海王星外自動掩星普查計劃是利用掩星現象來量測海王星外天體之大小分布。利用位於墨西哥OAN天文台的三台自動化望遠鏡及能高速連拍的相機，進行長時間觀測以捕捉0.2秒的掩星現象，取得太陽系形成及動力學演化上的線索。
The Transneptunian Automated Occultation Survey (TAOS II) aims to measure the size distribution of small Trans-Neptunian Objects (TNOs) with diameters ranging from 300 meters to 30 kilometers. Located at the Observatorio Astronomico Nacional (OAN) in San Pedro Mártir (SPM), Mexico, TAOS II features three 1.3-meter robotic telescopes and high-speed, wide-field cameras operating at 20Hz. Its mission is to simultaneously monitor approximately 10,000 stars, capturing occultation events, each lasting about 200 milliseconds, generated by these small TNOs. Investigating the TNO size distribution is scientifically significant as it provides crucial insights into the formation and dynamic evolution of the Solar System.