ASTR 111 The Solar System and Its Origin
Fall 2025

Observing Project

Project description
Analysis due November 22
Reports due December 14

Using the 24-inch telescope and CCD camera at the Mees Observatory, you will observe Saturn and Neptune and their moons in order to measure the mass of these planets and validate Newton's law of gravity and Kepler's third law. All raw data can be found below. Please consult the shared Google spreadsheet for the processed data.

This is the

magic astro secret!

Reduced data

Data workbook

Enter your measured positions of the moons into the workbook above. The observed time should be in 24 hours (ET), and the positions are given in units of pixels.

Some observations will have multiple measurements (completed by different members of the group). Feel free to use the average, or any of the numbers individually, for your analysis. You can also use the different measurements to get a better estimate for the uncertainty.