Opportunity found evidence of water in Martian rocks. El Capitan (upper) and Last Chance (lower) (Courtesy of NASA/JPL-Caltech/Cornell)
Q. What is the reason America is particularly interested in Mars?
Well, I think it has to do with the fact that there's compelling evidence that Mars is a water-rich planet. As we understand it, water is the requirement for life here on Earth. You must have water to have life, and Mars is the only other planet in our solar system that we know has had water on its surface. And the indications are that water may have been stable on its surface about four billion years ago, which is when life started here on Earth. And so, will life start anywhere where liquid water is stable, or is this a one-chance-in-a-billion happenstance occurrence? Are we just really lucky, or will it happen anywhere? That's a question you can address with robotic explorers that are fairly modest in cost. It goes directly to the heart of this aching question of, are we alone in the universe? Are we really lucky to be here or... can life exist anywhere? So I think that sets Mars apart from most of the other bodies in our solar system.
Well, I think it has to do with the fact that there's compelling evidence that Mars is a water-rich planet. As we understand it, water is the requirement for life here on Earth. You must have water to have life, and Mars is the only other planet in our solar system that we know has had water on its surface. And the indications are that water may have been stable on its surface about four billion years ago, which is when life started here on Earth. And so, will life start anywhere where liquid water is stable, or is this a one-chance-in-a-billion happenstance occurrence? Are we just really lucky, or will it happen anywhere? That's a question you can address with robotic explorers that are fairly modest in cost. It goes directly to the heart of this aching question of, are we alone in the universe? Are we really lucky to be here or... can life exist anywhere? So I think that sets Mars apart from most of the other bodies in our solar system.
Mars Atmosphere and Volatile EvolutioN (MAVEN) (Courtesy of NASA)
Q. Please tell me about the future of NASA's Mars program.
Right now, there are five spacecraft either on the surface or in orbit, four of which are run by NASA. So, the next mission, in 2011, will be a large rover called Mars Science Laboratory. In 2013, there is a mission called MAVEN, which is an orbiter that will determine the atmospheric composition and the escape rates – how fast the atmosphere is being stripped by the solar wind – to better understand what the early atmosphere was like. By studying these processes of how the atmosphere is lost to space, you can calculate the composition of the early atmosphere and determine if it was thicker. And you need to have a thicker atmosphere to have liquid water stable on its surface. Today, the atmosphere on Mars is so thin that there can be no liquid water on the surface. You need to add more atmosphere, make it thicker and higher-pressure. With higher pressure, you could potentially support water on the surface. And then there's discussion, but it's very early still, for something in 2018, perhaps a lander or a rover mission from NASA, but that's not very well defined. So, there are still quite a number of missions that could add substantial new information about water.
Q. What is the next goal for you personally, in the next five years?
Right now, there are five spacecraft either on the surface or in orbit, four of which are run by NASA. So, the next mission, in 2011, will be a large rover called Mars Science Laboratory. In 2013, there is a mission called MAVEN, which is an orbiter that will determine the atmospheric composition and the escape rates – how fast the atmosphere is being stripped by the solar wind – to better understand what the early atmosphere was like. By studying these processes of how the atmosphere is lost to space, you can calculate the composition of the early atmosphere and determine if it was thicker. And you need to have a thicker atmosphere to have liquid water stable on its surface. Today, the atmosphere on Mars is so thin that there can be no liquid water on the surface. You need to add more atmosphere, make it thicker and higher-pressure. With higher pressure, you could potentially support water on the surface. And then there's discussion, but it's very early still, for something in 2018, perhaps a lander or a rover mission from NASA, but that's not very well defined. So, there are still quite a number of missions that could add substantial new information about water.
