The Threat to Earth from Asteroids and Comets - Pan-STARRS public pages.
Pan-STARRS and the NEO threat - Pan-STARRS public pages.
GIF animation of inner solar system objects (5.6MB).
Pan-STARRS goal is to extend the search for PHAs from km scales (where current surveys are approaching completeness) down to 300m scales. It is estimated that there is approximately a 1 in 700 chance that such an object will collide with Earth within a century. Such an object would deliver an energy roughly equivalent to 1000 MT of TNT.
Orbital elements are known for only a small fraction of such objects, and none of these actually pose a threat, but the rest pose a real hazard. If Pan-STARRS can detect and catalog most of these objects, and show that their orbits are not hazardous then that hazard will have been eliminated.
Detailed simulations have been performed to establish the rate at which Pan-STARRS can detect PHAs and eliminate collision risk.
The starting point is a model for the distribution of orbital elements for asteroids that has been developed by Rob Jebicke and colleagues. Artificial samples of objects can be drawn from this distribution, assigned an appropriate risk factor, and their orbits propagated forward in time to determine their observability by Pan-STARRS.
Simulations.20021205.pdf - Rob Jedicke presentation describing Pan-STARRS and other NEO searches and simulated completeness.
GIF animation (2.3MB) of the view of 300m scale PHAs from the Earth over a period of several years. Objects that are detectable are yellow - objects beyond the reach of the survey are blue.
Performance of NEO Surveys for Reducing Asteroid Collision Risk (Kaiser) describes the methodology used to assign risk and to compute observability, and shows the completeness, as a function of time for Pan-STARRS and other systems for a variety of impactor energy.
Asteroid Detection (Kaiser) reviews the definition of H-magnitudes and phase and distance effects on observability. Trailing losses are estimated and detection rates are plotted.