25th October 2013
An update on the New Horizons probe
New Horizons was launched by NASA in January 2006 to study the dwarf planet Pluto and return the first ever close-range photos of the distant world. This week, it reached another milestone on its long voyage.
The probe is now within 5 AU of Pluto. An astronomical unit (AU) is the average distance between the Earth and Sun – about 93 million miles, or 149 million kilometres. So far, New Horizons has travelled over 2.7 billion miles (4.4 billion km), which means it has completed 85% of its journey.
Alan Stern, New Horizons principal investigator: "It's exciting to be closing in on the Pluto system. The encounter begins in January 2015 – just over 14 months from now. You can really feel the energy level rising on this mission!"
After passing by Pluto, New Horizons will continue into the Kuiper belt, a region similar to the asteroid belt, but far larger – 20 times as wide and possibly 200 times as massive – and filled with icy remnants from the Solar System's formation. Mission planners are now searching for one or more additional Kuiper belt objects (KBOs) of around 50–100 km (31–62 mi) in diameter, for flybys similar to the spacecraft's Plutonian encounter.
By 2038, the probe will be 100 AU from the Sun. If still functioning, it will explore the outer heliosphere on the edge of interstellar space. After that, it will head in the direction of the constellation Sagittarius.