Dr. Dong holds a Ph.D. in astrophysics from Princeton University (2013), and a B.S. in physics from Peking University (2008). After completing PhD he was awarded a NASA Hubble Fellowship at UC Berkeley/Lawrence Berkeley National Lab (2013-2016), and then a Bart J. Bok Fellowship at the University of Arizona (2016-2018) to carry out independent postdoctoral research. Dr. Dong started as an assistant professor at the University of Victoria in 2018. He was awarded a Sloan Research Fellowship in 2020.It is hard to see a plane cruising at 10 km during daytime, as the plane is tiny and faint on the sky. But, if we can see the contrail tailed behind the plane, we know where the plane is. Now, astronomers are applying the same principle to study how planets form, by detecting and charactering the structures baby planets produce in their birth cradles — protoplanetary disks. This is a new field largely driven by discoveries made by some of the largest and most advanced telescopes ever built. I will introduce the current status of the field, and highlight some of the latest developments as well as unsolved problems.