Note about the impact possibilities of asteroid (99942) Apophis

Abstract

The Monte Carlo method of the nominal orbit clonning was applied to the case of 99942 Apophis, the asteroid from the Aten group. Calculations based on observations from the time interval of 2004 03 15 - 2008 01 09 have shown that the asteroid will pass near Earth in 2029 at the minimum distance of 5.921 \pm 0.042 R_{Earth}, what implies that the likelihood that Apophis strikes the planet at 2036 April 13 increased to 4.5\times 10^{-6} (from about 6\times 10^{-7} previously announced by us in Paper~I (Krolikowska, Sitarski and Soltan, 2009, MNRAS 399, 1964). This value is identical with that given by Chesley, Baer, and Monet (2010, Icarus, in press).