Collaborating with his advisor to capture sharp images of planetary systems from Chile’s Atacama Desert is a highlight in Ya-Lin Wu’s graduate student experience. Ya-Lin’s work centers on observations of young planets, with a specific interest in the ways these planets acquire and shape moons in their vicinity. Using the powerful Atacama Large Millimeter/submillimeter Array (ALMA) telescope, he conducted a systemic study to image the vestigial gas and dust surrounding young gas giants—what astronomers call circumplanetary disks. Obtaining visuals of circumplanetary disks is paramount to understanding the early conditions of moons, and offers a bridge to deeper knowledge of natural satellites in our own solar system.

In his fellowship, Ya-Lin will lead studies to probe the physical properties and composition of circumplanetary disks and reveal how they influence the evolution of planets and moons. These efforts can lay important groundwork for the budding area of exomoon study, providing an observational underpinning to guide future theoretical examination of this topic. Ya-Lin graduated from the University of Arizona in May 2018 with a Ph.D. in astronomy and astrophysics.

“We have discovered thousands of exoplanets, but not a single exomoon. They are very difficult to detect with current technology, so a way around that is to study circumplanetary disks around planets to learn about the initial conditions of moon formation. This will tell us in turn how planets accrete their mass and grow over time.”