and people began coming down [to Caltech] from JPL to see if there was any interest here in planetary exploration.
“I thought [life on another planet] was a plausible idea. Everything that was known about Mars at that time later turned out to be wrong, but [at the time] suggested that there was a good possibility of life on Mars. I had a choice of going into something…taking this golden opportunity to get involved in a new program. And that's what I did. It turned out to be very exciting. Of course, we didn't find life on Mars, but I'm glad I did it.” 1
Horowitz made a decision then and there that would affect not just his life, but the entire search for life on Mars. His move to JPL placed him in the Center for Planetary Exploration, where he would become one of the lead members of the Viking life-sciences team.
“The exploration of Mars became the key idea for a planetary program, for obvious reasons, and JPL set up a bio-sciences section to plan for the biological exploration of Mars, with an eventual lander. They asked me to come up and be chief of their section, which I did in 1965. There was a lot of work going on up there in trying to design instruments to fly to Mars for a biological search, and I got involved in that planning. Two of the instruments that eventually flew on Viking came out of that group. The Gas Chromatograph/Mass Spectrometer, which was probably the most important single instrument on the lander, was designed at JPL.
“When I went up there, that was already in process—it had been anticipated that this would be a useful instrument to have on Mars. What I did get involved with in connection with that instrument was making sure that there was a lot of ground-based experience with it. The instrument is based on empirical patterns of breakdown of organic compounds. You take an organic compound and you heat it until it pyrolizes—it breaks into smaller fragments due to the heating. These fragments can be identified by a combination of analytical steps called gas chromatography and then mass spectrometry. The only thing you have to identify the original compound you started with is the pattern of its breakdown products, and you try to infer the nature of the original compound from these breakdown products. There's not much general principle or general theory you can go on; you just have to have a library of results you can compare your actual results with. We did a lot of that during the years that I was there.”
And this was the key to the search for life on Mars—trying to find a way to identify the building blocks of life by remote observation. To do this, Horowitz's team would have to build up a large database of similar reactions working here on Earth. It was not a trip to Mars, for which many of them would have gladly gambled their lives, but was the next best thing to going there.
“Another thing I did was to get the idea for the second biological instrument that JPL had on the Viking lander. NASA calledit the pyrolitic release experiment; we used to call it the carbon assimilation experiment. It was an experiment that I developed with two collaborators, George Hobby and Jerry Hubbard. The point of this experiment was to carry out a biological test on Mars under actual Martian conditions. It's hard to convey in a few words the total commitment people had in those days to an Earth-like Mars. This was an inheritance from Percival Lowell. It's amazing: in pre-Sputnik 1 days, in fact, up till 1963, well into the space age, people were still confirming results that Lowell had obtained, totally erroneous results. It's simply bizarre!”
And that was the challenge. Horowitz knew by the time he moved to JPL that Mars was not Earth-like in ways that counted toward supporting life, but sometimes he felt that he had trouble getting others to understand it. Oh, they might pay lip service to the thin atmosphere, the extreme temperatures, and the voluminous solar radiation, but living deep in
“I thought [life on another planet] was a plausible idea. Everything that was known about Mars at that time later turned out to be wrong, but [at the time] suggested that there was a good possibility of life on Mars. I had a choice of going into something…taking this golden opportunity to get involved in a new program. And that's what I did. It turned out to be very exciting. Of course, we didn't find life on Mars, but I'm glad I did it.” 1
Horowitz made a decision then and there that would affect not just his life, but the entire search for life on Mars. His move to JPL placed him in the Center for Planetary Exploration, where he would become one of the lead members of the Viking life-sciences team.
“The exploration of Mars became the key idea for a planetary program, for obvious reasons, and JPL set up a bio-sciences section to plan for the biological exploration of Mars, with an eventual lander. They asked me to come up and be chief of their section, which I did in 1965. There was a lot of work going on up there in trying to design instruments to fly to Mars for a biological search, and I got involved in that planning. Two of the instruments that eventually flew on Viking came out of that group. The Gas Chromatograph/Mass Spectrometer, which was probably the most important single instrument on the lander, was designed at JPL.
“When I went up there, that was already in process—it had been anticipated that this would be a useful instrument to have on Mars. What I did get involved with in connection with that instrument was making sure that there was a lot of ground-based experience with it. The instrument is based on empirical patterns of breakdown of organic compounds. You take an organic compound and you heat it until it pyrolizes—it breaks into smaller fragments due to the heating. These fragments can be identified by a combination of analytical steps called gas chromatography and then mass spectrometry. The only thing you have to identify the original compound you started with is the pattern of its breakdown products, and you try to infer the nature of the original compound from these breakdown products. There's not much general principle or general theory you can go on; you just have to have a library of results you can compare your actual results with. We did a lot of that during the years that I was there.”
And this was the key to the search for life on Mars—trying to find a way to identify the building blocks of life by remote observation. To do this, Horowitz's team would have to build up a large database of similar reactions working here on Earth. It was not a trip to Mars, for which many of them would have gladly gambled their lives, but was the next best thing to going there.
“Another thing I did was to get the idea for the second biological instrument that JPL had on the Viking lander. NASA calledit the pyrolitic release experiment; we used to call it the carbon assimilation experiment. It was an experiment that I developed with two collaborators, George Hobby and Jerry Hubbard. The point of this experiment was to carry out a biological test on Mars under actual Martian conditions. It's hard to convey in a few words the total commitment people had in those days to an Earth-like Mars. This was an inheritance from Percival Lowell. It's amazing: in pre-Sputnik 1 days, in fact, up till 1963, well into the space age, people were still confirming results that Lowell had obtained, totally erroneous results. It's simply bizarre!”
And that was the challenge. Horowitz knew by the time he moved to JPL that Mars was not Earth-like in ways that counted toward supporting life, but sometimes he felt that he had trouble getting others to understand it. Oh, they might pay lip service to the thin atmosphere, the extreme temperatures, and the voluminous solar radiation, but living deep in
Similar Books
