An Early Look of Comet C/2013 A1 (Siding Spring): Breathtaker or Nightmare?

Quan-Zhi Ye, Man-To Hui

The dynamically new comet, C/2013 A1 (Siding Spring), is to make a close approach to Mars on 2014 October 19 at 18:30 UT at a distance of 40+/-1 Martian radius. Such extremely rare…