Thousands of exoplanets have been discovered over the past few years. These discoveries were enabled by large and homogeneous space-based time domain surveys of nearby stars, including NASA's Kepler Mission. To push the exoplanet detection threshold to the smallest planets or the longest orbital periods using these data, we combine physical models of exoplanets with data-driven models of the stars and the spacecraft. Scaling these models to be applied to hundreds of thousands of stars with tens of thousands of measurements each poses an interesting technical challenge that we have solved in close interdisciplinary collaboration. In this talk, I will describe the current and future datasets, and the basic problem of exoplanet detection. I will go on to outline the technical challenges and present some of our solutions. Finally, I will discuss how we understand the place of our Solar System in the greater context of the population of planets using these discoveries.

With the discoveries of thousands of exoplanets over the last decade from both ground telescopes and space, the field of exoplanet science has been revolutionized. We now know that exoplanets are common, that small planets far outnumber large ones, and that solar systems come in a myriad of forms. The next revolution will come with the advent of direct imaging of exoplanets from space. This will make accessible planets down to Earth size and will provide information on the chemical makeup of the planets and their atmospheres. Within the next 15 years we may for the first time image an earth and search for evidence of life. This new era will begin with the launch of NASA's WFIRST spacecraft in 2025, the first telescope with a high performance coronagraph enabling imaging of planets down to 2 earth radii and capable of taking spectra of their atmosphere. In this talk I will describe the basics of high-contrast imaging and the key technologies developed over the last decade that make it possible. In particular, I describe the 15 year effort at Princeton on coronagraphs, wavefront control, and starshades that began and succeeded because of the close partnership between engineering and astrophysics.

View Dr. Kasdin’s TED Talk, “The flower-shaped starshade that might help us detect Earth-like planets.”

The first direct detections of gravitational waves in late 2015 were made possible by a forty year experimental campaign to design, build, and operate LIGO, the Laser Interferometer Gravitational-wave Observatory. In this colloquium, I’ll cover gravitational waves and what makes them so difficult to detect and at the same time such powerful and unique probes of the universe. I’ll also give a flavor of the somewhat complicated history of how LIGO was conceived and built. Most of the presentation will focus on the interferometers, the LIGO detections and their astrophysical implications. Time permitting, I’ll give a preview of where LIGO intends to go in the next decade and beyond.