Q. What is the next goal for you personally, in the next five years?
Comparison of sizes of Mars Science Laboratory (left) and Spirit (right) (Courtesy of NASA/JPL-Caltech)
Water ice in a Martian crater found by Mars Express (Courtesy of ESA/DLR/FU Berlin (G. Neukum))
I'd love it if the rovers – Spirit and Opportunity – were still operating. I think in five years, we will have come up with a landing site for Mars Science Laboratory. I would hope to be on the science team to help work with the data after we land and look around. MSL is the size of a small car, and it has much more sophisticated instruments that will give us definitive mineralogy and much more definitive chemistry than what we have with the rovers now. We've narrowed down our choices to four locations on Mars that have very interesting characteristics. They all have the spectra that indicate an ancient wet environment, and many of them show layers exposed at the surface, so we can drive up and do stratigraphy, go from layer to layer, and by studying the rocks see what the environment was, how those materials were deposited, was it wet, was it in a standing body of water, those sorts of questions. The rover can look at those sedimentary layers and determine the environment that they formed in, whether there was any biogenic residue, whether there are any organics or anything left over that would indicate that there was life there at one time. That will be a substantial next step in our Mars program.
I hope to be helping the Europeans select a landing site for ExoMars, which is an ESA mission, in 2016. That's a sophisticated rover with different instruments than Mars Science Laboratory.
I also hope to be involved in the acquisition of the data from MRO (Mars Reconnaissance Orbiter), from HiRISE and CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) for future landing sites. There may be a lander in 2018 and perhaps even eventually a sample return. And we'd like to use MRO now to begin to scout out locations where we might send future landers as well.
I hope to be helping the Europeans select a landing site for ExoMars, which is an ESA mission, in 2016. That's a sophisticated rover with different instruments than Mars Science Laboratory.
I also hope to be involved in the acquisition of the data from MRO (Mars Reconnaissance Orbiter), from HiRISE and CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) for future landing sites. There may be a lander in 2018 and perhaps even eventually a sample return. And we'd like to use MRO now to begin to scout out locations where we might send future landers as well.
Q. Do you think anything will change for your project under the administration of President Barack Obama?
There will be a new NASA administrator, and there will likely be a changes. How much that will affect the Mars program, I don't know. But I would guess that the previous president had some very specific ideas about sending people to the moon and then to Mars, and whether the current president has those ideas or not, we can't tell. The new president has not defined new space policy yet. Our process in America is that the new president and the administrator get a lot of say in what happens. And if they decide that the direction that NASA needs to go in should be different, there could be far-reaching changes. I'm hoping that the Mars program has been successful enough that they would see value in it.
Q. What are your hopes for future planetary missions from Japan?
I know they've been sending missions to the moon, and they sent one, of course, to the asteroid as well. So, it's up to Japan to decide where to go, but we would love to have Japan interested in Mars exploration, and I'm sure we'd all be interested in helping out in any way we could.
Q. What is the greater meaning for humanity of doing planetary exploration?
There will be a new NASA administrator, and there will likely be a changes. How much that will affect the Mars program, I don't know. But I would guess that the previous president had some very specific ideas about sending people to the moon and then to Mars, and whether the current president has those ideas or not, we can't tell. The new president has not defined new space policy yet. Our process in America is that the new president and the administrator get a lot of say in what happens. And if they decide that the direction that NASA needs to go in should be different, there could be far-reaching changes. I'm hoping that the Mars program has been successful enough that they would see value in it.
Q. What are your hopes for future planetary missions from Japan?
I know they've been sending missions to the moon, and they sent one, of course, to the asteroid as well. So, it's up to Japan to decide where to go, but we would love to have Japan interested in Mars exploration, and I'm sure we'd all be interested in helping out in any way we could.
Q. What is the greater meaning for humanity of doing planetary exploration?
I think it goes back to that humans need to explore, and space is an open frontier that gives people a different venue to look at. We've probably explored most of the places on Earth. How was Earth different from other planets, how lucky are we to even be here, are we the only intelligent life in our universe, in our solar system, how common is life, are we alone? These kinds of questions go beyond the day-in and day-out routine that we have.
Science is a process of discovery and exploration. That's the exciting part. You don't know what you're going to learn until you go and try to find out. You keep finding out more and more answers, and you keep finding more questions to ask based on what you've learned. But you never reach an end. It keeps going forever.
Science is a process of discovery and exploration. That's the exciting part. You don't know what you're going to learn until you go and try to find out. You keep finding out more and more answers, and you keep finding more questions to ask based on what you've learned. But you never reach an end. It keeps going forever.
