The first colour movies from NASA's New Horizons mission show Pluto and its largest moon Charon and the complex orbital dance of the two bodies, known as a double planet.
"It's exciting to see Pluto and Charon in motion and in colour," said New Horizons principal examiner Alan Stern of the Southwest Research Institute (SwRI) at Boulder, Colorado.
"Even at this low resolution, we can see that Pluto and Charon have different colours -- Pluto is beige-orange, while Charon is grey. Exactly why they are so different is the subject of debate," Stern said.
New Horizons will be at the closest to Pluto on July 14, zipping by about 12,500 km above the surface.
It is the first mission to Pluto and the Kuiper Belt, a relic of solar system formation beyond Neptune.
Sending a spacecraft on this almost three billion-mile journey will help astronomers answer basic questions about the surface properties, atmospheres and moons of the Pluto system.
These near-true colour movies were assembled from images made in three colours -- blue, red and near-infrared - by the multi-colour visible imaging camera on the instrument known as Ralph, inspired from "The Honeymooners", the classic American sitcom.
The images were taken on nine different occasions from May 29 to June 3.
Although the two movies were prepared from the same images, they display the Pluto-Charon pair from different perspectives.
One movie is "Pluto-centric", meaning that Charon is shown as it moves in relation to Pluto, which is digitally centred in the movie.
Pluto makes one turn around its axis every 6 days, 9 hours and 17.6 minutes -- the same length of time that Charon rotates on its orbit.
"Colour observations are going to get much, much better, eventually resolving the surfaces of Charon and Pluto at scales of just kms," said Cathy Olkin, New Horizons deputy project scientist from SwRI.
"This will help us unravel the nature of their surfaces and the way volatiles transport around their surfaces. I can not wait; it is just a few weeks away."
