When new observations of an NEO are made, they are submitted to the Minor Planet Centre (MPC) in Massachusetts in the USA. The MPC acts as a clearing house for all new observations. These approved observations are then distributed to the scientific community.

There are two independent centres that use these observations to calculate the risk of any future impacts. One is based in the USA the other in Italy.

In the USA this work is carried out by the Jet Propulsion Laboratory’s Sentry System. Sentry is a highly automated collision monitoring system that continually scans the most current asteroid catalogue for possibilities of future impact with Earth over the next 100 years.

In Italy, the work is carried out by NEODyS, which is based on a continually and (almost) automatically maintained database of near-Earth asteroid orbits. Use the links above to view the output of both systems.