Sputnik Planum

Using computer models, New Horizons team members have been able to determine the depth of the layer of solid nitrogen ice within Pluto’s distinctive “heart” feature — a large plain informally known as Sputnik Planum — and how fast that ice is flowing. “For the first time, we can really determine what these strange welts of the icy surface of Pluto really are,” said William B. McKinnon, who led the study.