Probe's 9-year journey to Pluto
An American spacecraft almost three billion miles from Earth will today get a close up look at the last truly unexplored world in the solar system.
New Horizons has taken more than nine years to reach Pluto, carrying with it the ashes of the astronomer who discovered the remote icy object in 1930.
Seven months into the probe's epic journey, international astronomers down-graded Pluto's status to "dwarf planet".
Pluto is two-thirds the size of the Earth's moon.