What are the planets made of, and how do we find out?

In the field of planetary science, we seek to understand how the planets formed and how they change over time. A key part of this understanding is finding out what the planets are made of, or more specifically, what is their elemental composition? In this talk, I will discuss a technique known as planetary nuclear spectroscopy. This technique uses gamma rays and neutrons to measure a planet’s elemental composition. I will first give an overview of the technique, and then take us on a tour of the solar system, stopping off at different planetary bodies where these measurements either have been or will be made. As part of this tour, I will discuss not only the measurements, but what is involved in building a space experiment and putting it into space.