Dr. Mark Hofstadter is a planetary scientist whose research focus is using radio telescopes to study the atmospheres of the giant planets, with a particular fondness for Uranus. He carries out observations both from the ground and from spacecraft. He is also involved in planning future missions to the outer solar system, in fostering international collaborations, and in educational activities. He served as the Principal Investigator for the MIRO instrument, which was a small radio telescope that flew on ESA's Rosetta mission to comet 67P. He received a Bachelor's degree in Physics from Stanford University and Master's and Ph.D. degrees in Planetary Science from Caltech. After working at JPL for more than 30 years, he retired in 2025 and became affiliated with SSI. Non-scientific hobbies include beach volleyball, skiing, and playing with dogs.