Information on Galileo Discovering Saturn


My name is Eric Loberg. I'm the director of the Taylor Planetarium at The Museum of the Rockies and I was going to talk about Galileo discovering Saturn. Galileo actually did not discover Saturn, Saturn is a very old planet and it's been known as long as people have been around that we know of. It's an ancient planet, the Babylonians almost certainly knew about it and they did a lot of astrology. They would watch the planets move. Planet actually means wanderer and it was something that moved along the star field in ancient times and still today and you can watch this today. You can take Saturn and watch it any given night with its rings and it will slowly move, one night here and the next night here and it will slowly move along this path, night after night after night and if you watch it, all the stars will sit exactly still. Well Saturn moves along that path. So the ancients knew about this. What Galileo did discover is the rings around Saturn. He was probably the first to put a telescope up to Saturn and he saw those rings with his telescope. It was a 4X telescope, not much better than your binoculars today. He then made himself an eight times magnification telescope and looked up there and he saw these rings going back and forth. We can look at Saturn today and its tilt as it goes around the sun. Saturn is tilted about like Earth is. Earth is 23 and 1/2 degrees as its North Pole is pointed towards the North Star as it goes around the sun. Saturn is about the same, about 27 degrees and so Saturn tilts as it goes around the sun. You can use that like a Frisbee here and watch what we see, Saturn. Saturn slowly opens and tilts north and then south and what we'll see is the Frisbee north and south and occasionally you'll see the Saturn or the Frisbee here with the rings edge on. It's much harder to see that from space. That really confused Galileo. Galileo thought when it was tilted down he saw these bulges. Originally he called them ears and then he thought he had discovered moons. Then they disappear on him and it went exactly edge on and he couldn't see anything with the smaller telescope and he wondered why. It took many more years for Christiaan Huygens to come after Galileo and figure out that this was actually a ring system that was going around Saturn. Why we can't see Saturn's rings very well from Earth is it's so so far away. Saturn is our second biggest planet. You can stack about nine and a half Earths across Saturn's face. So what did Galileo discover? Not Saturn but Saturn's rings with the small telescope. I'm Eric Loberg with The Museum of the Rockies Taylor Planetarium.

J. Eric Loberg is the manager, lecturer, and program planner at the Taylor Planetarium at the World, a renowned museum of the Rockies in Bozeman, Montana.