To study the formation and early development of planets around other stars (known as "exoplanets"), this program will measure the properties of infant exoplanets. Using new ways to make astronomical images at the world's largest and most sensitive infrared wavelength telescope--the Large Binocular Telescope at Mt. Graham, Arizona--this program will look at specific characteristics not studied by other scientific programs that image exoplanets. These planned observations can detect younger planets located very close to their host stars. The observations will constrain the processes that form giant planets, and will provide pictures of planets in their infancy. The Principal Investigator will incorporate the results into public lectures in Tucson and into teaching materials. University students will be involved with all aspects of the research. An unusual and highly beneficial aspect of the proposed work is the ability to probe simultaneously at high resolution exoplanets and the environments in which they are forming. The investigators will use non-redundant masking interferometry coupled with adaptive optics on the telescope, which allows observations close to or within the diffraction limit of their telescope system. Non-redundant masking provides high precision measurements, and when used behind an adaptive optics system, can reach faint targets and companions with contrast. This will provide information on the boundary conditions for planet formation, including initial composition, while at the same time constrain how planets are assembled. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.