Tracking and Impact Prediction of Earth-Crossing-Objects (ECOs) on a Collision Course with Earth

This study investigated the effectiveness of Earth-based angles only observations in determining the orbit of various hypothetical Earth-Crossing-Objects (ECOs). \u27True\u27 trajectories were simulated specifically for Earth-Crossing- Comets (ECCs) by numerically integrating in a Restricted Three Body system. Starting at Earth impact points, the state vectors were reverse-propagated to a proposed detection time. Observations (obs), with state-of-the-art accuracy, were then simulated with error induced by a Gaussian random number generator; these were used in a least- squares differential corrector to estimate the positions of the ECOs. State vectors and covariance matrices were then propagated to the impact times and axis lengths of the one sigma impact footprint were calculated. Varied amounts of data were fed into the differential corrector and it was determined that Earth-based obs alone may be ineffective in predicting an ECC\u27s orbit