Greg Anderson

What are your research interests?

I’m a planetary astronomer, and my primary interests are in the rings and small satellites of Saturn.

Where were you before Beloit?

I was working on my Ph.D. degree at Cornell University and teaching at Ithaca College in the physics department.

What attracted you to astronomy?

I’ve been interested in astronomy since I was a little kid. I remember two books that were a big influence on me when I was about 9 years-old. One was Charlie Brown’s Book of Questions and Answers about the Earth and Space, with Peanuts characters in a Q & A format.

I remember reading that book over and over. My uncle also bought me a book called Astronomy Today, which was just a basic elementary school kid’s introduction to astronomy. I just couldn’t put it down.

I also read a lot of science fiction as a young person, and it warped my mind. So I pretty much always wanted to do astronomy. As an undergraduate, I realized that I had been looking at distant galaxies, and pulsars, and stars, and what really excited me about science fiction was the idea of traveling around in our solar system and discovering new things. When I went to graduate school and looked into all the different projects professors were working on, I found I was most interested in the rings of Saturn.

What aspect of Saturn’s rings are you focused on?

The rings of Saturn are made up of chunks of ice, most of them about the size of softballs, that orbit around the planet. There is an important balance between the gravity between these chunks, which tends to make them clump together, and the tidal forces caused by the gravity of Saturn, which tend to pull them apart. This idea is becoming a key concept in understanding not only how the rings behave but also how planets form around stars.

I’ve studied the rings both from a dynamical point of view, which is how they move and the influence of Saturn’s gravity and the other moons and the sun, and from a photometric point of view, which measures the strength of the light that we get, the brightness of the satellites, and the rings under different circumstances. Within that general area, most of my work has been on the F ring of Saturn, the one that lies outside the bright rings that everybody has seen in pictures.

Why the F ring?

The F ring becomes important when you look at the rings edge on. It’s slightly thicker than the others and this blocks some of the light from the main rings. It also has a tilt, so it lets through more light on the east side of the rings, say, than the west side. I used this tilt to determine how thick the F ring is (6 to 20 kilometers), the first measurement ever made of the physical vertical thickness of the F ring.

What do you like about Beloit?

The focus is on teaching at Beloit. Our students have a playful attitude about learning, and it’s driven by their own intellectual curiosity. It’s liberating to be able to throw anything at them, and they want to engage in it. Plus, Beloit faculty embrace a spirit of mentorship that is very supportive for young faculty members.

What’s up next for you?

As we get ready to close Chamberlin Hall, I’m responsible for overseeing the move of the large telescope (my baby) from the Thompson Observatory. It will go into storage and eventually be installed at a new, dark location outside the city of Beloit.

My students are also beginning to collaborate with me on my work with Saturn’s rings. This semester, they’re working on images of the rings and information about Saturn’s moons recently captured by the Cassini spacecraft.

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