There are signs that Pluto is geologically active.<br /><br /> Images relayed by the first spacecraft to visit the planet show icy plains covered in uniform formations in the shape of polygons.<br /><br /> VIDEO: NASA's New Horizons team debuts a 'flyover' graphic of #Pluto's frozen plains. http://t.co/QHb9lyqwnK— Reuters Top News (@Reuters) 17 Juillet 2015<br /> <br /><br /> There are also clusters of hills and mountains.<br /><br /> Experts say the images, taken by the New Horizons mission which launched in 2006, show evidence of contraction on the planet’s surface.<br /><br /> They say the data – only one percent of the total captured by the probe – is challenging theories about how planets generate heat.
