TAOS II, the Transneptunian Automated Occultation Survey, will measure the size distribution of small (~1 km diameter) Trans-Neptunian Objects (TNOs) . The TNO size distribution is of scientific interest because it provides important information on the formation and dynamical evolution of the Solar System. Furthermore, TNOs are thought to be the source population for the short period comets, and an accurate census of these small objects can help us understand the mechanism by which TNOs are perturbed into cometary orbits. Such objects are impossible to detect directly because they are too faint to be seen with even the largest telescopes. However, when such an object passes in front of a star, the star will "blink out" for a small fraction of a second. The detection and characterization of these occultation events are the primary science goals of this survey.

The TAOS II survey will operate three medium sized telescopes at the Observatorio Astronomico Nacional (OAN) at San Pedro Mártir (SPM) in Baja California, México. Each telescope will be equipped with a custom high-speed camera capable of collecting image data on more than 10,000 stars at a readout cadence of 20 Hz. The resulting data volume will be enormous, with nearly a petabyte per year of raw image and lightcurve data.