PROGNOZ: the Table of Close Approaches and Collisions of Celestial Bodies with the Earth and the Moon
Terms of Using Information from the IAARAS website
The PROGNOZ program package maintains its catalogue of potentially hazardous asteroids (PHAs) which is based on the data published by the IAU Minor Planet Centre (MPC) and the new PHAs discoveries reported. For newly discovered PHAs, an independent determination of the orbital parameters and their errors is carried out, and for known PHAs it is refined from all observations of the objects. The asteroid motion is forecasted using the numerical integration method and taking into account perturbations and uncertainty in the current values of coordinates and velocities due to the uncertainty of initial conditions of the motion.
The shortest distance between two celestial bodies is calculated when the asteroid approaches the Earth or the Moon, and the probability of their collision is estimated using the flat target method. Geographical coordinates and their errors are calculated for the point where the celestial body may enter the atmosphere of the Earth, and topocentric parameters (azimuth and elevation) for the point of the possible collision.
The information which is obtained during the consecutive close approaches of asteroids with the Earth and the Moon forms a basis to construct the lines for the chronological table of approaches. It displays the most important information about each body and each event. The table includes the cases of the astronomical bodies to come up close to the Earth or/and the Moon within the period of the upcoming 90 days from the current moment and within 90 days before it. Each row of the table contains: 1) the number or name of the asteroid; 2) its probable diameter in meters; 3) the body being approached (the Earth or the Moon); 4) the moment of the shortest distance; 5) the shortest distance in the units which are equal to the average distance from the Earth to the Moon (384403 km); 6) relative velocity; 7) minimal orbital intersection distance (MOID) which is calculated from the osculating elements in the epoch close to the moment of the maximal approach; 8) probability of the collision; 9) energy in megatons; 10–11) probability of the collision according to the Palermo and Torino scales.
The rows are arranged in descending order so that the future convergence moments are at the top and the past cases are at the bottom.