We show that the estimates of close encounter of this comet with Mars depend on data treatment .
Using the data taken in the two-year period , we derived that the comet will miss Mars on 2014 October 19 at the distance of about 140 150 \pm 55 km or 140 300 \pm 45 km from its center , depending on the method of data processing in the purely gravitational model of motion ( based on non-weighted data or weighted data , respectively ) .
Unfortunately , the non-gravitational model of motion is still very uncertain , thus we can only speculate about estimates of expected distances for non-gravitational orbital solutions .
However , we did not obtain a significant differences in close encounter prediction between the non-gravitational solutions and the gravitational ones .