Kernel nulling: fundamental limitations and technological pathways from ground and space

Direct detection of young giant planets can probe formation processes near the snow line, which is thought to be where giant planet formation is most likely. I will outline the scientific requirements for observational constraints on this process, and show that the minimum requirements from the ground can be achieved by a high contrast VLTI instrument (Hi-5/VIKiNG) operating within the 2-5 micron range, nulling starlight in a highly calibratable manner with a "Kernel Nuller". Understanding these processes in more depth will eventually require an instrument more sensitive than is possible from the ground, requiring a cooled space mission. I will describe a pathway for such a mission.