Welcome to the world of Galileo as seen through the eyes of History 333's Spring 1995 Astronomy Group. The main goal of our group was to repeat Galileo's observations of the Moon and Jupiter's satellites as presented in his book Sidereus Nuncius, sunspots as presented in his Sunspot Letters, Venus as described in a letter to Benedetto Castelli, and of Saturn as announced in a letter to the Grand Duke's secretary. In order to replicate these observations we felt it necessary to create accurate replicas of a Galilean telescope and a simple mounting. In this way we might better be able to understand the difficulties and problems that Galileo might have faced while he was making these observations. We built a Galilean telescope and a mounting for each member of the group. Once these were built and we had stable apparati, we could begin our observations. We used a modified telescope for observations of sunspots and were able to produce some decent results observing the sun. However the weather was not very cooperative for our nighttime observations, and in fact we had very few clear nights in Houston after we had finished building the mountings (and without the mountings, observing is extremely difficult). In the spring in Houston we have many days and nights of clouds because the jet stream brings the weather systems out of the Pacific across Mexico and all along the Gulf Coast. So, we have had a very wet spring with very few moon- and cloud-free nights for observing. Because of the weather, time restrictions, and general observing problems associated with being in Houston, we were unable to do the extended observations that Galileo made of some of the heavenly bodies like Jupiter and Venus. However, we do have some observations and comments for all the heavenly bodies that Galileo observed. These include Jupiter, Venus, Orion and the Pleiades, the Moon, Mars, and Saturn. We have also included information and a list of resources on the net that may be useful for future projects on Galilean astronomy. So, explore our project to see what it was like for Galileo when he first made his astronomical observations. --Sandi Hassinger

Pick a planet and hold on:

Here is a list of times and dates for observing during the Spring of 1995.

We appreciate any comments or suggestions.