Born in July 1963 in South Vietnam, I am the second child in a family of four children (one older sister, two younger brothers). We were part of a much larger family: my father had fourteen siblings, my mother five. Both my parents had emigrated to South Vietnam from North Vietnam in 1955. My father taught me French as a child, initiating a fondness for languages. In April 1975, when the South Vietnamese government collapsed, my family emigrated to the United States. We spent the next several months in a series of refugee camps, rented rooms and motel rooms before settling in Paducah, Kentucky, living with an aunt and her family. My father remained in Southern California to learn a trade and find employment, believing it easier to do this without supporting a family at the same time. Our year in Kentucky was a happy one, as my siblings and I were warmly welcomed by our teachers and fellow students. In the summer of 1976, we relocated to Ventura, California, to join my father, who by that time had become a bookkeeper. My family still remains in Southern California, where we have been joined by many cousins, aunts and uncles. Other relatives are spread out across the United States and beyond (Canada, France and Hong Kong).
The high school years in Ventura went well and I enrolled at Stanford University in 1980 as a freshman. I obtained a bachelor’s degree in Physics from Stanford in 1984. A subsequent short stint at the Jet Propulsion Laboratory introduced me to planetary astronomy: the remarkable images returned by the Voyager spacecraft, opened my eyes to the prospect of studying such exotic objects as a profession.  After a summer in Nepal and Tibet in 1986, I enrolled as a graduate student in the Department of Earth, Atmospheric, and Planetary Science at the Massachusetts Institute of Technology (MIT).  There, I started working with David Jewitt, who was my advisor at the time; this was the start of our longtime collaboration.
I had the most wonderful time in graduate school (1986 – 1990): I was free to pursue any subject that struck my interest, essentially without any other concern. David and I collaborated on many projects focusing on physical properties of the small primitive bodies of the solar system: comets, asteroids, satellites of the outer planets. In 1987, we started our survey of the outer solar system, wishing to confirm that the outer solar system was truly as empty as it seemed. This work was to occupy us for the next twenty years, although my doctoral thesis was on the relationship between comets and asteroids.  David left MIT in 1988 to take a professorship at the University of Hawaii in Manoa; I also moved to Hawaii in order to continue working with David, while remaining a graduate student at MIT. I received my Ph.D. in 1990.
In the fall of 1990, I left Hawaii to be a Harvard-Smithsonian Postdoctoral Fellow at the Center for Astrophysics in Cambridge, Massachusetts. On 30 August 1992, using the University of Hawaii’s 2.2-meter telescope on Mauna Kea, David and I discovered the object 1992 QB1, the first acknowledged representative of the Kuiper Belt, a large band of primitive bodies beyond Neptune. Before it received its official title (15760) 1992 QB1, we nicknamed our newly found object “Smiley” after the shrewdly intelligent British spymaster George Smiley in John Le Carre’s spy novels (I think Smiley would approve). The 1992 – 1993 academic year was spent at UC Berkeley as a Hubble Fellow, followed by a year at Stanford. In the fall of 1994, I joined the faculty at Harvard University as a professor in the Astronomy Department. This was followed by a faculty position at the University of Leiden in the Netherlands from 1998 to 2001.  
Upon returning to the United States in the fall of 2001, I started working on instrumentation as Technical Staff at the MIT Lincoln Laboratory in Lexington, Massachusetts. This change of direction from traditional science was prompted by a desire to learn how to build instruments: I had always felt that my education was lacking in this area, and I very much wanted to learn how to make things work. At Lincoln Laboratory, I developed an interest in the coherent properties of light and how to make use of them.
Besides my research activities, I have served on several scientific committees, including NASA’s Origin of the Solar System Committee, various telescope time allocation committees, and most recently, the National Academy of Sciences’ Planetary Science Decadal Survey for 2013 – 2022.
In my personal life, I am married to Ronnie Hoogerwerf, whom I met at Leiden. We live with our six-year-old daughter Eliot, and Mango, a Newfoundland dog, in Lexington, Massachusetts, where we are kept busy by a vegetable garden and a very popular bird feeder.

17 September 2012