Nasa's New Horizons probe in final countdown to Pluto flyby

Next Tuesday, more than nine years after leaving Earth, Nasa's probe will make history as the first spacecraft ever to reach the distant dwarf planet

Nine years after it left Earth, Nasa's New Horizons spacecraft will on Tuesday become the first probe to reach Pluto, the mysterious icy world at the edge of the solar system, snapping photographs as it hurtles by at 30,000 miles an hour.

The journey has taken sufficiently long that in the intervening years the status of the celestial body has been downgraded by astronomers from planet to the less impressive-sounding dwarf planet.