The SSA-NEO system is based on syndicating and federating observation and tracking data provided by a large number of European and international sources. The key components include: Data on NEOs are collected from telescopes and radar systems worldwide. Each of these submit observations to the Minor Planet Center (MPC), operated by the International Astronomical Union (IAU) at Cambridge, Massachusetts, USA, which acts as a central clearing house for asteroid and comet observations. The measurements collected there are retrieved by the European Small Bodies Data Centre; orbits and miss distances are computed. In case of high-risk impact predictions, the data will be cross-checked with NASA's SENTRY system, operated by the Jet Propulsion Laboratory (JPL), California, before issuing alerts.