The comet 2013 A1 will make a close approach to Mars next year on Oct. 19, 2014. You can check the details of the close approach for a location on Mars using JPL's HORIZONS Web-Interface with the following settings as inputs.
The minimum distance from the given location is 0.0007764 AU at 18:43 UT. To display the data in a polar plot one needs to Altitude and Declination into the corresponding Polar Angle. For the local horizon plot the Polar Angle is the angle from zenith.