(Corrected paper title list in e-mail.) Cometary Science Newsletter Issue 4 July 2015 http://www.cometarysciencenews.org/ - A Martian Meteor Shower from Comet C/2013 A1 (Siding Spring) - The Closest Approach of Comet 252P/LINEAR 12 to Earth - Refereed Journal Papers + Prompt Emission by OH in Comet Hyakutake + Measurements of the Near-Nucleus Coma of Comet 67P/Churyumov-Gerasimenko with the Alice Far-Ultraviolet Spectrograph on Rosetta + Comet 67P/Churyumov-Gerasimenko: Constraints on Its Origin from OSIRIS Observations + Spectrophotometric Properties of the Nucleus of Comet 67P/Churyumov-Gerasimenko from the OSIRIS Instrument Onboard the ROSETTA Spacecraft + A New Analysis of Spitzer Observations of Comet 29P/Schwassmann-Wachmann 1 + MAVEN IUVS Observations of the Aftermath of the Comet Siding Spring Meteor Shower on Mars + An Ionized Layer in the Upper Atmosphere of Mars Caused by Dust Impacts from Comet Siding Spring + Metallic Ions in the Upper Atmosphere of Mars from the Passage of Comet C/2013 A1 (Siding Spring) + Effects of the Passage of Comet C/2013 A1 (Siding Spring) Observed by the Shallow Radar (SHARAD) on Mars Reconnaissance Orbiter + High-Resolution Spectra of Comet C/2013 R1 (Lovejoy) + Sublimation-Induced Orbital Perturbations of Extrasolar Active Asteroids and Comets: Application to White Dwarf Systems -- The Cometary Science Newsletter is dedicated to sharing and furthering cometary science. CSN invites contributions from the astronomical and planetary science communities, including abstracts of papers accepted for publication in refereed journals, thesis abstracts, timely notes on particular comets, conference announcements, job announcements, or other relevant and brief scientific communications. Relevant topics include observational, theoretical, and laboratory work concerning comets, but also may include studies of associated phenomena, such as Centaurs, asteroid-comet transition objects, debris disks, and protoplanetary disks.