A New Mars
29 Aug 2006
(Source: Astrobiology Magazine)
When two Viking landers set down on the surface of Mars in the summer of 1976, Gentry Lee was there to witness the first images beamed back to Earth. As director of science analysis and mission planning, Lee was responsible for the daily activities of Viking scientists during the mission. In addition to working on other NASA missions such as Galileo and the Mars Exploration Rovers, Lee is a science fiction writer and has collaborated with Arthur C. Clarke on several novels. He also worked with Carl Sagan to develop the TV series COSMOS.
At the recent thirtieth anniversary celebration of the Viking mission, Lee, now chief engineer for the planetary flight systems directorate at the Jet Propulsion Laboratory, discussed the excitement of landing on Mars for the first time, and how far we've come in our Mars explorations since then.
"For those of you who have wondered if I've lost my passion for exploration, the answer is absolutely not. If anything, it's greater now than it was back when I was a strange long-haired kid who wore strawberry pants".
A lot of us in that particular generation were wondering what we were going to do that would give us a sense we were accomplishing something. And never have I done anything with the passion that I did Viking. It set a very important mark in my life.
Some of you may know that after the Challenger disaster, when the Galileo mission was essentially ready to fly, I had a long list of things that I wanted to try to do. So I wrote a few novels, I designed a few computer games, I did a few other things that I'm not going to tell you about because they were so terribly unsuccessful. After I worked all those things out, I said, "Ok, list complete. What do I want to do for the rest of my life"?
There is only one thing I have ever done that I always felt was worth it. And that is being a part of the only generation that will ever explore the solar system for the first time.
In the 25th century, when the history books look back on the time that you and I and the Vikings were alive, the chapter will not even mention George W. Bush or whoever succeeds him. It will simply say, "It was the Golden Age of space exploration." And it was Viking that sounded the first real score, in my opinion, in that entire planetary exploration saga.
As long as I live, frozen in time will be the moment when those few lines came in after we touched down, and I heard Tim Munch say, "Goodness" in his soft, gentle voice. The excitement was palpable, and I was shouting, "Hip hip hurray," and all sorts of other things that only long-haired 32-year-olds shouted. It was a wonderful time.
For those of you who don't know why I'm still working, I have seven sons, and five of them are under the age of 20. They asked me what we were going to do today, and I said we're going to talk about Viking and how wonderful it was, and what an incredible team it was, and the esprit de corps and the passion and how we felt and what its legacy is, and what we've learned since then. My 15-year-old said to me, "Can you summarize in 3 to 4 minutes, because that's all the time I have, what it is we've learned since Viking"? And I said, "Ok, I'll give it a try."
First, there's the unsung hero - the Mars Global Surveyor, the mission no one's ever heard about. It did a fantastic job. Its orbital laser altimeter gave us a sense of the elevation everywhere on Mars. It basically gave us the globe we have today and the sense of what we're doing. It also had a thermal emission spectrometer on it, with which we identified a possible water-laden mineral of hematite. That then became the fundamental piece of information from which we made the decision to land at Meridiani with one of the two Mars Exploration Rovers, and that of course is where we found the outcrop and the first initial sense that there had been water there for a long period of time. So all these things are tied together.
Pathfinder, from a scientific history point of view, did not add much, but that's not important. Pathfinder re-engaged the public. Following that, there was an Odyssey mission that took gamma ray spectrometry and determined with its neutron detector that there was water pretty close to the surface in lots of places, and then we had the most recent mission, the Mars Exploration Rovers.
There's one mission that in the United States has not received as much play as it should have. If you spend any time in Europe, you know how jubilant they are about the successes of Mars Express. Mars Express has been in orbit for a couple of years, and it has made some fundamental discoveries. I'm not going to enter the debate about whether or not methane has been found. They announced that they found methane and other people have announced that they didn't, but nevertheless it is at least an interesting scientific puzzle that needs to be worked out.
What I am the most surprised and delighted by are the observations made by the OMEGA spectrometer, which has identified not only the sulfates, of the hematite variety and many different kinds, but also what are called phyllosilicates, or clay minerals which, the geologists tell me, means there had to be standing water for extended periods of time. So the Mars Express observations have set up a new picture of the evolution of the planet. Once again we have a new Mars that has emerged.
Think about it. A new Mars emerged in '71, with the Mariner observations. A new Mars emerged with Viking. Another one with Mars Global Surveyor. Another one with MER. Now still another one with Mars Express.
We are so lucky. This is only going to happen to us. Five hundred years from now, maybe someone will be finding something new about Mars, but it'll be some rare, isolated discovery. What is happening in our lifetime is the emergence of another world. It has given us the ability to think about what we are, and who we are, and where we are going in a way unlike we've ever been able to do before.
Did life start on Mars? If not, why not? If so, was it knocked off of Mars and carried to the Earth, and perhaps formed the beginnings of life on Earth? These are wonderful puzzles, and as the days pass, we're learning more and more about how to answer them."