Comet Hartley 2, designated as 103P/Hartley is a small periodic comet with an orbital period of 6.46 years.  It was discovered by Malcom Hartley in 1986 at the Schmidt Telescope Unit in Siding Spring, Australia.  Its diameter is estimated to be 1.2 to 1.6 kilometres (0.75 to 0.99 mi).

Hartley 2 was the target of a flyby of the Deep Impact spacecraft, as part of the EPOXI mission, on November 4, 2010, which was able to approach within 700 kilometers (430 mi) of Hartley 2 as part of its extended mission.  As of November 2010, Hartley 2 is the smallest comet to have been visited by spacecraft.

http://en.wikipedia.org/wiki/103P/Hartley

 

ABOUT THE IMAGE

DATE/TIME: Oct. 6th, 2010. App 10:00pm.

CAMERA: Canon 450D

LENS: Canon 50mm F/2.8

ISO: 1600

EXPOSURES: 42

EXPOSURE LENGTH: 100sec.

TOTAL EXPOSURE: 1hr, 10min.