Monday, May 26, 2008

Phoenix Mars redux

Back in college, I took planetary geology from Peter Schultz. Peter is a crater man. We spent something like the first three weeks (two or three days per week) talking about impact craters. He was also a researcher at JPL/Ames, and he told us all about all the things he would shoot through the Ames Gun into a special bowl of whatever at whatever angle at whatever speed. Like: shooting an egg into sand at a ninety-degree angle verses a forty-five degree angle and examining the splatter. At that stage of my life, empirical research meant nothing to me: I was a historian who looked at people and political theory to see how ideas connected, almost like the study of intellectual gossip, and I didn't yet look at tangible objects and wonder how they got that way. And certainly the nuances of crater splatter were boring to me. I wanted to study the volcanos on Io (and did). I was interested in Mars and the possibility of water and weather. I wanted to learn more about the present before asking how it got that way.

Now it all seems so obvious, and perhaps I needed three weeks of crater study to get it: planets are made of things mashed together, and craters are the evidence of that. Duh. Just as when you look at light that comes from very distant objects, which takes many millions of light years to get here, you are actually looking back in time, unpeeling impact craters is also a way to look back in time.

Peter also taught me to turn the picture upside down if a crater in a photo looked like a bump to me.

Much as I found all that crater stuff somewhat irrelevant, the time was exactly right to be studying it, and to be studying it with Peter, and I'd like to believe I knew that. In 1980, Alvarez and Alvarez published the theory that the extinction of the dinosaurs was caused by a meteor impact. So impact crater theory was really hot stuff in the scheme of things. And this theory was very much in play. I thought it was a good one (having been raised on the theory of Nuclear Winter) and decided for myself that the meteor was what created Hudson Bay. What a privilege, a unique life experience, to study a theory before it became widely accepted. (The search since 1990 has been for the crater or crater patterns which caused the K-T Event. Hudson Bay is not in consideration.)

How many people remember an exam question from 25 years ago? I think the only one I remember was on Peter's final exam. He asked us how we would determine if Mars has or had water on it. I'm sure there were people in the class who wanted to use mass spectrometry or something to determine this from a distance, but my solution was to send a probe to one of the poles and reach out an arm or something and poke it. I suggested there might not be surface water, but there might be evidence of water below the surface.

So the Phoenix Mars project is particularly exciting to me.

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