NASA Prepares Mars Orbiters And Rovers For Oct. 19 Flyby Of Comet Siding Spring

NASA is preparing its orbiters and rovers on Mars for an unprecedented encounter with a comet as the space projectile is expected to fly by the red planet on Oct. 19. The comet C/2013 A1, also known as Siding Spring, will pass within 87,000 miles of the Martian surface, which is less than half the distance between Earth and the moon.