Pluto's mysterious polygons suggest the dwarf planet's heart has a pulse

Pluto's bright "heart" captivated astronomers and amateurs alike when NASA's New Horizons spacecraft beamed back the first clear images of the dwarf planet last July. But there's more to that distinctive shape than meets the eye.

In particular, the left lobe of the heart-shaped feature, informally dubbed Sputnik Planum, appears unusually smooth and plain at a glance. But when scientists took a closer look, they spotted a strange rubbly pattern across the expanse. Interlocking polygons appear to be etched into the surface of Sputnik Planum, slightly elevated in their centers, making the bright plain look as if snakeskin had been stretched across it....
http://www.csmonitor.com/Science/2016/0601/Does-Pluto-s-heart-have-a-pulse-Peculiar-polygons-suggest-activity-on-dwarf-planet