The ‘floating hills’ of Pluto: Icebergs in a frozen nitrogen sea

Icebergs on Pluto: The large blocks of water ice float in a “sea” of nitrogen ice and are thought to have broken off from the rugged and mountainous highlands. Image Credit: NASA/JHUAPL/SwRI
Icebergs on Pluto: The large blocks of water ice float in a “sea” of nitrogen ice and are thought to have broken off from the rugged and mountainous highlands. Image Credit: NASA/JHUAPL/SwRI

Pluto is a tiny world and incredibly distant from the Sun, so it was a pleasant surprise for scientists last summer when the New Horizons spacecraft found that it is such a geologically active and dynamic place, with vast “seas” of nitrogen ice and glaciers, tall mountains of rock-hard water ice, and possible ice volcanoes. A new update this week focuses on some of the most interesting features discovered: iceberg-like blocks of water ice which “float” in the “seas” of softer nitrogen ice.

Read MoreThe ‘floating hills’ of Pluto: Icebergs in a frozen nitrogen sea