NASA has released an enhanced colour image that zooms in on the southeastern portion of Pluto’s great ice plains where they meet rugged, dark highlands.
The dramatic image is the latest in the stunning series taken by the New Horizons spacecraft on its close fly-by last year.
The highlands have been named by NASA they Krun Macula (Krun is the lord of the underworld in the Mandaean religion, and a ‘macula’ is a dark feature on a planetary surface).
Scientists believe Pluto gets its dark red colour from tholins, complex molecules found across much of the surface. Tholins are formed by solar ultraviolet irradiation of simple organic compounds such as methane or ethane.
Krun Macula rises 2,500 metres above the surrounding plain – informally named Sputnik Planum – and is scarred by clusters of connected, roughly circular pits that typically reach between eight and 13 kilometres across, and up to 2,500 metres deep.
At the boundary with Sputnik Planum, these pits form deep valleys reaching more than 40 kilometres long, 20 kilometres wide and almost three kilometres deep – almost twice as deep as the Grand Canyon.
The floors of these valleys are covered with nitrogen ice. New Horizons scientists think these pits may have formed through surface collapse, although what may have prompted such a collapse is a mystery.