Diagrams show how comet will approach Mars.

The Reconnaissance Orbiter captures images of Comet C/2013 A1, also known as Sliding Spring after the observatory which it, as it flies past on October 19th. The comet originated in the Oort , which is in the distant of our solar system.

These images were taken by the Orbiter’s High Imaging (HiRISE) camera while the comet flew approximately 86,000 miles from Mars at a of 35,700 miles per (57,400 km/h) relative to the .
Greg Giles