In the last half hour, a spacecraft has flown within just seven and a half thousand miles of the surface of Pluto. New horizons has taken more than nine years to reach the dwarf planet, which lies almost three billion miles from the Earth. Over the next 24 hours, it's hoped it will send back high resolution images of a planet no one has ever seen before. Here's our science correspondent Rebecca Morel. A mysterious world at last coming into view. These are the last images captured by new horizons as it closed in on Pluto, but there'll be nothing compared to the view from the flyby. WHISTLE BLOWS Its mission HQ in Maryland celebrations greeted the moment of closest approach. However, success won't be confirmed until the probe sends a signal back home. This mission's been a long time coming. We've visited every planet in our solar system, but not Pluto. It's a place we know almost nothing about. New horizons blasted off in 2006. It's had nearly five billion kilometres to the distant edge of the solar system. While the journey's been smooth, poor Pluto's had a more turbulent time. It was controversially demoted from a planet to a dwarf world, but that doesn't make its exploration any less thrilling. Here at New Horizons mission HQ, scientists have had to wait patiently for this moment for nearly a decade, but they say it's worth it. The images this spacecraft captures should be spectacular, showing features down to the size of a football pitch. Pluto's home, the Kuiper Belt, is where all eyes are now trained. It's a vast disk of space once thought empty, but scientists now believe it holds hundreds of thousands of icy worlds, comets and space rocks debris from the birth of the solar system. The moment Kuiper Belt is only something we study with telescopes, we've never had a mission passed through there, so it's an unexplored frontier of the solar system. Our understanding of Pluto is set to be transformed. If the missions worked, the first pictures from the flyby should arrive home tomorrow. At last revealing this hidden world. Rebecca Morrell, BBC News, New Horizons mission HQ.