FollowingChesley and Spahr (2004)we concentrate on the subset of PHOs that are in fact destined for a collision with the Earth.
They showed that long before impact the impactors’ steady state
sky-plane distribution is concentrated on the ecliptic and at small
solar elongation. We extend their analysis and find that the skyplane distribution of impactors has interesting and potentially useful structure in the time leading to collision. We also study the
capabilities of one next-generation survey (PS1) at identifying
the impactors well before collision. In particular, we will answer
the following questions: How different are the orbital characteristics of the impactor population and current NEO and PHO models?
What is the survey efficiency for identifying asteroids on a collision
course with the Earth as a function of their diameter? How much
warning time will be provided before the impact? How accurate
is the orbital solution prior to impact? How does the MOID
2
evolve
in time and is the current definition of a PHO consistent with flagging dangerous objects? What are the orbital properties of objects
that are not found? Are there methods to improve the efficiency of
identifying impactors?