New Horizons probe: New Pluto images 'tip of the iceberg'
New images of Pluto from Nasa's New Horizons probe have revealed strange plains on the surface of the planet.
A region, which has been named after the Soviet Sputnik satellite, displays a flat terrain broken up into polygons.
At the edges of these 20-30km-wide features are troughs filled with dark material and even small mounds.
Science correspondent Rebecca Morelle says these features suggest that the planet could be "geologically active now".
