The Long Range Reconnaissance Imager (LORRI) on New Horizons acquired
images of the Pluto field three days apart in late September 2006, in
order to see Pluto's motion against a dense background of stars. LORRI
took three frames at 1-second exposures on both Sept. 21 and Sept. 24.
Because it moved along its predicted path, Pluto was detected in all six
images.
These images are displayed using false-color to represent different
intensities: the lowest intensity level is black, different shades of red
mark intermediate intensities, and the highest intensity is white.
The images appear pixilated because they were obtained in a mode that
compensates for the drift in spacecraft pointing over long exposure times.
LORRI also made these observations before operators uploaded new
flight-control software in October; the upgraded software package includes
an optical navigation capability that will make LORRI approximately three
times more sensitive still than for these Pluto observations.
Photojournal Note: There is debate within the science community as to whether Pluto should be classified as a Planet or a dwarf planet.