Years later, when I went to college, I wanted to go into space myself, so I studied math and physics. Then I went to graduate school to study astrophysics and began doing research. It was 1973. I had just finished the research on my PhD degree at Cornell University. I was working with a scientist, Neil Brice, on a question about Saturn's moon Titan.
Titan is the only moon in the solar system with a thick atmosphere.
We wondered why Titan was special. We knew that some of Titan's atmosphere would leak off into space. Its gravity is not strong enough to hold the air tightly the way Earth's gravity does. I think that every scientist who had worked on Titan assumed that the situation was just like our own Moon. Our Moon's gravity is too weak to hold air molecules for very long.