly expect to get a whole lot of proposals from the science community to work on this rock and to see if we can't confirm this.
JIM LEHRER: How many people are working on this? Is this a major, major undertaking in the scientific community?
MR. HUNTRESS: No. No. This was the work undertaken by a small group of researchers who had the idea to look for biological traces in this--in these Martian meteorites. But I think they've got the attention of a large part of the other science community as well now.
JIM LEHRER: I understand, Prof. Zare, why this might matter to you. This is your life. This is your profession. Why should it matter to me and the rest of us?
PROF. ZARE: Now, of course, Jim, I can't say--it's subjective whether something matters to you or not.
JIM LEHRER: Okay. Why should it matter?
PROF. ZARE: But I think with certain curiosity about the nature of the world you would, yourself, wonder about the nature of life, how it starts. Is it special? How special? We don't know the answers to this. How do you--is it possible--let me just for fun--
JIM LEHRER: All right.
PROF. ZARE: --throw out an idea to you.
JIM LEHRER: All right.
PROF. ZARE: Is it possible that actually we're all Martians, that--what do I mean by that--that life actually first started on Mars and just as we saw came from Mars to Earth and--
JIM LEHRER: You mean via a meteorite?
PROF. ZARE: Via a meteorite. That's right.
JIM LEHRER: Billions of years ago?
PROF. ZARE: I mean, I can't cleave the mold out of my--(laughing)--where I store my bread, okay--cabinet--once I get it infected. How do I know? Alternatively, we really now understand that the planets exchange bodily materials. That's put it that way. I won't say bodily fluids. I'll say bodily materials--okay--back and forth. It's possible that this is actually earthlings, came from Earth and went to Mars and then it's come later back to us.
JIM LEHRER: Okay.
PROF. ZARE: We don't know. Or it started independently. That's fascinating. I think we want to understand that to understand the nature of life.
JIM LEHRER: Does this excite you as much as it does Prof. Zare?
MR. HUNTRESS: Absolutely. I think one of the major questions I'd certainly like to know about, one of the things that's driven me into the scientific field, is to try to understand: are we alone in this universe, and if we find that life originated at more than one place, then I think the answer to that is probably we are not. And so that's, I think, what really excites me the most about the potential for this discovery.
JIM LEHRER: How long will it be before--first of all--you get it confirmed, and then when it is confirmed, how long will it be before we get the answers to all those questions?
MR. HUNTRESS: Well, I think what we're talking about is really a scientific consensus that there's a very high probability that this represents early life on Mars. That could take a year maybe two. In the meantime, we still have and have had even before this discovery came along a program for the robotic and scientific exploration of Mars, and we have two launches coming up this year, one in November and one in December.
JIM LEHRER: So--
PROF. ZARE: So it's research. And in some sense, it's also like writing poetry or great prose, and you don't know how long it'll take. You have hopes that it'll take a few years, less than a decade, but sometimes you get stuck. Okay? Because you don't know what problems you'll run into to make things work. It's hard to give an answer.
JIM LEHRER: Does your team stay in place?
PROF. ZARE: My team consists--I am the professor in which graduate students come and go and so it doesn't stay in place in that sense but there's a constant flow through and I'm hoping that people will be excited and continue this as they have.
JIM LEHRER: How many people are involved in your team?
PROF. ZARE: Right now three people were involved from Stanford. One has already left to--in private industry, another one is leaving soon. More people are joining already. I mean, there is, therefore, training that goes on.
JIM LEHRER: All right.
PROF. ZARE: It's a living process in that way.
JIM LEHRER: All right. And the money is there to do this from the federal government?
MR. HUNTRESS: Well, I'm sure that it will be, to do whatever it is we need to do in order to confirm that, in fact, there may have been life on this planet. It may, in fact, take a sample directly returned from Mars specifically picked in order to really confirm this result.
JIM LEHRER: And that can be done?
MR. HUNTRESS: That can be done.
JIM LEHRER: All right.
MR. HUNTRESS: We know how to do that.
JIM LEHRER: All right. Thank you both very much.
PROF. ZARE: Thank you.
MR. HUNTRESS: Thank you.