After nine years and a journey of nearly 5 billion kilometers, an American probe has awoke from hibernation to begin a mission to study the icy dwarf planet Pluto.
A preset alarm clock roused NASA's New Horizons from its electronic slumber on December 6.
The observation of Pluto, which has a diameter of just 2,000 kilometers, its moons, and other bodies in the solar system's frozen backyard is to begin in January.
Pluto lies in the Kuiper Belt, a region of mini-planets orbiting the sun beyond Neptune that are believed to be leftover remains from the formation of the solar system some 4.6 billion years ago.
In 2006, Pluto was stripped of its title as the ninth planet in the solar system, becoming a dwarf planet.
