Cometary Science Newsletter Issue 2 May 2015 http://www.cometarysciencenews.org/ - Editor's Note - CHagall: A Discovery Mission Proposal - Refereed Journal Papers + Short-Term Variability of Comet C/2012 S1 (ISON) at 4.8 AU From the Sun + Density and Charge of Pristine Fluffy Particles From Comet 67P/Churyumov-Gerasimenko + Imaging Polarimetry of Comet C/2013 V1 (Boattini) and Comet 290P/Jager Before and After Perihelion + Crater-Diameter Distribution on Comets 9P and 81P and Potential Meteoroid Streams Crossing Their Orbits + Comets as Collisional Fragments of a Primordial Planetesimal Disk - PhD Dissertations + Spectrophotometric Analysis of Cometary Nuclei From In Situ Observations