Comet C/2014 Q2, sequence of five time-lapse NEOWISE images. This long-period comet was discovered on 17 August 2014 by Terry Lovejoy. Comets are icy bodies from the outer solar system that boil and form a bright tail of gas and dust as they approach the Sun. Comet C/2014 Q2 reached its closest approach to the Sun on 30 January 2015. These images were obtained by NASA's NEOWISE (Near-Earth Object Wide-field Survey Explorer) mission in November 2013, when the comet was 1.7 astronomical units from the Sun. The red color is caused by the strong signal in the NEOWISE 4.6-micron (infrared) wavelength detector, owing to a combination of gas and dust in the comet's coma.