NASA probe nears end of pioneering mission to Pluto after nine-year journey

A spacecraft headed for Pluto is nearing its destination after a nine-year mission to travel the three billion miles from Earth to the outer reaches of the Solar System.

NASA scientists hope the New Horizons probe, which awoke from its long hibernation at the beginning of Devember, will open up "an entire region of new worlds" as it observes the behaviour of Pluto and its neighbouring objects.

The craft will begin its observations on January 15, with its closest encounter to Pluto scheduled for July 14.

It will then beam back images of Pluto and its moons for study and analysis, with its proximity enabling it to capture footage of a much higher quality than any obtained by the Hubble Space Telescope.

One of the project's scientists, applied physicist Dr Hal Weaver, of John Hopkins University in the US, said the team was excited to discover what the probe might find.

Since its launch on January 19, 2006, New Horizons has spent a total of 1,873 days - around two-thirds of its flight time - in hibernation to reduce the chance of system failures, and to prevent wear and tear on electrical systems.

Its equipment includes specialised cameras, advanced spectrometers to analyse the chemical composition of light signals, and a space dust detector.

Discovered in 1930, Pluto was originally thought of as the ninth planet in the Solar System, residing an average of 3.67 billion miles from the Sun, but was reclassified in 2006.

It is now considered a "dwarf planet" - one of a number of icy bodies known as the Kuiper Belt, beyond "true" planets such as Earth and Mars.

The Kuiper Belt is one of the last remaining unexplored regions of the Solar System, along with the Oort Cloud - another band of icy objects even further away.

Both belts are thought to be the source of comets.