Philip R. Christensen is a Regents Professor of geological sciences and the Ed and Helen Korrick Professor in the School of Earth and Space Exploration at Arizona State University. Image Credit: Arizona State University

Where are you from?

I was born in Utah, and I lived in Kansas until about the age of 12. I then moved to Los Angeles, Calif. and went to high school in Arcadia and then the University of California at Los Angeles (UCLA) for college. I now live in Tempe, Ariz.

Describe the first time you made a personal connection with outer space.

I am a product of the Apollo era. I was about 10 years old when the astronauts were first going into space, and I fell in love with it.

I always tell students that if you want it bad enough you can do it. It has been my experience that the people who are really passionate about space exploration always found a way to do it.
- Phil Christensen

I do have a vague memory of my parents taking me outside to see Sputnik at the age of 5. I don't remember seeing it, but what I do remember is being outdoors with a bunch of adults who seemed to be worried about something -- something I didn't understand at the time.

When I was in the sixth grade I talked my mom into letting me stay home from school to watch live pictures coming back from Mars on television. (I thought that it was pretty cool that we were getting live pictures from Mars.) My Mom wasn't one to let you skip school for any old thing, but she let me do that, and I have been a Martian ever since.

How did you end up working in the space program?

I always was interested in space. It never really occurred to me though, that I could be a NASA scientist myself. (The mentality was and still is today that you have to be someone special to be a NASA scientist.) I was getting a degree in geology at UCLA and working for an oil company, when I met a professor named Hugh Kieffer there. Hugh Kieffer was looking for an undergraduate student to work in his lab. I talked to him, and he offered me the job. (This job had me cutting up pictures from the Mariner mission.) In working for him, it suddenly dawned on me that, yes, I could work for NASA, and that working for NASA could be a career for me. I changed direction, and began taking a lot of physics courses so I could work with spacecraft data and computer models, but I've always remained a geologist at heart. I ended up going to graduate school with Hugh Kieffer to study the planet Mars.

Who inspired you?

From a distance, the guys who were sending men to the Moon inspired me, but at home, my mom was a major influence for me as a kid. She recognized that I was interested in space and bought me a telescope. She really encouraged me to do well and follow my interests.

And Hugh Kieffer was my role model. He was an extremely good scientist, and a really good human being. He is, in my mind, an example of how you do science. He had great integrity, honesty and he was just brilliant. He was a great inspiration.

What is a Planetary Geologist?

Much of my work involves being the Principal Investigator (PI) of Mars projects, such as the Thermal Emission Imaging Systems (THEMIS) for the 2001 Mars Odyssey mission. I run these projects, manage research groups and write proposals. I try to do some research myself and I teach. I am a professor at Arizona State University (ASU). I really enjoy it. I teach a freshman class, upper division and graduate courses on the planet Mars.

Tell us about a favorite moment so far in your career.

One of the most memorable moments was when I was a graduate student and working on the Viking project back when it landed in 1976. I got to be in the same room as Carl Sagan, Bruce Murray and all the scientists from the Viking project (I think Arthur C. Clark and Ray Bradbury were there as well). They were all sitting around and debating about what we were going to be able to see once the craft landed and started taking in data. (At that time we had no idea if there was life on Mars or not. So far the images we had seen from Mars had all been from orbit and the smallest thing we could see was no smaller than a football field.) I remember Carl Sagan arguing that he thought that there would be vegetation, for instance lichen growing on Martian rocks. It was great to sit there and hear their debate and at the same time know that in only 12 short hours, we would find out the truth. It was a pretty spectacular moment.

What advice would you give to someone who wants to take the same career path as you?

I meet a lot of undergraduate students who just assume that they could never get a job working for NASA, but it isn't true. You don't just have to be an engineering or physics major. I was a geology major and it worked out for me. Or students say: "It is too competitive." "There aren't many jobs." Or: "Will NASA still be exploring Mars by the time I graduate?" I always tell students that if you want it bad enough you can do it. It has been my experience that the people who are really passionate about space exploration always found a way to do it. So just be committed, be passionate about it, and you will find a way to be involved in space exploration.

What do you do for fun?

My hobbies have varied over time. Lately, I have gotten into woodworking. It is great to be able to use my hands rather than just my fingertips on a computer keyboard. I try to get outdoors to hike. (I became a geologist so that I could work outside.) And I have a salt water aquarium at my home -- two tanks. One is 350 gallons and the other is 250 gallons. They are a lot of fun, but they do take a lot of my time just maintaining them, and the animals inside are finicky -- they let me know if the water is not to their liking.

If you were talking to a student interested in science and math or engineering, what advice would you give them?

Take as many quantitative subjects (math, chemistry, and physics) as you can. Planetary science has really grown so that it is really a quantitative field. So you can never have too much math, chemistry, and physics. Everything else pretty much falls into place if you have that kind of background.