NOVA; To the Moon; Interview with Ralph Baldwin, planetary scientist, part 1 of 3

How did you get started in astronomy? In astronomy? I had a grandmother and she was a magnificent woman, learned former school teacher and she used to take her young grandson out and point out the stars to him. She was no astronomer but she knew her constellations and she knew the names of the bright stars and I began to find out it was interesting. Then you tell us about your studying astronomy or you went into graduate work in astronomy? I knew even before I left high school that I wanted to be an astronomer. I went to the University of Michigan. It was there from 1930 to 1937 or it took my PhD.

Did you study much about the moon during your work there? Lord no, no reputable astronomer wanted to have anything to do with the moon in those days. It just got in the way of something that was more important. So what were you looking at? My thesis was on a NOVA, NOVA's Cygnia number three of 1920 and it was difficult but I came up with a good solution. Let's jump forward to 1941, you're teaching at Adler Planetarium? No. In 1941 I was an instructor. I was at the Derbenen Observatory of Northwestern University. My wife was pregnant. We needed more money. So I took a job, fortunately offered by Maude Bennett, a lecturing at the Adler Planetarium. Well on the walls outside of the Planetarium chamber were large numbers of astronomical

photographs, transparencies and about six of them were of the moon. Well as I've just said, the moon didn't really interest me but those are beautiful pictures and so I watched them. And suddenly one day I began to see some features there that I couldn't explain. There were valleys with raised edges. The farther the bad valley was toward the north, I'm sorry, toward the south, the narrower it was. The only place I could find any possible explanation of them was in a 1919 paper by an English astronomer named Stevenson who said that he thought that those valleys were produced by the tangential impact of large swarm of meteorites. Well that was geometrically impossible because they were scattered over a big part of the moon's surface.

And I suddenly realized one day that if you projected the line of each valley back in one direction along the arc of a great circle that they all intersected in the central region of a huge round structure called Maury Embryum. Those valleys, I then began to realize, had been made by something almost impossibly violent that happened in explosion in the center of that Maury Embryum and it sent material broadcasts and where it hit the surface of the moon and it worked more on the high spots than the low. The gouged out the valleys. Well, Galileo had said that the creators of the moon were volcanic. Well, I couldn't picture any volcano with enough power to make those valleys to eject

that amount of material. How big did you reckon those valleys and craters were just by looking at the transparencies? Well they usually were ten times as long as they were wide and in length they ranged from three or four kilometers to maybe thirty kilometers. They were good sized valleys. So I meant big hunks of material had been thrown hundreds and hundreds of kilometers in many cases. Well, the next logical step was if it was not a volcano, what could it have been? Well, the only source of energy that I could conceive of, still the only one I could conceive of, is that carried by large meteorites or asteroid-like bodies. If one of those had come in and formed this great basin because the lava, the dark material proved to be lava frozen and it was surrounded by a mountainous rim.

If that rim meant that this was the largest crater on the front face of the moon, twelve hundred kilometers across, the body that hit must have been something of the art of approaching a hundred kilometers in diameter. The object that we now know, struck down in Yucatan, killed off the dinosaurs, was about six miles, six kilometers in diameter. This was ten times that or a thousand times more mass. That would have enough energy to produce it. Well, I went back to the observatory, told the boss man there, Dr. Oliver J. Lee, that I thought I had a new major discovery about the moon, nearly left at me.

He said, Ralph, that doesn't jive with the program of the observatory. About three days later, I began to realize, hey, he didn't say I couldn't work on it. He just said the program didn't jive. So I started working collecting all the information I could and then a few days after that, Lee, Dave Hamlin and I drove to Yurkey's observatory for one of their symposium. And while there I told Otto Struvy, the head of Yurkey's, about this embryo idea, and Otto said, Ralph, you're giving the next symposium up here. That made it all right with Lee. So we got along famously there. Well, a month later, I went back and I presented what I felt and still feel was a very good program with arguments that I didn't feel anybody could hear and fail to realize their truth.

And I didn't convert a single one of those world famous astronomers. And there were plenty of them there, people whose names were known all over the world. Well, that was a big disappointment. But my next biggest disappointment came when I tried to put in print what I had said. And it was turned down by three prominent publications. It was finally taken by the Popular Astronomy magazine up in Minnesota. And a year later, I went through the same routine. That first paper came out in 1942. In 1943, I went through the same routine on a second and more elaborate paper, the same general subject. And I had to publish that in Popular Astronomy also. So no science journal, academic journal saying what was going to touch this, your theory?

I went to the more prominent ones, but yes, I'd have to say so. Can you tell us that in terms of a complete sense that the science journals would not take the paper? Which ones? Or just tell us the science journals or name them or you don't have to name them. Well, I offered the paper to three of the prominent science journals. Not one of them would touch it. For that reason, I went to Popular Astronomy and that became more popular with me right away. What was the reaction to the Popular Astronomy articles when they came out both in and out of the field? I don't know because I never heard any.

I was coming to realize that basically I was preaching heresy way back in 1610, about 350 years before. Galileo turned his little optic tube about so long the lens about that big on the moon and he saw these round structures and he called them craters. But the only craters those people knew were volcanic craters. Galileo said they were volcanoes, volcanoes, therefore they were. And over the centuries that became dogba, everybody accepted it. Astronomers and geologists were not interested in the moon. They wouldn't pay any attention because they didn't feel it was worthwhile. At least that's my interpretation. I began to realize that my opponents were not the modern scientists.

My opponent was Galileo. And here's this little instructor still less than 30 years old trying to take on the world famous Galileo. I began to realize that if I were going to make any progress, I was going to have to publish a full book size work on the moon and present the data as accurately and as thoroughly as possible. That book came out in 1940.